Re: [AMRadio] Thread change/License Class
Hay Brian your AM T Shirt went out today via priority mail... Is it ok to post them here as I still have some left HI !!! Bob W1PE On Oct 13, 2006, at 1:18 PM, A.R.S. - W5AMI wrote: On 10/13/06, Todd, KA1KAQ <[EMAIL PROTECTED]> wrote: On 10/13/06, Bob Maser <[EMAIL PROTECTED]> wrote: > On that subject, I can't > understand why the Advanced hams don't go down and pass the Extra written > exam, especially since the code requirements have been eliminated. Perhaps because some who hold lesser licenses are proud of the fact that they got their Advanced license when the Advanced test was more difficult than even the Extra was. Or perhaps they'd like to pass the 20WPM before getting the give-away Extra of today, but lack the time. Could be any number of things. Or maybe they don't want to be associated with some perceived arrogance of having an Extra ticket? Amen Todd. I'm an Advanced and I feel no less than any of the 5 wpm Extras of today for damned sure. Besides, I can't remember the last time I even operated in the Advanced sub-band on any band or mode. I'll probably upgrade one day, however my work is enough for me right now, trying to keep up with everything I need to do with it. Hpe to see you on 75 soon Todd! 73 Brian __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
[AMRadio] AM T SHIRTS
Hi Guys , I had some AM T Shirts made for the group here in Texas and still have some left over. The LOGO USED was the old TUNGSOL TUBE LGO with on the bottom AM GLOWS IN THE DARK. A Copy of the logo is on my website under the W1PE FORUM and go to the AM Page. They are a Dark Blue Shirt, No pocket. They come in L---XL---XXL and a couple of XXXL. Price is $11.00 for the L and XL $13.00 for the XXl and $14 for the XXXL. Postage is $4.50 via Priority Mail. Send checks to my QRZ adr... MO not required. My Web site adr is www.w1pe.com Thanks for reading guys... Bob W!pe __ AMRadio mailing list List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
[AMRadio] Resistor Needed
I am looking for a 40K 150 watt adjustable resistor. If you have one you can part with, please let me know. Not looking for a freebie Thanks es 73, Bob,W4WSZ___ Amradio mailing list List Home: http://w5ami.net/mailman/listinfo/amradio_w5ami.net Partner Website: http://www.amfone.net Post: mailto:Amradio@w5ami.net
[AMRadio] Mfg date for 4-400 series
According to the info that I have, they were in production in 1950. They were not listed in the 1948 data sheets. So it could be between 1948 and 1950. Hope this helps. 73, Bob, W4WSZ __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] 4-400
The info I posted has been confirmed by phone call to Eimac 73, Bob __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] 4-400 Facts
The following Eimac Tetrodes are listed in the Product Section in the 1947 Radio and Engineers Handbook: 4-65A, 4X100A, 4-125A, 4X150A, 4-250A, 4X500A and 4-1000A. I talked with their Engineering Department today and they confirmed that the 4-400 series began production in the very late 40's and was first listed in the 1950 Eimac Tube Product Guide. Since it is in my 1950 Eimac Catalog and not listed earlier, I think we can assume that Eimac is correct as to the dates of first production. 73, Bob,W4WSZ Eimac user for 55 yrs. __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] DX-100 parts
Don, I was over today helping an elderly ham get ready to dispose of everything prior to going into assisted living. I remember he had a box full of 1625's. They were not in boxes but were clean. You might want to make an offer and get all of them. Happy to help you on this end. 73, Bob, W4WSZ - Original Message - From: "Donald R. R Moore" <[EMAIL PROTECTED]> To: Sent: Monday, May 14, 2007 10:30 PM Subject: [AMRadio] DX-100 parts Have had some bad luck with my DX-100. I have a interminet meter, anyone got one? Also one of my 1625's went bad, does anyone have any for sale. Don W5FFK email [EMAIL PROTECTED] __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body. __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Partner Website: http://www.amfone.net Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] Still on AM
I started work as an announcer at age 15 at a local 250 watt broadcast station. The main reason at the time to get a ham ticket was to be able to run more power than the local station. I enjoyed signing off as the strongest station in town...hi I have been on AM since 1951built a lot of gear in the last 56 years...and at age 72, I am not even thinking about quiting. When you can have a career building and maintaining broadcast stationsit just doesn't get any better. Thanks for the memories, 73, Bob, W4WSZ __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] Tom Elmore
Tom, Your reply bounced. Bob,W4WSZ __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Average OP Age
Someone .. please..respond with your age so that I'm not the oldest buzzard here. I need the morale booster..hi 73 to all you youngsters Bob, W4WSZ Age 72 and On the Air since 1951 __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
[AMRadio] Thanks Tony
Tony, I wanted to take a moment and say thanks again for the DX contacts you provided me over the years. Always a pleasure to hear from you. 73, Bob, W4WSZ - Original Message - From: "Anthony W. DePrato" <[EMAIL PROTECTED]> To: "Discussion of AM Radio in the Amateur Service" Sent: Tuesday, July 24, 2007 9:07 AM Subject: RE: [AMRadio] KWS-1 on AM Phil: great story! I like to think the two stns are just setting waiting for the next team. 73 Tony QBE ZUT DE WA4JQS ANTHONY W. (Tony) DePrato WA4JQS EXTRA - HEAVY Since 1962 CQ DX HALL OF FAME # 35 A1-OP FISTS # 10573 SKCC #1227 South Sandwich Island Dxpedition Group CALLS HELD: WA4JQS/ZS1, WA4JQS/KC4, WA4JQS/4K1 ZD8JQS, V31SS, VP8BZL, VP8SSI, 3Y0PI __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body. __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] Average OP Age
Happy birthday John, I am sure you remember what it was like to sit in front of the FCC examiner. I took the exam for the First Phone Commercial the same waywhat a bugger 73, Bob, W4WSZ - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Tuesday, July 24, 2007 9:42 AM Subject: Re: [AMRadio] Average OP Age I am right behind you, Bob. I turned 70 on Sunday and have been licensed continuously since 1953. 73, John, W4AWM ** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body. __ AMRadio mailing list List Rules (must read!): http://w5ami.net/amradiofaq.html List Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net To unsubscribe, send an email to [EMAIL PROTECTED] with the word unsubscribe in the message body.
Re: [AMRadio] 807's triode connection question...
Hello Howard, I never ran 813s in triode connection, but here's what I have on the subject, from AM posts by Bill Kleronomos, KD0HG, and Mike Dorworthm K4XM. Also I believe the series screen grid resistor idea (about 4.7K unbypassed to each screen grid) should work with 813s in tetrode connection, if you want to play with that. Just be careful if you try it; if there is serious secondary emission, the screens won't behave as they need to for that mode of operation. But I think it will work. This hookup wants the same plate Z as comparable tetrode operation, but maybe 50V more is needed from the screen supply, which should be regulated, and slightly more negaive control grid bias to compensate for the higher quiescent screen voltage. Try different screen resistor values for minimum distortion. Bacon, WA3WDR - >From The AM Window website (www.amfone.org) Re: 813's as triodes Posted by Bill Kleronomos, KD0HG on November 12, 2000 at 23:09:44: The specs for triode connected 813s are : Max Ep= 2500, P-P load =~15,000, power out = 550W. Depending on the plate voltage, you'll need a few volts of bias which can be provided in the conventional manner. The u of a triode-connected 813 is 8.5. The exact P-P load Z and match isn't anywhere as important as the turns ratio between your mod transformer windings. To triode connect, tie G1 and G2 together and treat as one control grid. You can ground G3 and the internal shield. Look for a mod transformer (and any associated reactor)out of a 250-1000 watt broadcast transmitter, for starters. The iron out of a BC-610 or a T-368 would also be useable, but not quite as hi-fi at full power. A good resource for broadcast transmitter parts and contacting people that might have good junque is www.broadcast.net and http://radio-classifieds.com/classpro/viewads.html luck Bill Berthoud, Colo. Subject: [AMRadio] 813Triode info Date: Mon, 17 Apr 2000 10:17:58 -0400 From: "Mike Dorworth" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> AM Amateur Radio Reflector - http://www.bigcountry.com/w5ami Information on 813(T) found in ER 5, ER 15, ER 57. Calculated information (EXACT Values) to modulate 500 watts DC input @ 2250 VDC. 312 1/2 watts needed. 357 peak Ma, 114 mA Average. Plate to Plate load 19608 ohms 60 volts to grid (grid to grid 120 volts) Peak grid current 100 mA Driving power 3 watts. Tube voltage drop 500v at 0.357 amp peak. - Original Message - From: "Howard Aspinall" <[EMAIL PROTECTED]> To: "Bob Bruhns" <[EMAIL PROTECTED]> Sent: Friday, July 05, 2002 10:47 AM Subject: Fw: [AMRadio] 807's triode connection question... > Hi Bacon, > > This topic is all very interesting. I'm currently making > something using two pp 813 tubes in class B connected > the similar way as described for 807s. The books I've seen > on the subject give little or no info on this arrangement, > especially anode to anode resistance which presumably > differs from values for conventional class B for tetrodes. > > For instance for the 807 tube the 4th edition of the RSGB > Radio Communication Handbook gives the load resistance > in class AB1 with 750v plate voltage as 7k ohms and for > triode connected class B with same plate voltage as 6650 > ohms > > I'm planning to drive the 813s from a valve hi fi > amp giving up to 50 watts out at 15 ohms, into a > hi fi o/p tranny connected in reverse as driver > tranny for the class B amp. > > Is there any available history or info on use of > 813s in this application, and is there any easy > way of calculating or anticipating the anode to anode > resistance of the tubes used this way. > > This may be interest to otherss on the AM list, > so feel free to quote my message, if appropriate. > > I'm still experimenting with negative cycle loading > etc with super results on 160m > > 73..Howard/G3RXH > > > - Original Message - > From: Bob Bruhns <[EMAIL PROTECTED]> > To: > Sent: Thursday, July 04, 2002 4:55 PM > Subject: Re: [AMRadio] 807's triode connection question... > > > > Hi Vince, > > > > Use lower modulator plate voltages, and/or set up the mod > > transformer taps for relatively high impedance to the tube > > plates. If you raise the plate to plate impedance, it will > > cause increased screen dissipation in tetrodes and pentodes, > > so be careful. If the plate-to-plate impedance would differ > > greatly from typical values, you should reduce the modulator > > plate voltage and use ordinary impedances instead. > > > > This sort of thing is the main reason for any concern about > > impedance in a classic power amplifier. The impedance > > presented will affect the current that the ampl
Re: [AMRadio] Station Monitor
Steve...SB610 $75.00 to $125.00 is the best or the Kenwood SM220 $200.00 up I paid $250 for mine... Bob K1JNN At 10:21 AM 7/9/02 -0400, you wrote: Good morning, I am on my way in putting together a station to get on the air AM. I was just wondering as far as a scope to monitor station perfomance is there anyone prefered over the others? Secondly if anyone has an extra they would part with I would definitly be interested in it. Have a great day and thanks. 73 Steve N4TKP Bartow, Florida ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Bandwidth
3 KHz bandwidth for all amateur transmissions? Well, they're going to hear from the packet, ATV, FM and satellite amateurs if they try to pull this stunt. This had better be electromagnetic legend. I hope they know what they would be getting into here. But it seems to me that we've heard about this before. Wasn't it the head of the ARRL, on a 15 KHz wide FM repeater, who shot his mouth off about a 3 KHz bandwidth limit - and then backed down and said he was only kidding? Bacon, WA3WDR
Re: [AMRadio] Radio Polizania
Hi Don, It really is amazing how we are becoming more and more restricted, here in the home of the free. And it's only going to get worse. All of this is protecting incompetent, lowballer industrialists, who could have put security into their products, but chose not to. As a result, there will be no security... and any half-assed spy can hear it all! But the big boys will certainly get their cut. Priorities are priorities! And the beat goes on... Bacon, WA3WDR - Original Message - From: "Donald Chester" <[EMAIL PROTECTED]> To: Sent: Tuesday, July 23, 2002 2:30 PM Subject: [AMRadio] Radio Polizania > > From last week's Telecom Digest and DX Listener's Digest (forwarded to me by > e-mail): > > > ** U S A. House Radio Bill > http://www.mail-archive.com/cypherpunks-moderated%40minder.net/msg01 671.html > > Dave Emery (N1PRE)'s outstanding review of the radio reception provisions in > the Cyber Electronic Security Act passed by the House on Monday, July 15. > > "In effect this removes a safe harbor created during the negotiations over > the ECPA back in 1985-86 which ensured that first offenses for hobby radio > listening were only treated as minor crimes - after this law is passed > SIMPLY INTENTIONALLY TUNING A COMMON SCANNER to the (non-blocked) cordless > phone frequencies could be prosecuted as a > felony for which one could serve 5 years in jail. ..." > > And there's more, including changed provisions related to the publication of > material heard by radio. > > http://www.newsignals.com http://www.spectrumfinder.net > (Benn Kobb, July 17, DX LISTENING DIGEST) > > ** U S A. [WUN] MAJOR CHANGE TO THE ECPA THAT IMPACTS EVERYONE... > Date: Wed, 17 Jul 2002 11:46:01 -0400 > From: Dave Emery [EMAIL PROTECTED] > To: [EMAIL PROTECTED], [EMAIL PROTECTED] > > Something of enormous importance to radio hobbyists has just happened in > Washington, and so far I haven't seen any mention or discussion of it on any > scanner or ham lists I follow. I hope this message will alert others to > what has just happened and get people thinking about the consequences... > > The House just passed the Cyber Security Enhancement Act (HR3482) last night > (7/15/02) by an overwhelming margin of 385-3. Buried in an otherwise > draconian bill that raises penalties for computer hacking that causes death > or serious injury to life in prison and allows government monitoring of > communications and email without warrants in even more circumstances is the > following seeming obscure language: > > : SEC. 108. PROTECTING PRIVACY. > : > : (a) Section 2511- Section 2511(4) of title 18, United > : States Code, is amended-- > : > : (1) by striking paragraph (b); and > : > : (2) by redesignating paragraph (c) as paragraph (b). > > For those of you who don't realize what this means > > USC Section 2511 subsection 4 of title 18 (the ECPA) currently reads as > foilows the CSEA will strike part (b) of this language. > > Penalties.. > > : (a) > : > : Except as provided in paragraph (b) of this subsection > : or in subsection (5), whoever violates subsection (1) > : of this section shall be fined under this title or > : imprisoned not more than five years, or both. > : > : > > [The following section will be eliminated by the new law...] > > : (b) > : > : If the offense is a first offense under paragraph (a) > : of this subsection and is not for a tortious or illegal > : purpose or for purposes of direct or indirect commercial > : advantage or private commercial gain, and the wire or > : electronic communication with respect to which the > : offense under paragraph (a) is a radio communication that > : is not scrambled, encrypted, or transmitted using > : modulation techniques the essential parameters of > : which have been withheld from the public with the > : intention of preserving the privacy of such communication, > : then - > : > : (i) > : > : if the communication is not the radio portion of a > : cellular telephone communication, a cordless telephone > : communication that is transmitted between the cordless > : telephone handset and the base unit, a public land > : mobile radio service communication or a paging service > : communication, and the conduct is not that described > : in subsection (5), the offender shall be fined under > : this title or imprisoned not more than one year, or > : both; and > : > : (ii) > : > : if the communication is the radio portion of a > : cellular telephone communication, a cordless telephone > : communication that is transmitted between the cordless > : telephone handset and the base unit, a public land > : mobile radio service communication or a paging service > : communication, the offender shall be fined under this > : title. > > What this does is change the penalty for the first offense of intercepting > an unscrambled and unencrypted radio communication that is not supposed to > be listened to (e.g. AMPS cellular calls, c
[AMRadio] Trade nos Stancor A-3894 poly-pedance 125 watt modulation xfmr
Hi, Possibly someone out there needs this new in the box modulation xfmr? It will match from 2000-20,000 ohms in both primary and secondary with max audio power at 125 watts ... 225Ma on both primary & secondary. Never used in original box. I built a new rig pair of 4-400a's modulated by triode connected 813's. The plate power xfmr a very old Thordason 6000vct shorted out. I'm looking for a replacement that will be able to go 3000-3500 at 500Ma. So a 1500v at 1 amp in a doubler would work as will 2500-3000v at 500Ma or 6000vct at 500Ma.what do you have? Used ok 73 Bob, AA8A
[AMRadio] Trade nos Stancor A-3894 poly-pedance 125 watt modulation xfmr
Hi, Possibly someone out there needs this new in the box modulation xfmr? It will match from 2000-20,000 ohms in both primary and secondary with audio power at 125 watts ... 225Ma on both primary & secondary. Never used ,in original box. I built a new rig pair of 4-400a's class C modulated by triode connected 813's. The plate power xfmr a very old Thordason 6000vct shorted out. I'm looking for a replacement that will be able to go 3000-3500 at 500Ma. So a ~ 1500v at 1 amp in a doubler would work as will 2500-3000v at 500Ma or 6000vct at 500Ma.what do you have? Used ok 73 Bob, AA8A
Re: [AMRadio] Trade nos Stancor A-3894 poly-pedance 125 watt modulation xfmr
Hi Paul, Thanks for your offer. Need more info are the first two 115vac primaries or 230/115? My first thought is that the 3000vct used in a bridge would give more than 3kv at half the current and that would be ok. Can you describe the 3000vct size, weight. Is it potted...manufacturer? 73, Bob AA8A At 06:46 PM 8/9/2002 -0700, you wrote: Bob, I have a 5000vct at 500 ma and a 3000 vct at 1 amp. Also a 5000 vct at 1 amp but it only has a 115 v primary (about 28 amps). will trade any 1 for your modulation transformer. Tel: 760-375-4505 or email: [EMAIL PROTECTED] - -Original Message- From: Bob Login <[EMAIL PROTECTED]> To: AMRadio@mailman.qth.net Date: Friday, August 09, 2002 3:58 PM Subject: [AMRadio] Trade nos Stancor A-3894 poly-pedance 125 watt modulation xfmr >Hi, Possibly someone out there needs this new in the box modulation xfmr? >It will match from 2000-20,000 ohms in both primary and secondary with >audio power at >125 watts ... 225Ma on both primary & secondary. Never used ,in original box. > >I built a new rig pair of 4-400a's class C modulated by triode connected >813's. The plate power xfmr a very old >Thordason 6000vct shorted out. I'm looking for a replacement that will be >able to go 3000-3500 at 500Ma. >So a ~ 1500v at 1 amp in a doubler would work as will 2500-3000v at 500Ma >or 6000vct at 500Ma.what do you have? >Used ok >73 Bob, AA8A > >___ >AMRadio mailing list >AMRadio@mailman.qth.net >http://mailman.qth.net/mailman/listinfo/amradio ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Trade nos Stancor A-3894 poly-pedance 125 watt modulation xfmr
Hi Bill, Thanks for the offerhave some other options to ck out first but your xfmr would do the jobcan you give me the dimensions. Where did it come from/mfg? Is it potted...how iswell I suppose the picture would be FB.Thank you, Bob At 04:45 PM 8/9/2002 -0700, you wrote: Hi, Bob I have a 6000 volt ct transformer, with a 120v tapped hi/lo primary. Should be good for at least an amp. Weighs 53 pounds. I can send a pix if you are interested. Not looking for a trade, though, am trying to lighten the load around here. I'd take $75 plus shipping. 73 de Bill, AB6MT [EMAIL PROTECTED] - Original Message - From: "Bob Login" <[EMAIL PROTECTED]> To: Sent: Friday, August 09, 2002 2:40 PM Subject: [AMRadio] Trade nos Stancor A-3894 poly-pedance 125 watt modulation xfmr > Hi, Possibly someone out there needs this new in the box modulation xfmr? > It will match from 2000-20,000 ohms in both primary and secondary with max > audio power at > 125 watts ... 225Ma on both primary & secondary. Never used in original box. > > I built a new rig pair of 4-400a's modulated by triode connected 813's. The > plate power xfmr a very old > Thordason 6000vct shorted out. I'm looking for a replacement that will be > able to go 3000-3500 at 500Ma. > So a 1500v at 1 amp in a doubler would work as will 2500-3000v at 500Ma or > 6000vct at 500Ma.what do you have? > Used ok > 73 Bob, AA8A > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Trade nos Stancor A-3894 poly-pedance 125 watt modulation xfmr
Paul, If your suggesting I pay you $190 to ship it lets forget it. Thanks anyhowBob At 04:13 PM 8/10/2002 -0700, you wrote: The first 2 are 115 or 230v. The 3000 v job is hermetically sealed and will deliver 700 ma in a bridge or 1.4 amp in a full wave. They ar all very heavy but can be shipped by UPS. about $70 on the west coast and about $190 on the East coast. To see some pictures look at my web page: http://www1.iwvisp.com/cinnabar/page4.html Hope this helps. - - -Original Message- From: Bob Login <[EMAIL PROTECTED]> To: amradio@mailman.qth.net Date: Friday, August 09, 2002 7:23 PM Subject: Re: [AMRadio] Trade nos Stancor A-3894 poly-pedance 125 watt modulation xfmr >Hi Paul, Thanks for your offer. Need more info >are the first two 115vac primaries or 230/115? My first >thought is that the 3000vct used in a bridge >would give more than 3kv at half the current >and that would be ok. Can you describe the >3000vct size, weight. Is it potted...manufacturer? > > >73, Bob AA8A > > >At 06:46 PM 8/9/2002 -0700, you wrote: >>Bob, I have a 5000vct at 500 ma and a 3000 vct at 1 amp. Also a >>5000 vct at 1 amp but it only has a 115 v primary (about 28 amps). >>will trade any 1 for your modulation transformer. >>Tel: 760-375-4505 or email: [EMAIL PROTECTED] >>------ --- >> >>-Original Message- >>From: Bob Login <[EMAIL PROTECTED]> >>To: AMRadio@mailman.qth.net >>Date: Friday, August 09, 2002 3:58 PM >>Subject: [AMRadio] Trade nos Stancor A-3894 poly-pedance 125 watt modulation >>xfmr >> >> >> >Hi, Possibly someone out there needs this new in the box modulation xfmr? >> >It will match from 2000-20,000 ohms in both primary and secondary with >> >audio power at >> >125 watts ... 225Ma on both primary & secondary. Never used ,in original >>box. >> > >> >I built a new rig pair of 4-400a's class C modulated by triode connected >> >813's. The plate power xfmr a very old >> >Thordason 6000vct shorted out. I'm looking for a replacement that will be >> >able to go 3000-3500 at 500Ma. >> >So a ~ 1500v at 1 amp in a doubler would work as will 2500-3000v at 500Ma >> >or 6000vct at 500Ma.what do you have? >> >Used ok >> >73 Bob, AA8A >> > >> >___ >> >AMRadio mailing list >> >AMRadio@mailman.qth.net >> >http://mailman.qth.net/mailman/listinfo/amradio >> >>___ >>AMRadio mailing list >>AMRadio@mailman.qth.net >>http://mailman.qth.net/mailman/listinfo/amradio > >___ >AMRadio mailing list >AMRadio@mailman.qth.net >http://mailman.qth.net/mailman/listinfo/amradio ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Docket 20777 again!
Don...Talked with Jim Haynie yesterday about this.Like he said and please do not quote me that they have not told him what to petition the FCC on and that there has not been a time frame set to do it...I really do not think that he is in favor after he saw all the interest in AM at our special Event at HAMCOM...We have a very large contingent of AMers on our local repeater that are on him all the time Bob At 05:17 AM 8/14/02 +, you wrote: Minute 64 adopted at the most recent ARRL Board of Directors meeting on July 19-20, 2002: http://www.arrl.org/announce/board-0207/ 64. On motion of Mr. Frenaye, seconded by Mr. Stinson, it was VOTED that at the next practical opportunity the ARRL shall petition the FCC to revise Part 97 to regulate subbands by signal bandwidth instead of by mode. The last time that was tried, back in the 70's, the proposed bandwidths were 350 Hz and 3.5 kHz. That was Docket 20777, the infamous FCC proposal that would have killed AM on the HF bands. It was only through the strong response of the AM community that the measure was rejected. We need to get busy on this one! Don K4KYV _ MSN Photos is the easiest way to share and print your photos: http://photos.msn.com/support/worldwide.aspx ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Fw: Minute 64 adopted at the most recent ARRL Board of Directors meeting on ...
Let's not get hostile toward the ARRL, or we will very likely produce a self-fulfilling prophecy. ARRL has been pretty positive toward AM as a classic mode in recent years. Give them a chance, but certainly look out for surprises. Bacon, WA3WDR - Original Message - From: "K0PJG" <[EMAIL PROTECTED]> To: "Dale Parfitt" <[EMAIL PROTECTED]>; ; <[EMAIL PROTECTED]> Cc: <[EMAIL PROTECTED]>; "Howard Mills" <[EMAIL PROTECTED]>; "Dennis" <[EMAIL PROTECTED]>; "Andy" <[EMAIL PROTECTED]> Sent: Thursday, August 15, 2002 7:41 PM Subject: [AMRadio] Fw: Minute 64 adopted at the most recent ARRL Board of Directors meeting on ... Hello Dale, Will I am not one to shy away from standing up for AM, but read the response from our ARRL Pres. ; Have they just not been specific enough on Minute 64 or is there something afoot Watson ? Tom - K0PJG - Original Message - From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Thursday, August 15, 2002 1:08 PM Subject: Re: Minute 64 adopted at the most recent ARRL Board of Directors meeting on ... "The ARRL is petitioning the FCC to regulate subbands by bandwidth. 1. First off, we do not have a petition. 2. You can't work phone in the subbands now. 3. What we are interested in is two new modes of digital. Clover 2000 and Pactor 3. 4. Under the present rules, 300 baud RTTY is the signal width standard. Clover 2000 and Pactor 3 are a bit wider. It is felt that by being able to accommodate these two new technologies, amateur radio would be in compliance with its charge under part 97 to "promote and enhance the art" 5. Presently our technical team is looking at what frame work is needed to accomplish the new modes. I hope this helps and if you would pass it on so as to quell the fears of the AM'ers. 73 Jim Haynie, W5JBP President, ARRL --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. Please post in Plain-Text only.--- ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
[AMRadio] RANGER PRICING
Well its time for my 2 cents worth...As a kid I could not afford a Ranger...I ran a DX35 and a VF-1 and lusted for the Ranger...Bought a Ranger II for $275 and sent it to Dee...When I got it back $500 plus latter I think that I have one of the nicest Rangers around...Dee did a great job...It looks great and everyone says it sounds greatWould have loved to buy the $500 Ranger but out of cash right nowI see nothing wrong with asking top dollar if you deliver top $$ gearSome of us are not the best at restoration as Dee and others are so we pay for it!!! Thats all...Bob K1JNN
Re: [AMRadio] Re: Heathkit Warrior amplifier
Hi Carl and others...I use my warrior on AM with very good results...I drive it with a Ranger II at 15 watts and get about 200 watts out...When modulated about 250Runs a little warm but witstands my longwinded mouth...Hi!!! I love the Warrior..according to Heath it should run about 400watts...Don't think the 811 A would like it... Best 73's Bob K1JNN At 06:59 PM 9/6/02 -0500, John Beasley wrote: Give my little brother Carl (WBØHTW) a shout. He's done a very nice job restoring mine. I'll send pictures if you like. I don't think it has a lot of headroom for AM, however, it looks really nice next to an Rx-1 & TX-1. [EMAIL PROTECTED] --... ...-- WAØSTX, John - Original Message - From: "Ron Samchuk" <[EMAIL PROTECTED]> To: Sent: Friday, September 06, 2002 3:51 PM Subject: [AMRadio] Re: Heathkit Warrior amplifier > Hi everyone again on the AM reflector. I just made a deal to get a Heathkit > Warrior amplifier (uses four 8-11a tubes). It is supposed to be working, > but does anyone out there have any comments one way or the other on this > amp? I seem to rememeber previous negative remarks on the Warrior HA10, but > I can't remember what the concern was. I seen a photo of this one and it > looks good and the price was very reasonsable. I couldn't pass the > opportunity to get a matching unit for my Apache and Mohawk! Thanks in > advance for any responses. Regards from Ron VE4SR > > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] No Kids, No Lids.......
Oh yeah - Stan!!! OH, BOY... Stanislaus, are you around? Is Anybody Around??? OH BOY, Doubleyew One T Jayyy E in PUTNAM, Connecticut, STANDING BY. What a parade of great characters! Bacon, WA3WDR - Original Message - From: "Me, Myself and I" <[EMAIL PROTECTED]> To: Sent: Monday, September 09, 2002 4:05 PM Subject: Re: [AMRadio] No Kids, No Lids... > I remember a gentleman with the suffix of 'TJX' using that many years > ago... he used the phonetics of 'tare Jig X-ray' > > 73 > Vince > ka1iic > > > > On Mon, 9 Sep 2002, Bill Coleman wrote: > > > W2OY Lancaster, NY: "No kids, no lids, no school bus riders." I was all > > three, lived abt 8 miles away. Tuff time getting my DX-35 heard thru Mike's > > BC-610. > > > > Bill ColemanN2BC > > http://home.stny.rr.com/n2bc > > - Original Message - > > From: <[EMAIL PROTECTED]> > > To: > > Sent: Monday, September 09, 2002 8:53 AM > > Subject: [AMRadio] No Kids, No Lids... > > > > > > > I believe that famous CQ speech originated with a W8 in Ohio in the late > > > 50's. Don't remember his call, but it was a two letter suffix. It went > > > something like this: > > > "CQCQ...CQ ..No Kids, No Lids, No K calls, No Space > > Cadets,. > > > this is W8xx". I remember how disappointed I was to hear it because I was > > a > > > kid with a "K call" at the time. I don't remember the rest of it, but > > > remember hearing it many times around 1959-60 time frame on 40M AM.. > > While > > > we are walking down memory lane, anybody remember W3EBM ."Three Empty > > > Beer Mugs"? I think he was in Scranton, PA. I was in awe of his booming > > > signal on 40M AM from a Johnson Desk KW back in 1959. Wow! he would peg > > the > > > S-meter and rattle the speaker Hi, Hi. > > > 73, Jack, W9GT > > > > > > http://mywebpages.comcast.net/w9gt/index.htm > > > - Original Message - > > > From: "Jeff Edmonson" <[EMAIL PROTECTED]> > > > To: > > > Sent: Sunday, September 08, 2002 9:17 PM > > > Subject: Re: [AMRadio] Subbands and FCC > > > > > > > > > > > > > > > NO kids NO lids (grin!) > > > > > > > > "No lids, no kids, no space cadets, no school bus drivers." ;-) > > > > > > > > Who has/knows the full text of that? It was someone's CQ, > > > > and the first time I heard about it, was from Floyd/WA5TWF > > > > ex-President/S.P.A.M.*, now a silent key since 1987. > > > > > > > > > > > > 73 = Best Regards, > > > > -=Jeff/W5OMR=- > > > > > > > > * = "S.PA.M. = Society for the Preservation of Amplitude Modulation" > > > > > > > > > > > > ___ > > > > AMRadio mailing list > > > > AMRadio@mailman.qth.net > > > > http://mailman.qth.net/mailman/listinfo/amradio > > > > > > ___ > > > AMRadio mailing list > > > AMRadio@mailman.qth.net > > > http://mailman.qth.net/mailman/listinfo/amradio > > > > > > > > > ___ > > AMRadio mailing list > > AMRadio@mailman.qth.net > > http://mailman.qth.net/mailman/listinfo/amradio > > > > Don't resolve with words that which can be taken care of with a flame > thrower... > > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] No Kids, No Lids.......
Correction. I forgot the phonetics: OH, BOY... Stanislaus, are you around? Is Anybody Around??? OH BOY... Double-you One T Jayyy EDouble-you One TEAR JIGG EX-Ray in PUTNAM, Connecticut, STANDING BY. Bacon, WA3WDR - Original Message - From: "Bob Bruhns" <[EMAIL PROTECTED]> To: Sent: Monday, September 09, 2002 7:52 PM Subject: Re: [AMRadio] No Kids, No Lids... > Oh yeah - Stan!!! > > OH, BOY... Stanislaus, are you around? Is Anybody Around??? OH > BOY, Doubleyew One T Jayyy E in PUTNAM, > Connecticut, STANDING BY. > > What a parade of great characters! > > Bacon, WA3WDR > > > - Original Message - > From: "Me, Myself and I" <[EMAIL PROTECTED]> > To: > Sent: Monday, September 09, 2002 4:05 PM > Subject: Re: [AMRadio] No Kids, No Lids... > > > > I remember a gentleman with the suffix of 'TJX' using that many > years > > ago... he used the phonetics of 'tare Jig X-ray' > > > > 73 > > Vince > > ka1iic > > > > > > > > On Mon, 9 Sep 2002, Bill Coleman wrote: > > > > > W2OY Lancaster, NY: "No kids, no lids, no school bus riders." > I was all > > > three, lived abt 8 miles away. Tuff time getting my DX-35 heard > thru Mike's > > > BC-610. > > > > > > Bill ColemanN2BC > > > http://home.stny.rr.com/n2bc > > > - Original Message - > > > From: <[EMAIL PROTECTED]> > > > To: > > > Sent: Monday, September 09, 2002 8:53 AM > > > Subject: [AMRadio] No Kids, No Lids... > > > > > > > > > > I believe that famous CQ speech originated with a W8 in Ohio > in the late > > > > 50's. Don't remember his call, but it was a two letter > suffix. It went > > > > something like this: > > > > "CQCQ...CQ ..No Kids, No Lids, No K calls, No Space > > > Cadets,. > > > > this is W8xx". I remember how disappointed I was to hear it > because I was > > > a > > > > kid with a "K call" at the time. I don't remember the rest of > it, but > > > > remember hearing it many times around 1959-60 time frame on > 40M AM.. > > > While > > > > we are walking down memory lane, anybody remember W3EBM > ."Three Empty > > > > Beer Mugs"? I think he was in Scranton, PA. I was in awe of > his booming > > > > signal on 40M AM from a Johnson Desk KW back in 1959. Wow! he > would peg > > > the > > > > S-meter and rattle the speaker Hi, Hi. > > > > 73, Jack, W9GT > > > > > > > > http://mywebpages.comcast.net/w9gt/index.htm > > > > - Original Message - > > > > From: "Jeff Edmonson" <[EMAIL PROTECTED]> > > > > To: > > > > Sent: Sunday, September 08, 2002 9:17 PM > > > > Subject: Re: [AMRadio] Subbands and FCC > > > > > > > > > > > > > > > > > > > NO kids NO lids (grin!) > > > > > > > > > > "No lids, no kids, no space cadets, no school bus drivers." > ;-) > > > > > > > > > > Who has/knows the full text of that? It was someone's CQ, > > > > > and the first time I heard about it, was from Floyd/WA5TWF > > > > > ex-President/S.P.A.M.*, now a silent key since 1987. > > > > > > > > > > > > > > > 73 = Best Regards, > > > > > -=Jeff/W5OMR=- > > > > > > > > > > * = "S.PA.M. = Society for the Preservation of Amplitude > Modulation" > > > > > > > > > > > > > > > ___ > > > > > AMRadio mailing list > > > > > AMRadio@mailman.qth.net > > > > > http://mailman.qth.net/mailman/listinfo/amradio > > > > > > > > ___ > > > > AMRadio mailing list > > > > AMRadio@mailman.qth.net > > > > http://mailman.qth.net/mailman/listinfo/amradio > > > > > > > > > > > > > ___ > > > AMRadio mailing list > > > AMRadio@mailman.qth.net > > > http://mailman.qth.net/mailman/listinfo/amradio > > > > > > > Don't resolve with words that which can be taken care of with a > flame > > thrower... > > > > > > ___ > > AMRadio mailing list > > AMRadio@mailman.qth.net > > http://mailman.qth.net/mailman/listinfo/amradio > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Support the ARRL
I am a longtime AMer, an old timer at this point, since around 1966 (on the ham bands). I had played around with 1620 in the old days, but the FCC convinced me that wasn't a good idea. CB too. I have generally been an ARRL member over the years. Although I considered them kind of parental, and despite their disinterest in, and general opposition to amateur AM, I had to acknowledge their contribution to the continued existence of ham radio. And I still do. When I moved to Virginia in 1996, I soon discovered the technical group known as AMRAD, and I joined. It turns out that the president of AMRAD is Paul Rinaldo, the ARRL Technical Relations Manager, formerly QST Editor and ARRL Technical Department Manager, and a fellow who is often reviled for his real or perceived pro-FCC/anti-AM stance over the years. Knowing Paul now, seeing him traveling all over the world literally all the time, in pursuit of the survival and possibly the expansion of ham radio, I don't hold any grudge. Many guys like Paul at the ARRL are fighting for the survival of ham radio every day. They are constantly parrying some commercial attack on amateur frequencies. They are trying to make ham radio interesting for newcomers, and trying to help them get started. They publish the ARRL Handbook, one of the most useful publications in the whole field of radio. The list goes on and on. Pretty much nobody else is doing anything. We know how clever they are. They are using those wits to defend ham radio. With AM, I think they thought they were doing the right thing. No, it wasn't good. But I'll tell you this: messing with AM is about the last thing on their minds these days. Ham radio is what they are about. Yes, they have to survive financially to do their work. We better hope they can continue. People have to realize that amateur radio is not a right guaranteed by scripture, or the Constitution, etc. It is a gift from the pioneers of radio, a gift that we need to protect and defend. There are conflicts between real-world political necessities and the "boistrous sea of liberty," as Irb W2VJZ might call it, but we should recognize, respect and support those who are defending and trying to stimulate our hobby. They are working hard. They are not just a bunch of fun-hating old cronies. You should meet them some time. I support the ARRL. That's why. Bacon, WA3WDR
Re: [AMRadio] Eurpoean AM gear as seen in Dr. "No"
Heh heh... Back in the 60s when that show first aired, my friend Don, WB2UKA, sent Fred Gwynne (the actor who played Hermann Munster) a reception report, but complained that he was receiving TVI from his station... Gwynne was a ham, and he responded in good natured fun. Bacon, WA3WDR - Original Message - From: "Freeberg, Scott (STP)" <[EMAIL PROTECTED]> To: Sent: Monday, December 09, 2002 10:29 AM Subject: RE: [AMRadio] Eurpoean AM gear as seen in Dr. "No" While not as glamorous as "Dr. NO", I hesitantly confess to watching "The Munsters" last Friday night. Herman is sitting in front of a large homebrew looking tube radio. He's busy contacting 'martians' who turn out to be the neighbor kids on a walky talkly (AM of course). :^)) 73, Scott WA9WFA ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
[AMRadio] ULTIMATE BA
For Pick up only in Arlington,TXThis is a complete 100% Ship Board station. Has AM/SSB/RTTY/CW... Xmtr is 100% tube Receiver is Solid State. It is an ITT Mackay Marine Type MRU-29B/30B/34A...Manufactured in July 72. All Manuals are included...It is 3 racks at a weight of about 600 Lbs. This uses a pair of 813's Modulated by 813's...As an extra there is a 500 KC Emergency transmitter All of the above for $750.00. I have not seen it but all items are boxed and out of the racks... This is from the XYL of a local SK...He actually took it off the ship when his XYL left the Merchant Marines as a Radio operator...All cabling instructions are in the manual. Best 73's Bob K1JNN/5 Mesquite, TX 75149 --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. To learn how to post in Plain-Text go to: http://www.expita.com/nomime.html ---
Re: [AMRadio] Modulation Monitors
Jim Charlie Goodrich still maintains the McMartin gear he lives in Omaha,NBProbably listed in the phone book Bob At 07:42 AM 2/17/03 -0700, you wrote: Hi All: I have come across a couple of AM modulation monitors and would like to make them work for me. Can anyone direct me to a source for manuals or at least schematics for a McMartin TBM 8500 and a Belar AMM-2? I would be deeply grateful. 73 Jim de W5JO ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio Best 73's Bob K1JNN/5 Mesquite, Tx 75149 --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. To learn how to post in Plain-Text go to: http://www.expita.com/nomime.html ---
[AMRadio] W1AW/5
Hi Folks well our Texas AM group got itWe will be operating W1AW/5 during HAMCOM 2003 ARRL National Convention In Arlington in June. This will be a 100% sanctioned by the ARRL Event. We need all the AMERS support on this very important 3 days of operating. We will have a special certificate for all that operate and all of you that contact us If you can make plans to come on June 20...21...22 go to HAMCOM.ORG and register and get with one of us to sign up to operate. The event coordinator is Mike WA5CMIWe will be inside next to the ARRL booth. Mike will be doing an article for ER soon. Best 73's Bob K1JNN/5 Mesquite, TX 75149 --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. To learn how to post in Plain-Text go to: http://www.expita.com/nomime.html ---
Re: [AMRadio] Throat Mike
No personal experience with the T-30, but I have worked with modern throat mics. You have to boost the highs like crazy! I don't have the documentation any more, but I remember like 50 dB of rise from 300 to 3500 Hz. With the right EQ, they aren't bad. However - even with these mics that I worked with, probably about the best in the industry, some people just don't come through well. There was this big fat guy who just sounded like mush. I guess if the skin is thick and floppy around the neck, the sound picked up there will be especially muffled. There was some experimentation done with bone conduction pickup on the side of the nose. Also some experimentation was done with a "skull" mic, that picked up sound from bone conduction in the skull. Bacon, WA3WDR - Original Message - From: <[EMAIL PROTECTED]> To: ; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Friday, March 21, 2003 4:41 PM Subject: [AMRadio] Throat Mike > All, > > I recently picked up a WW2 T-30 throat microphone at a fleamarket. Hooked > it up to my ART-13 and made a few tests with my friends here in Southern > California. The universal report was very muffled, restricted and only > marginally intelligible audio, the same results I remember from the last time > I played with a throat mic back in the 50s. The unit was in very good > condition, BTW, and had very high output -- modulated the ART-13 fully. > > My question here is, was there a particular communication technique, method > of articulation, special vocabulary, etc., which had to be used with these > things?Hard to believe they were satisfactory for operational use. Has > anyone had personal experience here? > > Dennis D. W7QHO > Glendale, CA > > > > --- StripMime Report -- processed MIME parts --- > multipart/alternative > text/plain (text body -- kept) > text/html > The reason this message is shown is because the post was in HTML > or had an attachment. Attachments are not allowed. To learn how > to post in Plain-Text go to: ttp://www.expita.com/nomime.html --- > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Throat Mike
Hi Don, With 55 dB of boost at 3500 Hz, a throat mic does pick up the "s" sound. You can even distinguish S from SH. In fact, don't whistle, because the other people will complain. There is a definite GNYENG-GNYENG quality to the speech, but it is quite intelligible. It can sound really funny when a deep-water diver is breathing a helium mix. HA!!! With so much gain and EQ, it gets noisy, especially with six live throat mics on a system. I deliberately screwed up the low end tracking of a 2:1 analog compansion system to make it act like a gentle noise gate, and it really helped this. Each mic had a 2:1 on its radio link, and the return bus also had 2:1. A little skew, and the noise became tolerable, not an issue. That was one of my last mods before I left that company. Oh man, you also have to be careful to have the throat mic muted while you put the thing on. Otherwise, the scratching noises will blow out everybody's ears. 55 dB of boost... Yeowch! A good system should have peak limiting with some top end boost in the level detector. There are also ear mics on the market. They don't sound so good, and they pick up lots of extraneous noise. That's not good, because usually you want a non-air mic to block out noise, although sometimes it's to allow underwater speech while using SCUBA gear. I think for most purposes, a throat mic is the way to go if you can't use an air mic. Bacon, WA3WDR - Original Message - From: "Donald Chester" <[EMAIL PROTECTED]> To: Sent: Friday, March 21, 2003 10:37 PM Subject: Re: [AMRadio] Throat Mike > > I never have figured out how a throat mike is supposed to work. There is no > way it could pick up the articulation of speech, like the "s" sounds. It > would seem to me the speech would come through with all vowels and no > consonants. The things always reminded me of an April Fool joke. > > Don K4KYV > > _ > Help STOP SPAM with the new MSN 8 and get 2 months FREE* > http://join.msn.com/?page=features/junkmail > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] AM Bulletin Board
OH BOY! Now we'll REALLY be seeing hits!!! Stupid spam. Bacon, WA3WDR - Original Message - From: "Neal Newman" <[EMAIL PROTECTED]> To: Sent: Monday, April 14, 2003 6:56 PM Subject: Re: [AMRadio] AM Bulletin Board > and I thought I was alone with this Problem... > Neal Ka2caf > > "Darrell, WA5VGO" wrote: > > > Well, some wise guy has foul up the AM Bulletin board. All I did was go to > > the bulletin board and now every time I open it, a porno site also opens > > up. It is getting past my fire wall. Does anyone know how to get rid of the > > problem? > > > > Thanks, > > Darrell, WA5VGO > > > > ___ > > AMRadio mailing list > > AMRadio@mailman.qth.net > > http://mailman.qth.net/mailman/listinfo/amradio > > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] AM Bulletin Board
The automatic porn link got removed. The AM Radio Bulletin Board is OK now. Although it might happen again if the idiot posts again. Bacon, WA3WDR - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Monday, April 14, 2003 7:52 PM Subject: Re: [AMRadio] AM Bulletin Board > No problem here. Works fine for me. > Pete > > On Mon, 14 Apr 2003 18:56:19 -0400 Neal Newman <[EMAIL PROTECTED]> > writes: > > and I thought I was alone with this Problem... > > Neal Ka2caf > > > > "Darrell, WA5VGO" wrote: > > > > > Well, some wise guy has foul up the AM Bulletin board. All I did > > was go to > > > the bulletin board and now every time I open it, a porno site also > > opens > > > up. It is getting past my fire wall. Does anyone know how to get > > rid of the > > > problem? > > > > > > Thanks, > > > Darrell, WA5VGO > > > Sign Up for Juno Platinum Internet Access Today > Only $9.95 per month! > Visit www.juno.com > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
[AMRadio] W1AW/5 at HAMCOM 2003
Notice to all AMers...The Texas NOS 3.880 group is sponsoring a 3 day special event at HAMCOM 2003 the ARRL National Convention. No one at ARRL knows for sure the last time that W1AW was on AM. We have a great certificate to give away both to guest ops and to all that we contact. SASE to the PO Box that is listed in QST.We are setting up on June 19th and will be on 40 meters that afternoon and then from Friday 7 AM through the opening hours of HAMCOM. Fqs operated will be + or - 3.880, 7.290 , 14.290. We will only have 100 watts but will have a great antenna and a 75A4 receiver. Check the June QST for all the info. Best 73's Bob W1PE Mesquite, TX 75149 --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. To learn how to post in Plain-Text go to: http://www.expita.com/nomime.html ---
Re: [AMRadio] AM Power Level
Hi Joe, Generally for 100% positive modulation, 1500W PEP translates into a 375Watt carrier. (These are output levels.) But in the real work=ld, this ain't necessarily so... Check WA5BXO's website, there is some interesting reading on AM power regarding carrier and modulation vs. PEP. http://www.qsl.net/wa5bxo/ In particular on John's WA5BXO site, check AM Tech Page, Natural Asymmetrical Modulation, and Amplitude Modulation and PEP. Bacon, WA3WDR - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Sunday, May 18, 2003 1:14 PM Subject: [AMRadio] AM Power Level > I'm a new subscriber to the list, and I have not discovered the way to do a search > through the old archives. Forgive me if this has already been covered. > > I'm currently in the process of collecting the parts to build a Class-E Am transmitter > and Class-H modulator for 75 meters. (I was quite surprised at the relative > simplicity of the circuit!) While I have been a boatanchor collector for years, and > also an on-and-off-again Electric radio subscriber (though I have every issue) I have > never yet been on the air in AM mode. Listening on 75 off and on over the years > has me itching to finally change that. > > I'm interested to know if I understand the newer FCC power guidelines correctly and > how peak power on AM is measured. The FCC now stipulates 1500 watts peak > output. Am I correct in understanding that in AM, the peak output at 100% > modulation is four times the carrier level? Does this mean that if one is to be strictly > within the FCC rules, you can have a carrier of only 375 watts in the AM mode? > > My proposed transmitter will be capable of a unmodulated 600 watt carrier. > Fortunately, it appears to be a simple matter to reduce power in a Class-E amp just > by lowering the supply / modulation voltage to the MOSFET drains. > > Any help in furthering my understanding is appreciated. > > Thanks! > > 73, > Joe > N6DGY > > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
[AMRadio] HAMCOM AM W1AW/5
Last posting on this subject...Just want to remind all that we will be on the air from HAMCOM starting Friday AM...We will be on during HAMCOM hours...The Freqs are3.880.7.290.14.290... All of course plus or minus...A very nice certificate will also be sent out upon receipt of your QSL and an SASE...We will be running a Viking II and 75A4 and also a B&W 5100B and an HRO5TA1. For those of you attending come by and operate and receive a certificate. If you attend we will be having an AM Forum Friday the 20th at 1500...We are also having a Pizza AM get together Saturday night at 1830 till wheneverIt is at CiCi's Pizza so all you can eat very cheap No beer though...Hope to see ya all at HAMCOM next weekend. Best 73's Bob W1PE X K1JNN Mesquite, TX 75149 --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. To learn how to post in Plain-Text go to: http://www.expita.com/nomime.html ---
Re: [AMRadio] HAMCOM AM W1AW/5
No I don't Dave sorry..Butch and Jay still have some...I sold all of mine!!! They are up to about $50 for a new one Bob At 05:05 AM 6/15/03 -0400, you wrote: Bob, do you have a copy of Jay's Pocket Guide? I have a friend in England that would dearly love to get a copy. What does the "PE" stand for phonetically? David Knepper - W3ST Secretary to the Collins Radio Association (CRA) Publisher of the Collins Journal www.collinsra.com CRA station call - W3CRA - Original Message - From: "Bob Peters" <[EMAIL PROTECTED]> To: ; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]> Sent: Saturday, June 14, 2003 9:27 PM Subject: [AMRadio] HAMCOM AM W1AW/5 > Last posting on this subject...Just want to remind all that we will be on > the air from HAMCOM > starting Friday AM...We will be on during HAMCOM hours...The Freqs > are3.880.7.290.14.290... > All of course plus or minus...A very nice certificate will also be sent > out upon receipt of your QSL > and an SASE...We will be running a Viking II and 75A4 and also a B&W > 5100B and an HRO5TA1. > For those of you attending come by and operate and receive a certificate. > > If you attend we will be having an AM Forum Friday the 20th at > 1500...We are also having a Pizza > AM get together Saturday night at 1830 till wheneverIt is at CiCi's > Pizza so all you can eat very > cheap No beer though...Hope to see ya all at HAMCOM next weekend. > > Best 73's Bob W1PE X K1JNN > Mesquite, TX 75149 > > --- StripMime Report -- processed MIME parts --- > multipart/alternative > text/plain (text body -- kept) > text/html > The reason this message is shown is because the post was in HTML > or had an attachment. Attachments are not allowed. To learn how > to post in Plain-Text go to: http://www.expita.com/nomime.html --- > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio _______ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio Best 73's Bob W1PE Mesquite, TX 75149 --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. To learn how to post in Plain-Text go to: http://www.expita.com/nomime.html ---
[AMRadio] Classic Exchange
Listen for the AM Station coming from the Channel 5 NBC5i Expo in Dallas...Viking II with a 75A4 on 7.290 and 14.285 both + or - ...Call sign W5D...Checked it all out today 5X5...Looking forward to a lot of QSO's between 9AM and 5 PM Saturday and Sunday Best 73's Bob W1PE Mesquite, TX 75149 --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. To learn how to post in Plain-Text go to: http://www.expita.com/nomime.html ---
Re: [AMRadio] FW: Homebrew receiver
I think the SX-28 audio is pretty much the same as the SX-25. Superb!
Re: [AMRadio] What's A "Isophon Lautsprecher"?
I think it's a speaker. See if you get a little click if you put an ohmmeter across the terminals. I was imagining a label on it, saying "Der Loudenspeaker ist nicht fur gefingerpoken." Loosely translated that would mean "no user serviceable parts inside." - Original Message - From: "Merz Donald S" <[EMAIL PROTECTED]> To: ; <[EMAIL PROTECTED]>; <[EMAIL PROTECTED]>; "'Glowbugs (E-mail)" <[EMAIL PROTECTED]> Sent: Monday, December 01, 2003 2:43 PM Subject: [AMRadio] What's A "Isophon Lautsprecher"? Hmmm...What I have here is 2 small packages about 3 inches square and 1 inch deep. The label on each one says "Isophon Lautsprecher St HB 7 S228". Inside each package is a 1/2 inch thick bakelite and aluminum assembly with a grille on one side and 2 wires on the other. The label on the back of each of these is the same as on the package. Molded into the back of each one is "Made in Germany". Hmmm...it doesn't say "made in West Germany" and it is too old to be made in post-USSR-breakup Germany. So I conclude that these were made in pre-war Nazi Deutschland. Anyone? Any Guesses? Any referrals to someone who might know? These were found in an estate in a paper Cameradio bag on which was written "electro-static". Any that's all the clues I've got to give you. Any help appreciated. Thanks. 73, Don Merz, N3RHT DISCLAIMER: The information contained in this e-mail may be confidential and is intended solely for the use of the named addressee. Access, copying or re-use of the e-mail or any information contained therein by any other person is not authorized. If you are not the intended recipient please notify us immediately by returning the e-mail to the originator.(A) ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Book WANTED...!
I made that mistake myself... in 1961, the Russians were building
the Berlin Wall, and kind of menacing traffic to and from West
Berlin. Parallels to the 1948 blockade were drawn, and newsreel
photos of the 1948 airlift were shown. Not having witnessed the
events of 1948, I thought the airlift was happening in 1961.
1961 was when JFK called himself a pastry ("Ich bin ein Berliner!")
in his speech of support in West Berlin. German, like other
languages, can be idiomatic. "Berliner" would normally have
referred to one who lives in Berlin; but since a "Berliner" is a
particular pastry item, it happened to have an unexpected meaning!
Still, the people of West Berlin appreciated his message.
Bacon, WA3WDR
- Original Message -
From: "Donald Chester" <[EMAIL PROTECTED]>
To: ; <[EMAIL PROTECTED]>;
<[EMAIL PROTECTED]>;
<[EMAIL PROTECTED]>;
<[EMAIL PROTECTED]>
Sent: Tuesday, December 02, 2003 7:38 PM
Subject: RE: [AMRadio] Book WANTED...!
>
>
> >The other error I noticed is that the author talks about the
Berlin Airlift
> >taking place in 1961--oops--it was actually 1948.
> >
>
> I betcha he got the date confused with the summer of 1961.
Wasn't that
> when the Berlin Wall went up?
>
> I have a copy of the book, but I'm afraid I don't want to part
with mine.
>
> Don K4KYV
>
> _
> Wonder if the latest virus has gotten to your computer? Find out.
Run the
> FREE McAfee online computer scan on your PC now!
> http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963
>
> ___
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> AMRadio@mailman.qth.net
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Re: [AMRadio] Johnson Desk
Fluorescent light tubes are a much bigger source of mercury, because of the huge number of them that are tossed annually. Incinerator smoke scrubbers can not deal with mercury emissions at all; they just send the mercury airborne! This is a primary source of mercury in our environment now. Bacon, WA3WDR - Original Message - From: "Brett Gazdzinski" <[EMAIL PROTECTED]> To: Sent: Friday, December 05, 2003 8:03 AM Subject: RE: [AMRadio] Johnson Desk > Well, for $5000.00, anyone could build a VERY nice plate modulated > kilowattor a few. > Including Peter Dahl iron, and a nice cabinet to put it in. > > Many classic rigs demand a very high price for nostalgia, not because > they are good transmitters, or a good value dollar for watt. > > I suppose its a good investment, the price is bound to only go up. > > Why do I very rarely ever hear a desk kilowatt on the air? > > The 500 was also a very nice piece of equipment, you don't see many of > those... > > Brett > N2DTS > > > > > > > > > > I certainly mean no offense, Joe... however, think about it > > this way: > > > > > > who in their right mind would screw-over someone who has the > > resources > > > to make life a living hell? > > > > I don't have the resources, I guarantee it! And in the > > business I've done > > with them, one transaction involving a significant chunk of > > change, I have > > NOT been screwed. I've been quite happy! If I had a loose $5K, I > > wouldn't hesitate to by that Desk. I'd love to have have it. > > It's a nice > > looking radio, and the actual "desk" is in pretty good shape, too. > > Unfortunately, I have to eat > > > > Yes, the 500-D was badly done -- according to the review. > > It's not the > > only attempt at a good idea that didn't turn out well in the amateur > > maretplace. > > > > But all of the snide remarks from a lot pf people who have never done > > business with myvintageradios isn't called for. Even if you > > think you could > > get the same piece of gear in mint condition for $50.00 or know where > > there's one in a land fill somewhere. > > > > I'm not defending the seller, but geez guys ... give it a > > freakin' break ... > > > > Grant/NQ5T > > > > ___ > > AMRadio mailing list > > AMRadio@mailman.qth.net > > http://mailman.qth.net/mailman/listinfo/amradio > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] WTD: DX-100 Manual and knob
I believe the Apache used EL-34s for modulators. I am not sure what other AM rigs might have used 6146 for modulator tubes, other than the Valiant. Maybe the B&W5100? What did it use for modulators? Bacon, WA3WDR - Original Message - From: "Tommye & Jim Wilhite" <[EMAIL PROTECTED]> To: Sent: Monday, January 05, 2004 10:12 PM Subject: Re: [AMRadio] WTD: DX-100 Manual and knob > This is correct. Very little difference except for cabinet design. The > Apache used 6146s as mod tubes. > > 73 Jim > de W5JO > > - Original Message - > From: "Larry Knapp" <[EMAIL PROTECTED]> > To: > Sent: Monday, January 05, 2004 6:56 PM > Subject: Re: [AMRadio] WTD: DX-100 Manual and knob > > > > Just a clarification."the B model and they used 6146s as modulators in > > place of the 1625s"No, the DX-100B also uses 1625's as modulators. > The > > Johnson Valiant uses 6146's as modulators...do not believe any Heathkit > used > > 6146's as modulators. > > > > 73, Larry KC8JX > > > > --- Tommye & Jim Wilhite <[EMAIL PROTECTED]> wrote: > > > Don: > > > > > > The biggest difference in DX 100s is the use of a step cap in the output > > > circuit like the Johnson Valiant used. If you have it there will be a > step > > > switch to increase the values. > > > > > > There was a mod kit sold to replace those caps with a variable one and > later > > > versions may have the variable cap furnished with it. > > > > > > That is about the only differences in DX 100s until you get into the B > model > > > and they used 6146s as modulators in place of the 1625s. > > > > > > Which version do you have? > > > > > > 73 Jim > > > de W5JO > > > > > > - Original Message - > > > From: "Merz Donald S" <[EMAIL PROTECTED]> > > > Sent: Monday, January 05, 2004 9:14 AM > > > Subject: [AMRadio] WTD: DX-100 Manual and knob > > > > > > > > > I need a DX-100 manual copy. But weren't there different versions of > this > > > TX? Are the differences such that I need to make sure the manual I get > > > matches the version I have? How do I tell which version I have? > > > > > > This one also has an unoriginal knob in the center below the dial. If > anyone > > > has an original knob, I could use that too. > > > > > > Thanks. > > > 73, Don Merz, N3RHT > > > > > > __ > > Do you Yahoo!? > > Yahoo! Hotjobs: Enter the "Signing Bonus" Sweepstakes > > http://hotjobs.sweepstakes.yahoo.com/signingbonus > > ___ > > AMRadio mailing list > > AMRadio@mailman.qth.net > > http://mailman.qth.net/mailman/listinfo/amradio > > > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Mike Cable Capacitance
Hi John, Crystal and ceramic mikes (piezoelectric mikes) generally act like a combination of a relatively low impedance source (I don't know exactly, a few thousand ohms or so), coming through a series capacitance of roughly 500pF. This tiny internal effective output coupling capacitance is the reason that we need a very high load resistance to maintain the low frequency response. A 15 foot cable with 30 pF per foot would present a 450 pF capacitance to ground, and this would work with the piezo microphone's effective output capacitance to act as a capacitive voltage divider, which would cut the mike level about in half (-6dB), or about 100% to about 50% modulation, which is about what was observed. The effect of this capacitive voltage division should be uniform across the audio frequency range, but the load resistance causes another effect at the low frequency end.. The total effective series capacitive reactance would be equal to the effective microphone output capacitance and the cable capacitance in parallel, or about 950 pF, so in this example the presence of the 15 foot cable would reduce the mike level by about 6 dB, and the relative low frequency response with any given load resistance would be extended down by about an octave. That can be a dramatic response difference if the low frequency cutoff is in the 300Hz range. Bacon, WA3WDR - Original Message - From: "John Coleman" <[EMAIL PROTECTED]> To: Sent: Thursday, January 15, 2004 11:08 AM Subject: RE: [AMRadio] Mike Cable Capacitance One of us, and it very well could have been me, must have missed something. I though Bret, N2DTS, said that the coupling problem (loss of audio level and high frequency response) was the cable from the preamp to a power amp using line level coupling. I was only mentioning that a high Z input, such as an old style XTAL mic input on the power amp would be a typical problem as you mentioned. But I don't think he is using that scenario. I think Bret said that he had a preamp for the mic and that it was the coupling cable from the output of the preamp to a power amp line input that was in question and that replacement with a very short cable increased the audio level and high frequency response. This doesn't seem very normal to me, that changing from a 15 ft to a 1 ft cable at normal line level medium impedances would make that much difference in frequency response and especially a noticeable gain difference form 20% modulation to 100% or more. A friend of mine is noted for placing resistors and capacitors inside a cable connector for the purpose of EQ or attenuation, rather than modifying the equipment. You have to be careful about using just any old cable in his place; it may have a 1 meg resistor in series with the cable built into the connector end. HIHI. John, WA5BXO -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jim Bromley Sent: Thursday, January 15, 2004 4:06 AM To: AM Radio List Subject: [AMRadio] Mike Cable Capacitance John Coleman, WA5BXO, posted: (Regarding 50-ohm coax attenuating the high audio frequencies when used as a microphone cable). > I feel there must be some other thing that is overlooked > about the connector or cable. 15 ft of cable would not > normally cause any noticeable effect on audio unless the > terminating Z was greater that a few mega ohms as it would > be for some of the older equipment made for Xtal mike input > but I can't imagine a modern day line input being greater > than 100K ohms The impedance to be concerned with in this case is not the terminating impedance, but rather the source impedance of the microphone itself. In the case of the D-104, although the impedance of the microphone is specified at a nominal 10K-ohms, its actual source impedance is much higher. It is a well-known fact that the element must be terminated in a resistive impedance of at least 10-Megohms to obtain adequate low-frequency response - indicating a source impedance of at least that amount. Additionally, since there is no DC path through a crystal acoustic transducer, one would be suspicious that whatever the actual source impedance is, it would contain a capacitive reactance as a series component. The best solution to the problem is that advocated by several other posters here - incorporate a preamplifier very close to the microphone element (inches, not feet, away) having an imput impedance in the tens of megohms and capable of driving a 500-ohm termination at unity gain. Jim Bromley, K7JEB Glendale, AZ James E. BromleyTel: 623-848-8711 5128 N. 69th Ave. E-Mail: [EMAIL PROTECTED] Glendale, Arizona 85303 ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Mike Cable Capacitance
Hmm, so the mike cable isn't the problem, it's the cable from the preamp to the modulator. I can't believe that any commercial audio gear would have such high output impedance that fifteen feet of cable capacitance would make much difference. And I don't think that the difference between fifteen feet of RF cable and fifteen feet of audio cable would make much difference at all. Now, musicians with high impedance guitar pickups can often tell the difference between guitar cables that are not much longer than 15 feet... and it does affect the highs. But a guitar pickup is a tricky, high impedance, highly inductive signal source. It seems more likely to me that maybe the preamp has a floating balanced output, and only one side is connected to the shielded line, and the shield is grounded. Output in that situation would be very quirky, and dependent on the load impedance and any bypass capacitance. If you had, say, 100pF to ground on either side at the preamp balanced output, and 100pF to ground at the modulator input (and I assume that the modulator input is single-ended), then it would act like a capacitive divider again, with 200pF effective capacitance to a low-z audio source. The resistive load would affect the low end, and varying cable capacitance would affect the level and the low frequency corner as well. However, if the bypass caps were 4700 pf or .01 uF, the effect of cable capacitance would be slight. For a few hundred pF of cable capacitance to affect the top end much, there would have to be only a very small amount of extra bypass capacitance. Maybe someone made a passive low-pass filter at the preamp output, and the extra cable capacitance is having a big effect on an unintended resonance. (Doubtful.) Or maybe there is some RF getting in that is getting rectified and causing an audio resonance when you transmit. Different cable, even a different cable path, can affect RF leakage. Do the RG cable and the Radio Shack cable have their own connectors, or did you replace the RG with the Radio Shack cable using the same connectors? And does the preamp use those 3-pin XLR connectors? That would suggest a probable balanced audio output. I really suspect something like a balanced output (and/or input) that is not connected right. To use a floating balanced output for a single ended system, just ground one side and take output from the other. Balanced windings are usually not center-tapped, but they might be set up for phantom power somehow... which is another possible source of odd effects if the winding is not connected right. The other likely possibility is RF rectification. I would run a variable oscillator through the preamp and measure response and output at various points with a VTVM or a modern digital meter, and see where the weird stuff is coming from. That's the best thing. Or you could feed some music source into the preamp, put the transmitter on a dummy load, and listen with a receiver while you change stuff. The differences you saw were large, and you should be able to track them down. Also, just try it as-is, but first with the transmitter on an antenna, and again on a dummy load, and see if that makes a difference. Could be RF rectification. Bacon, WA3WDR
Re: [AMRadio] re: Ham Radio songs out there?
Hi Ron, Yes there is, if I can ever find the tape now... "Yes, The Frequency's In Use" was sung as a barber-shop quartet (a capella; vocal lead, and three-part harmony backup) reply to some idiot who repeatedly besieged the AM window with "Is the frequency in use?" from some digital recorder or sequencer, back around 1990. I have the tape somewhere, I think... I'll search for it again this summer. Bacon, WA3WDR - Original Message - From: "Ron Samchuk" <[EMAIL PROTECTED]> To: Sent: Wednesday, March 10, 2004 5:41 PM Subject: [AMRadio] re: Ham Radio songs out there? Hi everyone... I just received from another ham a great musical item called "CQ Serenade" and I was wondering if there are any similar songs relating to ham radio, especially AM operating. Thanks from Ron VE4SR --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. To learn how to post in Plain-Text go to: http://www.expita.com/nomime.html --- ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] URL check
No problem with access here. Odd things happen on the net... and sometimes
we have to flush the buffer ("Delete Files"), etc.
Bacon, WA3WDR
- Original Message -
From: "Mark Foltarz" <[EMAIL PROTECTED]>
To: ; <[EMAIL PROTECTED]>
Sent: Saturday, March 13, 2004 1:17 PM
Subject: [AMRadio] URL check
> Guys,
>
> Could you goto www.lakeerieba.com and tell me if you can access and
navigate
> the site?
>
> I am getting a complaint that the site is not accessible. However, I
can't
> duplicate the problem - nor can I find anyone who cannot access the site
> either.
>
> Thanks
>
> de KA4JVY
>
> Mark
>
> __
> Do you Yahoo!?
> Yahoo! Mail - More reliable, more storage, less spam
> http://mail.yahoo.com
> ___
> AMRadio mailing list
> AMRadio@mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/amradio
>
Re: [AMRadio] Plate modulating a 807
Bob, the main problem I see with that circuit is that the plate current meter will get blasted by the modulator output. This will present an unhappy load to the modulator as well. The connection down to S1 from B+ should come from the R20 side of the MOD jumper,instead of the R17/C21 side, so that when S1 is switched to the plate position, M1 is across R20. If R24 is 10K or more, the 807 screen may self-modulate enough to work reasonably on AM. Series-resistor screen self-modulation occurs for the same reason a choke provides modulation; screen current is inversely affected by plate voltage. What is the value of R24, and what is the voltage on the bus being fed from R17? Also, what is the value of 807 screen bypass capacitor C24? C24 should not be very large, or it will produce excessive rolloff in screen modulation at higher audio frequencies. (A small compensating capacitor can be added between modulated B+ and the screen to improve screen modulation at the higher audio frequencies, but that would be a final touch.) If R24 is merely a fuse-resistor for the 807 screen, you will want to make a change for better quality modulation. The simplest change would be a series choke of several Henries between R24 and the 807 screen circuit. Alternatively, you could add a larger dropping resistor from unmodulated B+, or a divider resistor pair one from the 807 screen to modulated B+, and one from the 807 screen to unmodulated B+. That will give the best modulation linearity, if properly proportioned. However, if you modulate the screen from resistors going up to plate voltage, you will probably want to add a clamp tube to the 807 screen circuit as well. Bacon, WA3WDR - Original Message - From: "RJ Mattson" <[EMAIL PROTECTED]> To: Sent: Tuesday, April 06, 2004 11:19 PM Subject: [AMRadio] Plate modulating a 807 > This url is to my Hammarlund Four20 AM transmitter schematic. > http://www.hvinet.com/rjmattson/four20schematic > The PA 807 screen does not seem to be modulated through a dropping > resistor or self modulated with a choke. The Hammarlund Four11 > plate modulator is connected in place of jumper MOD on the > schematic. Should I try it as is or rewire? > > bob...w2ami > www.qrz.com/callsign/w2ami > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Plate modulating a 807
Hi Bob, With the plate meter connection moved to R20, I think the 807 screen will self-modulate reasonably well with a 15K screen resistor - but the 0.01uF screen bypass is too big. Probably it should be 1000pF to the 807 cathode, with maybe about 300pF to modulated B+. Maybe the screen bypass goes to the cathode instead of ground, because it is an RF bypass for a wide frequency range? Actually, I don't know which ground is best, but whatever works is OK with me. A 300pF capacitor to modulated B+ and a 1000pF capacitor to the cathode (effectively ground) would make a capacitive voltage divider. If we have (let's say) 55% modulation on the screen, that's +/-110V peak, or 220Vp-p on the 200VDC on the screen meanwhile there would be 100% modulation on the plate, or +/-470V peak, or 940V p-p, on the 470VDC on the plate. The ratio of screen audio to plate audio is 220 to 940, or 0.234:1. So the capacitive divider needs to aim for 23.4% of the plate swing going to the screen, and it will enforce this at very high audio frequencies. 300pF and 1000pF divides to 0.231, or 23.1%, which is close enough. If the self-modulation of the 807 screen produces less than the above amount of voltage swing on the screen, then the 300pF capacitor can be reduced in value to match it, or a more complex screen resistor setup can be arrranged to increase the amount of 807 screen modulation. However, the latter will involve a resistor to modulated B+, and therefore might call for the use of a clamp tube. For now, take the simple route and reduce the 300pF cap value as needed.. Bacon, WA3WDR - Original Message - From: "RJ Mattson" <[EMAIL PROTECTED]> To: Cc: <[EMAIL PROTECTED]> Sent: Thursday, April 08, 2004 12:57 AM Subject: Re: [AMRadio] Plate modulating a 807 > I agree, the 100ma meter should be across the shunt R20 (27ohm). I will > check if that is a drafting error. > > Here is a marked up transmitter drawing showing the values in question: > http://www.hvinet.com/rjmattson/four20schematic+ > > R24 screen is 15 K > Screen voltage is 200V > R24 node is 270V > C24 screen bypass is .01mfd. Why is bypass to cathode and not ground? > Plate voltage is 470V > > The Hammarlund Four11 plate modulator is two 7C5s in PP (8K ohm xfmr sec) > > Should the screen self modulate as wired? (with plate meter corrected) > > Thanks, > bob...w2ami > www.qrz.com/callsign/w2ami > > - Original Message - > From: "Bob Bruhns" <[EMAIL PROTECTED]> > > > Bob, the main problem I see with that circuit is that the plate current > > meter will get blasted by the modulator output. This will present an > > unhappy load to the modulator as well. The connection down to S1 from B+ > > should come from the R20 side of the MOD jumper,instead of the R17/C21 > side, > > so that when S1 is switched to the plate position, M1 is across R20. > > > > If R24 is 10K or more, the 807 screen may self-modulate enough to work > > reasonably on AM. Series-resistor screen self-modulation occurs for the > > same reason a choke provides modulation; screen current is inversely > > affected by plate voltage. > > > > What is the value of R24, and what is the voltage on the bus being fed > from > > R17? Also, what is the value of 807 screen bypass capacitor C24? C24 > > should not be very large, or it will produce excessive rolloff in screen > > modulation at higher audio frequencies. (A small compensating capacitor > can > > be added between modulated B+ and the screen to improve screen modulation > at > > the higher audio frequencies, but that would be a final touch.) > > > > If R24 is merely a fuse-resistor for the 807 screen, you will want to make > a > > change for better quality modulation. The simplest change would be a > series > > choke of several Henries between R24 and the 807 screen circuit. > > Alternatively, you could add a larger dropping resistor from unmodulated > B+, > > or a divider resistor pair one from the 807 screen to modulated B+, and > one > > from the 807 screen to unmodulated B+. That will give the best modulation > > linearity, if properly proportioned. However, if you modulate the screen > > from resistors going up to plate voltage, you will probably want to add a > > clamp tube to the 807 screen circuit as well. > > > > Bacon, WA3WDR > > > > > > - Original Message - > > > This url is to my Hammarlund Four20 AM transmitter schematic. > > > http://www.hvinet.com/rjmattson/four20schematic > > > The PA 807 screen does not seem to be modulated through a dropping > > > resistor or self modulated with a choke. The Hammarlund Four11 > > > plate modulator is connected in place of jumper MOD on the > > > schematic. Should I try it as is or rewire? > > > > > > bob...w2ami > >
Re: [AMRadio] Plate modulating a 807
Hi John, Since the last correspondence in this thread that you had received, I got one sent by W7QHO on 4/8/2004 at 1:18AM EDT, I sent one on 4/8/2004 at 2:52AM \EDT, and got one more from RJ Mattson sent 4/8/2004 at 9:13AM EDT, that I didn't answer yet. Then (of course) yours sent 4/9/2004 at 11:05PM EDT, and W7QHOs reply sent 4/10/2004 at 1:18AM EDT. Hmm, I was looking at the cathode capacitor... but it is shunted by the cathode resistor (R18), which is 100 ohms. to ground. The 807 will act as a cathode follower driving audio onto C27 and R18, but I think the cathode will be within about a few volts of ground potential at audio frequencies, so my guess is that a 0.01uF going from the screen to the cathode of the 807 will act like maybe 0.008 or 0.009uF to actual ground, for audio. Slightly reduced, but still pretty much a 0.01uF. This 0.008uF (a guess) will face the 15K in parallel with the screen impedance, or maybe 5K combined (another guess). I think it is too large for high audio frequencies. But you should be able to do tests at low audio frequencies below about 400 Hz. Actualy, R18 ought to produce negative audio feedback, and reduce modulation distortion in the 807. I'll have to think about that. Bacon, WA3WDR - Original Message - From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; Sent: Saturday, April 10, 2004 1:18 AM Subject: Re: [AMRadio] Plate modulating a 807 In a message dated 4/9/04 8:07:33 PM, [EMAIL PROTECTED] writes: > I have a feeling that I am only getting some of the reflected email. I > have not received back two dup ones that I sent and I can find no other > mention of the subject below. Is any one else experiencing this? > Yes! Dennis D. W7QHO Glendale, CA --- StripMime Report -- processed MIME parts --- multipart/alternative text/plain (text body -- kept) text/html The reason this message is shown is because the post was in HTML or had an attachment. Attachments are not allowed. To learn how to post in Plain-Text go to: http://www.expita.com/nomime.html --- ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Plate modulating a 807
Hi John, Since the last message you received in this thread ( from RJ Mattson, sent 4/8/2004 at 1:10AM EDT), I got: one sent by W7QHO on 4/8/2004 at 1:18AM EDT, one from me, sent 4/8/2004 at 2:52AM EDT, one from RJ Mattson sent 4/8/2004 at 9:13AM EDT, one from you, sent 4/9/2004 at 11:05PM, one from W7QHO, sent 4/10/2004 at 1:18AM EDT, one from me, sent 4/10/2004 at 4:21AM EDT and now one from you, sent 4/10/2004 at 10:19AM EDT - Original Message - From: "John Coleman, ARS WA5BXO" <[EMAIL PROTECTED]> To: Sent: Saturday, April 10, 2004 10:19 AM Subject: RE: [AMRadio] Plate modulating a 807 > > I might also add, that I have net received the message of my own, back > from the reflector, that is as follows. > > QUOTE > I have a feeling that I am only getting some of the reflected email. I > have not received back two dup ones that I sent and I can find no other > mention of the subject below. Is any one else experiencing this? > > John, WA5BXO > > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of RJ Mattson > Sent: Thursday, April 08, 2004 12:11 AM > To: AM Radio > Subject: [AMRadio] Plate modulating a 807 > > Sorry > Here is a marked up transmitter drawing showing the values in question: > http://www.hvinet.com/rjmattson/four20schematic_mu > > bob...w2ami > > END QUOTE > > Weird stuff!! > > John, WA5BXO > > > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] Modulation Question
Hi Ed, Some scopes don't sync well, either because of bad design from day one, or because of old age. You may do better to just let the horizontal sweep free-run, or lock it to the power mains. Other than that, you could experiment with the trigger settings. You want something around 2 milliseconds per division sweep rate. A compressor definitely helps, but if there is a lot of phase distortion in the modulator, it will only do so much. The better you get the transmit audio chain and the modulated stage, the more a processor will prevent overmodulation. There are also some multi-diode high-level clipper circuits that help by preventing the overmodulation in the first place. If this is done right, it helps, but it does introduce some harmonic distortion and therefore some splatter. The more gradual the "clipping," the less distortion and splatter. It also helps to get the modulation to the screens set up right. The original circuit was not ideal. It takes modulated B+ and sends it through a resistor to the screens, but this attempts to apply 100% mod to the screens, and they work better with less than 100% mod applied to them. Too much mod to the screens tends to cause a sudden pinch-off of the RF envelope at around 90% negative modulation. That results in distortion, splatter and sudden overmodulation, which is just what you don't want. The best approach is to replace the original single screen resistor with two higher-value resistors, one going to unmodulated B+ and the other going to modulated B+. These two resistors should be proportioned to give the right amount of modulation, and the same amount of screen current as before. As I recall, the ratio was about 60% of the screen current from modulated B+, and 40% of the screen current from unmodulated B+. Look for an article Dino WA1KNX on this subject, probably on this website, and also in back issues of the AM Press Exchange. By the way, I recall that there was a fairly obvious connection error in the original hand-drawn schematic from the first edition of this article, so be careful if you find an old edition - inspect the circuit. Bacon, WA3WDR - Original Message - From: "Edward B Richards" <[EMAIL PROTECTED]> To: Sent: Wednesday, April 14, 2004 8:03 PM Subject: [AMRadio] Modulation Question > Hi Guys; > > I am new to this list so please forgive me if my questions are dumb or > redundant. I just rebuilt a much abused Heathkit DX-100B. As far as I can > tell it is operating OK into a dummy load. I have not put it on the air > yet. For one thing, I don't have a 75 meter antenna up yet. I have a > mobile ant I will install as soon as I have time. I do have a MFJ G5RV jr > that is good for 40 meters and higher. I have not heard any AM on > anything but 75 meters. Is there activity on 40 and / or 20 meters? > > I modified a scope to serve as a modulation monitor. I noticed 2 things > that puzzle me. > > 1. It is hard to tell modulation percent with voice as the waveform keeps > changing and unless I use a sine wave I can't sync it to get a good > envelope pattern. Any trick to this? > > 2. Using the mod mon I see that it is very easy to over-modulate. If I > keep the modulation down so I don't see short bright lines in the center > of the screen (carrier disappearing, I think) , the average modulation is > around 50% except for occasional peaks. Is this normal? would a > compression amplifier help? Thank you. > > 73, Ed Richards K6UUZ > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio >
Re: [AMRadio] Modulation Question
Hi again, Ed. Oops, - this isn't the website I was thinking about.. heh heh. Oh yes... it's a mailing list! I remember... I remember... Check Dino's article on DX-100 screen modulation at http://www.amwindow.org/tech/htm/scrnmod.htm You can also check my articles on peak-limiting compressors at http://www.amfone.net/AMPX/61.htm and http://www.amfone.net/AMPX/issue_number_79.htm Bacon, WA3WDR - Original Message - From: "Edward B Richards" <[EMAIL PROTECTED]> To: Sent: Wednesday, April 14, 2004 8:03 PM Subject: [AMRadio] Modulation Question > Hi Guys; > > I am new to this list so please forgive me if my questions are dumb or > redundant. I just rebuilt a much abused Heathkit DX-100B. As far as I can > tell it is operating OK into a dummy load. I have not put it on the air > yet. For one thing, I don't have a 75 meter antenna up yet. I have a > mobile ant I will install as soon as I have time. I do have a MFJ G5RV jr > that is good for 40 meters and higher. I have not heard any AM on > anything but 75 meters. Is there activity on 40 and / or 20 meters? > > I modified a scope to serve as a modulation monitor. I noticed 2 things > that puzzle me. > > 1. It is hard to tell modulation percent with voice as the waveform keeps > changing and unless I use a sine wave I can't sync it to get a good > envelope pattern. Any trick to this? > > 2. Using the mod mon I see that it is very easy to over-modulate. If I > keep the modulation down so I don't see short bright lines in the center > of the screen (carrier disappearing, I think) , the average modulation is > around 50% except for occasional peaks. Is this normal? would a > compression amplifier help? Thank you. > > 73, Ed Richards K6UUZ > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio >
Re: [AMRadio] Need suggestions on cleaning roller inductors.
People have had good results putting big items such as rotary inducrtors and bread-slicer capacitors into a dishwasher, and using regular dishwasher detergent. But don't do this with iron stuff like DC-power inductors and power transformers!!! Or tubes, either... the thrashing can be violent and might break the filaments, if not the glass. Clean tubes gently by hand with very mild soap or something. Bacon, WA3WDR - Original Message - From: "Mark Foltarz" <[EMAIL PROTECTED]> To: Sent: Thursday, June 17, 2004 1:27 AM Subject: [AMRadio] Need suggestions on cleaning roller inductors. > Trying like heck to get this TBW ready for field day weekend. > > I seriously doubt this transmitter has seen power in at least 40 years. > > It has two roller inductors that are plenty funky with oxidation. > > Any suggestions on cleaning them? > > tnx > > de KA4JVY > > Mark > > > > > __ > Do you Yahoo!? > Read only the mail you want - Yahoo! Mail SpamGuard. > http://promotions.yahoo.com/new_mail > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio
Re: [AMRadio] RE: Pix of BPL hardware on utility poles in Cincinnati
Heck, I thought we were all Radio Hobbits! - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Saturday, July 24, 2004 10:21 PM Subject: Re: [AMRadio] RE: Pix of BPL hardware on utility poles in Cincinnati > [EMAIL PROTECTED] writes: > > > radio hobbist > > Sorry - "radio hobbyist". > > Steve > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] filament voltages
The theory that I have seen holds that the cathode of a tube is protected against ion bombardment by the electrons it emits. When the emission capability of the tube is not exceeded, the cathode tries to emit too many electrons, but they have nowhere to go, so they cluster around the cathode and bounce around. Positive ions from gas in the tube are repelled from the plate and screen, and they accelerate toward the cathode - but they encounter this cloud of electrons, and they tend to hit the cloud and dissipate, rather than hitting the cathode and damaging it. But, if the emission capability of the cathode is exceeded, due to excessive current peaks or low emission due to age or low filament voltage, then the protective cloud of electrons is pulled away (the cathode can not replenish it), and the stray ions can then smash into the cathode, and do damage to it. And when the emission capability is exceeded, it usually means that the plate voltage is high during the period in the signal cycle when the emission limit is reached and exceeded (the tube can not pull the plate voltage down enough)... and this means that the ions have more voltage force accelerating them, and they hit the cathode harder. Bad news. So, too low of a filament voltage reduces the amount of current that can safely be handled by a tube, and if we do not observe the reduced limits, we can damage the tube. In my opinion, oxide cathodes are much more sensitive to this ion damage than thoriated-tungsten filamentary cathodes. I have read that non-thoriated tungsten filaments are even more resistant to ion damage than thoriated tungsten filaments. Bacon, WA3WDR - Original Message - From: "Donald Chester" <[EMAIL PROTECTED]> To: Sent: Monday, August 16, 2004 3:16 PM Subject: RE: [AMRadio] filament voltages > > > >A while back, you said something about running too little voltage on the > >older > >big jugs, like 833's, 250THs, 4-1000's, etc... > >Of course, we know that running voltages that are too high will kill the > >life > >expectancy of the tube, by why is running too little voltage bad for the > >tube, > >if it's developing full emmission at a lower voltage? > > I think low voltage would be ok as long as you are not exceeding the current > rating of the tube, starving the filament emission by running too low > filamrnt voltage, or exceeding the rated plate dissipation. > > Don k4kyv > > _ > Is your PC infected? Get a FREE online computer virus scan from McAfee® > Security. http://clinic.mcafee.com/clinic/ibuy/campaign.asp?cid=3963 > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net >
Re: [AMRadio] filament voltages
Hi Geoff, I don't know, exactly, and I am not familiar with the 250TH at all. I'll look at the tube specs later when I have some time, but I will only be able to guess where to set the filament voltage. But wow, that is a lot of reduction, you are talking a 20% reduction there... the resistance of a cooler filament will be lower than a hot one, so the current may only be reduced by 10%, and therefore the heat reduced by like 28%... still, the emission temperature will be down quite a bit... but if you do not see anything drop until you get to 3.5V, then 4V *may* be ok. Is this a modulated stage? If so, watch the positive peaks closely. And I would really worry about tuning up, where you might get serious current surges if you slip up. Maybe tune up with full filament voltage, and drop back afterwards? There's a point... positive peaks, higher plate voltage and simultaneous higher current.. that's a place to really watch out. But if you see no flattening even with a slight further reduction in filament voltage, with all other conditions the same, then that argues that you have an emission reserve, which protects the cathode. Does it protect the cathode as much? I don't know. Probably, if there is enough reserve. The whole point is to extend the emission life of the tube. I think advanced practice used to be to start out with a new tube using reduced filament voltage, maybe 5-10% low, and raise the filament voltage over the months and years as needed, as emission gradually fell. If any negative impact exists for the reduced filament voltage, it should be offset by the reduced overheat-breakdown effects, so that the net result will be an improvement in lifespan for the tube. It is difficult to determine where the exact point of emission saturation occurs. Also, transient conditions exist. The lower plate voltage should reduce the damage from emission-limited flattening that happens, but some damage will still occur. In an AM transmitter, you will see emission-limited flattening first on positive peaks. In a modulator peak flattening. In the modulator, look at the peaks of low frequency waves, below 200Hz. The finite transformer inductance causes this to be a higher current test. Flattening may start out soft... but cathode damage is cumulative... so don't tolerate *any* flattening unless you are positive that it is from voltage limiting, and not emission current limiting. A DC coupled scope may be able to show you this.. but in the RF amp, it will not be easy. You would have to build in a fast, high voltage sensing probe of some sort, and watch the instantaneous rf voltage on the plate. Line voltage fluctuations may surprise you. You may want to use a constant-voltage transformer or some regulated arrangement for the filament suppply. Maybe you should try 4.5V instead of 4V. I can only guess. Operating with lower plate voltage and lower cathode current will help. Be extra careful of the tube, because its cathode will have less reserve emission at the reduced filament voltage. Bacon, WA3WDR Geoff/W5OMR wrote: > > > The theory that I have seen holds that the cathode of a tube is > > protected against ion bombardment by the electrons it emits. When > > the emission capability of the tube is not exceeded, the cathode > > tries to emit too many electrons, but they have nowhere to go, so > > they cluster around the cathode and bounce around. Positive ions > > from gas in the tube are repelled from the plate and screen, and > > they accelerate toward the cathode - but they encounter this cloud > > of electrons, and they tend to hit the cloud and dissipate, rather > > than hitting the cathode and damaging it. > > > > But, if the emission capability of the cathode is exceeded, due to > > excessive current peaks or low emission due to age or low filament > > voltage, then the protective cloud of electrons is pulled away (the > > cathode can not replenish it), and the stray ions can then smash > > into the cathode, and do damage to it. And when the emission > > capability is exceeded, it usually means that the plate voltage is > > high during the period in the signal cycle when the emission limit > > is reached and exceeded (the tube can not pull the plate voltage > > down enough)... and this means that the ions have more voltage force > > accelerating them, and they hit the cathode harder. Bad news. > > > > So, too low of a filament voltage reduces the amount of current that > > can safely be handled by a tube, and if we do not observe the > > reduced limits, we can damage the tube. > > > > In my opinion, oxide cathodes are much more sensitive to this ion > > damage than thoriated-tungsten filamentary cathodes. I have read > > that non-thoriated tungsten filaments are even more resistant to ion > > damage than thoriated tungsten filaments. > > This is great, Bacon. What I was looking for. > > So, with my tubes not showing a reducti
Re: [AMRadio] filament voltages
Geoff, I looked at the 250TH specs, but I really can't make a solid judgement on acceptable filament voltage at reduced specs for long life. Generally I would be conservative; where you might reduce filament voltage a great deal, I recommed that you only reduce it slightly. Emission falls off very rapidly with reduction in filament voltage, and a small reduction probably has a large effect on tube life. I really can't specify how much you can safely reduce filament voltage, but with thoriated-tungsten filamentary cathode tubes, I would recommend that you don't reduce operating filament voltage more than 10% from spec. And make sure your socket connections are clean, etc. Ref: http://www.bext.com/filament.htm Ref: http://groups.google.com/groups?q=%22reduced+filament+voltage%22&hl=en&lr=&ie=UTF-8&safe=off&selm=3kp9s8%24o68%40indy-backup.indy.net&rnum=9 Some recommend not reducing filament voltage on large oxide-cathode tubes such as the 8877, etc. Ref: http://www.w8ji.com/vacuum_tubes_and_vaccum_tube_failures.htm Others claim remarkable improvements from filament voltage reduction. Ref: http://www.broadcast.harris.com/ support/kb/supportdocs.asp?fid=1050 (Note: I believe the 4CX2 is an oxide-cathode tube.) Other factors probably have as much effect on tube life. Excess current, of course, or operating before full emission temperature is reached, and thermal shock at turn-on. ref: http://lists.contesting.com/archives/html/Amps/2001-06/msg00213.html Burn-in: cook long-unused tubes at rated filament power for 100-200 hours. The idea is to allow the "getter" elements to absorb gas that has leaked into the tube or out of the materials in the tube. In tube operation, gas becomes ions which attack the cathode. Ref: http://www.rfparts.com/tubeapp.html Filament and cathode structures do not like thermal shock. The sudden application of filament voltage to a cold filament is a significant shock, because the resistance of a cold filament is much lower than its resistance when it is hot. A gradual application of filament power is best. This can be done with a resistor in series with the filament transformer primary, a small filament transformer that overloads at turn-on, etc. Filament voltage regulation is a good idea. Ref: http://www.vt52.com/diy/tips/tt_filaments.pdf But, be careful not to make the turn-on shock situation worse. Basically, I suggest one or two big constant-voltage transformers and a few small filament transformers, possibly with a series resistance of a few ohms in their primary circuits. The little transformers will overload on turn-on, limiting thermal shock to the tubes, yet the system will maintain operating filament voltage nicely, over a wide range of mains supply voltage. Then you can tweak the filament voltage to extend emission life, and the voltages will stay put, and turn on will be gentle. The gentler, the better. Bacon, WA3WDR
Re: [AMRadio] filament voltages (oops, Harris link fixed)
Geoff, I looked at the 250TH specs, but I really can't make a solid judgement on acceptable filament voltage at reduced specs for long life. Generally I would be conservative; where you might reduce filament voltage a great deal, I recommed that you only reduce it slightly. Emission falls off very rapidly with reduction in filament voltage, and a small reduction probably has a large effect on tube life. I really can't specify how much you can safely reduce filament voltage, but with thoriated-tungsten filamentary cathode tubes, I would recommend that you don't reduce operating filament voltage more than 10% from spec. And make sure your socket connections are clean, etc. Ref: http://www.bext.com/filament.htm Ref: http://groups.google.com/groups?q=%22reduced+filament+voltage%22&hl=en&lr=&ie=UTF-8&safe=off&selm=3kp9s8%24o68%40indy-backup.indy.net&rnum=9 Some recommend not reducing filament voltage on large oxide-cathode tubes such as the 8877, etc. Ref: http://www.w8ji.com/vacuum_tubes_and_vaccum_tube_failures.htm Others claim remarkable improvements from filament voltage reduction. Ref: http://www.broadcast.harris.com/support/kb/supportdocs.asp?fid=1050 (Note: I believe the 4CX2 is an oxide-cathode tube.) Other factors probably have as much effect on tube life. Excess current, of course, or operating before full emission temperature is reached, and thermal shock at turn-on. ref: http://lists.contesting.com/archives/html/Amps/2001-06/msg00213.html Burn-in: cook long-unused tubes at rated filament power for 100-200 hours. The idea is to allow the "getter" elements to absorb gas that has leaked into the tube or out of the materials in the tube. In tube operation, gas becomes ions which attack the cathode. Ref: http://www.rfparts.com/tubeapp.html Filament and cathode structures do not like thermal shock. The sudden application of filament voltage to a cold filament is a significant shock, because the resistance of a cold filament is much lower than its resistance when it is hot. A gradual application of filament power is best. This can be done with a resistor in series with the filament transformer primary, a small filament transformer that overloads at turn-on, etc. Filament voltage regulation is a good idea. Ref: http://www.vt52.com/diy/tips/tt_filaments.pdf But, be careful not to make the turn-on shock situation worse. Basically, I suggest one or two big constant-voltage transformers and a few small filament transformers, possibly with a series resistance of a few ohms in their primary circuits. The little transformers will overload on turn-on, limiting thermal shock to the tubes, yet the system will maintain operating filament voltage nicely, over a wide range of mains supply voltage. Then you can tweak the filament voltage to extend emission life, and the voltages will stay put, and turn on will be gentle. The gentler, the better. Bacon, WA3WDR - Original Message - From: "Geoff/W5OMR" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Monday, August 16, 2004 4:54 PM Subject: Re: [AMRadio] filament voltages > > > > The theory that I have seen holds that the cathode of a tube is > > protected against ion bombardment by the electrons it emits. When > > the emission capability of the tube is not exceeded, the cathode > > tries to emit too many electrons, but they have nowhere to go, so > > they cluster around the cathode and bounce around. Positive ions > > from gas in the tube are repelled from the plate and screen, and > > they accelerate toward the cathode - but they encounter this cloud > > of electrons, and they tend to hit the cloud and dissipate, rather > > than hitting the cathode and damaging it. > > > > But, if the emission capability of the cathode is exceeded, due to > > excessive current peaks or low emission due to age or low filament > > voltage, then the protective cloud of electrons is pulled away (the > > cathode can not replenish it), and the stray ions can then smash > > into the cathode, and do damage to it. And when the emission > > capability is exceeded, it usually means that the plate voltage is > > high during the period in the signal cycle when the emission limit > > is reached and exceeded (the tube can not pull the plate voltage > > down enough)... and this means that the ions have more voltage force > > accelerating them, and they hit the cathode harder. Bad news. > > > > So, too low of a filament voltage reduces the amount of current that > > can safely be handled by a tube, and if we do not observe the > > reduced limits, we can damage the tube. > > > > In my opinion, oxide cathodes are much more sensitive to this ion > > damage than thoriated-tungsten filamentary cathodes. I have read > > that non-thoriated tungsten filaments are even more resistant to ion > > damage than thoriated tungsten filaments. > > This is great, Bacon. What I was looking for. > > So, with my tubes not showing a reduction of emission until 3.5v is > real
Re: [AMRadio] B&W 5100B Modulation Update
Hi Tom, The A-3894 rating was 120W, the A-3893 rating was 60W. I am not sure what the power rating of the 3891 is. I'll assume it is good for 60W or more. What kind of current is the modulator drawing? A mod transformer with some shorted turns could cause the modulator current to be very high for a moderate percentage of modulation. The 600 volt B+ line could be pulling down because of this. It's quite common for an old mod transformer to be shorted and draw way too much current, and not be able to fully modulate the transmitter anyway. It could also be mismatched in such a way as to show a very low impedance to the modulator tubes, resulting in high mod current. If you disconnect the transformer and put 6.3VAC from plate to plate, you should see about 3 to 6VAC on the output side. If you are in doubt as to the tap configuration, measure the voltages and write it all down. Look for the highest voltages... connect the full windings, and try again, etc. If a mod transformer has split windings, make sure you hook them up in the proper polarity. Measure secondary voltage with 6.3VAC across the whole primary, and then measure secondary voltage with the 6.3VAC from CT to either end. You should get twice as much secondary output voltage with the 6.3V from CT to one end. If the secondary winding is split, make sure you see two times as much voltage from end-to-end of the secondary as you see from the CT to either end. Ultimately, you want a full-primary to secondary voltage ratio between 2:1 and 1:1. One winding will usually have more turns than the other. Generally you want the largest winding on the primary side, and the smaller winding on the secondary side (although this is not true for ultra-modulation). I have done best to use the full primary, and experiment with taps on the secondary. 2:1 voltage is 4:1 impedance. 1:1 voltage is 1:1 impedance. As KYV Don pointed out, the lower this ratio, the more modulation you will get, but the lower your modulator load impedance will be, and therefore the higher the modulator current will be for a given output power. 4:1 impedance won't give you 100% mod, while 1:1 could give you about 150% if the tubes are up to it. Typical commercial amateur transmitters used about a 3:1 or 4:1 impedance ratio so the modulation would voltage-limit at about 100%. That would be a voltage ratio of about 1.7:1 to 2:1. So if you put 6.3VAC on the full primary, you should get about 3.5V on the secondary. But that's just a starting point - when you get it all together, you probably want more like 6V on the secondary in this test, which ought to give you about 150% modulation capability. If you know the transformer is OK, you can put 120V AC on it and measure more easily, but 120V is dangerous if you may be connected to the wrong taps, etc. If your taps seem ok, but mod percentage is low, try 120VAC through a 25 watt light bulb to the full primary, with no load on the secondary. If the bulb lights up, you have a shorted transformer. Bacon, WA3WDR - Original Message - From: "Tom Elmore" <[EMAIL PROTECTED]> To: Sent: Wednesday, October 13, 2004 12:34 PM Subject: [AMRadio] B&W 5100B Modulation Update > Now that I have had some time to troubleshoot the B&W 5100B modulation here > is what I found. The B+ is around 600 volts with no modulation and I as > start to modulate and watch the scope when it reaches about 50% modulation > the B+ drops from 600 to around 400 volts. I changed the final and > modulator 6146 tubes and see the same results. The original modulation > transformer has been replaced with a Chicago Standard Transformer > Corporation # A-3891. When I remove B+ to the final's and terminate the > modulation secondary into a resistive load of about 6k ohms I still see a > significant drop in B+ as I start to bring modulation up. I don't have the > original mod transformer and the manual I have doesn't say what the > impedance should be. I have tried various other tap settings on the > transformer secondary and don't see much of an improvement in reducing the > amount of voltage drop. I wonder if it is possible that this mod transformer > just will not work with this unit. Anyone have experience with mod > transformers using 6146's as finals and modulators? > > Thank You > Tom Elmore KA1NVZ > Anchorage Alaska > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net >
Re: [AMRadio] B&W 5100B Modulation Update
Tom - if that's an A-3891, it isn't enough for a pair of 6146s. It's rated for 15 watts as I feared. http://www.amwindow.org/tech/htm/modtran/stancor/stancor.htm (Stancor and Chicago Standard appear to be the same company) But if it's really an A-3894 with worn paint, then you may be in luck. Bacon, WA3WDR - Original Message - From: "Tom Elmore" <[EMAIL PROTECTED]> To: Sent: Wednesday, October 13, 2004 12:34 PM Subject: [AMRadio] B&W 5100B Modulation Update > Now that I have had some time to troubleshoot the B&W 5100B modulation here > is what I found. The B+ is around 600 volts with no modulation and I as > start to modulate and watch the scope when it reaches about 50% modulation > the B+ drops from 600 to around 400 volts. I changed the final and > modulator 6146 tubes and see the same results. The original modulation > transformer has been replaced with a Chicago Standard Transformer > Corporation # A-3891. When I remove B+ to the final's and terminate the > modulation secondary into a resistive load of about 6k ohms I still see a > significant drop in B+ as I start to bring modulation up. I don't have the > original mod transformer and the manual I have doesn't say what the > impedance should be. I have tried various other tap settings on the > transformer secondary and don't see much of an improvement in reducing the > amount of voltage drop. I wonder if it is possible that this mod transformer > just will not work with this unit. Anyone have experience with mod > transformers using 6146's as finals and modulators? > > Thank You > Tom Elmore KA1NVZ > Anchorage Alaska > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net >
Re: [AMRadio] Re: B&W 5100B Audio Mods
Tom, a 6146 needs its screen modulated along with its plate, or it won't modulate well at all. If your transmitter provides screen voltage to the 6146 output stage from another source, it needs some kind of modulation. Somewhere around 60% mod on the screen is enough. Sometimes this is done with a separate winding on the mod transformer (which you don't have with the A-3894). If screen voltage comes from a lower voltage supply, you could get self-modulation using about 150V through a choke of about 50 henries, to give around 20K impedance at the low frequency end. The screen draws less current at higher plate voltages and more current at low plate voltages, so an impedance in series with the screen causes self modulation. Surprisingly, the screen tends to modulate itself by about the needed amount despite the varying impedance of the choke over frequency. In my Viking II, I used a 20K resistor from unmodulated B+ (600V), and the screen self-modulated pretty well. See "The Self-Modulated Screen" in AM Press/Exchange issue 98 ( http://www.amfone.net/AMPX/98.htm ). Also check "Class C Optimization for Ultra Low Distortion" by WA1KNX, in AM Press/Exchange issue 71 ( http://www.amfone.net/AMPX/71.htm ). Maybe you could put the screen dropping resistor to a tap on the mod transformer secondary. But, if the 5100 uses a low voltage screen supply and a series choke, you would need to add a clamp tube if you switched to the dropping-resistor design. Maybe you could whip up a screen co-modulator that would put out 150VDC with an adjustable amount of modulation, that tracked the modulation in the plate voltage. Then you could experiment with different amounts of screen modulation. Bacon, WA3WDR - Original Message - From: "Tom Elmore" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Thursday, October 21, 2004 8:27 PM Subject: Re: [AMRadio] Re: B&W 5100B Audio Mods > The unit I have has a separate B+ supply for the screens. So would this be > self-modulating then? > > -Tom > - Original Message - > From: "ne1s" <[EMAIL PROTECTED]> > To: "Discussion of AM Radio" > Sent: Wednesday, October 20, 2004 8:56 AM > Subject: [AMRadio] Re: B&W 5100B Audio Mods > > > > i am not familiar with the 5100B, but I would be VERY surprised if the > > screens weren't modulated as well as the plates - it is absolutely > necessary > > to achieve 100% modulation of tetrode, pentode, or beam-power calss C RF > > stages. This is usually done with this class of transmitters (~100W > > commercially-manufactured ham AM rigs)with a screen droping resistor from > > the modulated plate supply. It can also be done with a dropping resistor > > from the unmodulated B+, or an audio choke from a voltage source equal to > > the desired screen voltage; in these cases, the screens self-modulate. > > > > GL, > > -Larry/NE1S > > > > Tom Elmore writes: > > > > > Does, anyone know of a source for audio mods for the B&W 5100B > > > transmitter. I wonder if anyone has tried to modulate the screens in > > > addition to the plate of the finals. It appears the screens use a > different > > > power supply than the plates of the finals. > > > > > > Thank You > > > Tom Elmore KA1NVZ > > > Anchorage Alaska > > > > > > __ > > > AMRadio mailing list > > > Home: http://mailman.qth.net/mailman/listinfo/amradio > > > Help: http://mailman.qth.net/mmfaq.html > > > Post: mailto:AMRadio@mailman.qth.net > > > > __ > > AMRadio mailing list > > Home: http://mailman.qth.net/mailman/listinfo/amradio > > Help: http://mailman.qth.net/mmfaq.html > > Post: mailto:AMRadio@mailman.qth.net > > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > From [EMAIL PROTECTED] Fri Oct 22 07:32:38 2004 Return-Path: <[EMAIL PROTECTED]> Delivered-To: amradio@mailman.qth.net Received: from smtp810.mail.sc5.yahoo.com (smtp810.mail.sc5.yahoo.com [66.163.170.80]) by mailman.qth.net (Postfix) with SMTP id 7043A859BF8 for ; Fri, 22 Oct 2004 07:32:33 -0400 (EDT) Received: from unknown (HELO candela) ([EMAIL PROTECTED]@68.91.195.197 with login) by smtp810.mail.sc5.yahoo.com with SMTP; 22 Oct 2004 11:31:50 - From: "Jim candela" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Subject: RE: [AMRadio] The 6L6 is nearly 69 years young 1936-2004! Date: Fri, 22 Oct 2004 06:31:49 -0500 Message-ID: <[EMAIL PROTECTED]> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) In-reply-to: <[EMAIL PROTECTED]> X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1
[AMRadio] BC669
Anyone out there with a PS they want to part with??? Just picked one up in great shape...It has the E on the front not the H as most of them I have seen...Any comments on this ole timer is appreciated. Best 73's Bob W1PE Mesquite, TX 75149 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.797 / Virus Database: 541 - Release Date: 11/15/04
[AMRadio] AF67/68
I have a really great AF68 working wonderful...Only thing left to do is find 2 knobs with the chrome insert or find chrome inserts...The bandswitch knob and the mike gain knobs are the two...Will buy or trade for two...Any out there??? Thanks all Very Best 73's Bob Peters-W1PE ARRL ASM, President QCWA Chapter 41 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.799 / Virus Database: 543 - Release Date: 11/19/04
[AMRadio] ART-13 and Power Supply
Have an ART-13 and PS F/S...Is on the air now at my buddy's house..Has original power cable and connector. The Modulator Speech amp has been modified. Best mike used on this so far is a D104 amplified. Have used a Behringer Mixer as well with a Heil Goldline and sounds great. Price is $600.00 picked up in the Dallas area or can ship. The PS is big and heavy and on roll around casters. Needs a good home folks...Can make a sched most anytime... By the way auto tune works great!!! Very Best 73's Bob Peters-W1PE ARRL ASM, President QCWA Chapter 41 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.799 / Virus Database: 543 - Release Date: 11/19/04
Re: [AMRadio] 3-500Z vs 4-400A
Hi Pat, The 20K resistor idea was published in an old article on getting 120 watts from a pair of 807s, but I have been told it really didn't produce that much power, it did some really odd things at low audio levels, and it really didn't sound good. The idea about tying the control grid and screen of a 4-400 together and using it as a triode might be better, but I suspect that the 3-500 will be a better triode than a kludged 4-400. Tying the screen of a 4-400 to the plate will *drastically* reduce plate voltage limits, and plate current will be much lower at acceptable grid potentials (instantaneous E-grid *below* instantaneous E-plate) - so it would be impractical, because the power output capability would be massively reduced. To do ultra-linear right would require a separate, center-tapped screen winding on the mod transformer. I am in favor of the 4-400, but with active screen drive to improve linearity. Some kind of circuit could take instantaneous control-grid drive and produce a corrective pre-distortion to the screen voltage, aimed at making the grid-plate transfer as linear as possible, and making overload graceful. With lower voltage tubes such as the 6L6, 807 and 8417, it is actually possible to accomplish this with simple resistors in series with the screens. But the big, higher voltage tubes have so much secondary screen emission that such resistance can not be tolerated. So with higher voltage tubes, a more complex active screen control is required. But when the smoke clears... you will have the output and gain of a tetrode, but with the linearity of a triode (or better). With decently designed feedback, you can have the source resistance of a triode as well. I've done it with 6L6s and 8417s. Some day maybe I'll try it on 4-400s or something. Bacon, WA3WDR
[AMRadio] Improving the linearity of multi-grid power tubes
I like the idea of full drive to screens and reduced drive to the control grid. It's something like the deal with 55% screen modulation with 100% plate modulation. And the bias idea... hmm, why not? Makes me think of trying a family of bias arrangements, to see which one is best, or to see if I can finish the tests, or even get the same results twice! My favorite arrangement now is class AB1 grounded-cathode beam tetrodes with control grid drive and essentially normal control and screen grid DC voltages, but slight *negative* audio applied to the screens. If series resistors are used to produce the negative screen audio, then damping is slightly higher, but the damping of this arrangement is not great unless feedback is used. Bacon, WA3WDR - Original Message - From: <[EMAIL PROTECTED]> To: Sent: Sunday, December 12, 2004 2:04 PM Subject: [AMRadio] (no subject) > Hi Bob: > I thought the 20K resistor trick was invented by RCA. I seem to remember (of course these days I forget a lot) an article in a RCA manual about the experiments done by RCA prior to the 6L6, where the 20K resistor was to get rid of the distortion in Class B Zero bias triode operation. I have gotten a lot of power from 1625s doing this. For intermittent amateur service I have run 1200 Volts on them till the goats came home, and 1800 volts for a few moments of "FOURRRS". Of course at 750 volts, or was it 800 volts, I am not sure of the exact output but I believe with the perfect match and new tubes that they would do 120 watts as RCA said. As for distortion, at the rated output, wll, I believe in inverse feed back in all cases, if possible, HIHI. > > I did the bit on 813s and found the best was full drive to the screens and reduce drive the grid via another XFMR. But I placed full screen voltage and grid bias on both while driving both screen and grid. It was a configuration I had never seen before and I don't know why I did it. (Because I could?) but it produced a lot of output at very low distortion with great damping. > > I love this experimental talk! > > John, WA5BXO > > -Original Message- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bob Bruhns > Sent: Sunday, December 12, 2004 11:04 AM > To: Discussion of AM Radio > Subject: Re: [AMRadio] 3-500Z vs 4-400A > > Hi Pat, > > The 20K resistor idea was published in an old article on getting 120 watts > from a pair of 807s, but I have been told it really didn't produce that much > power, it did some really odd things at low audio levels, and it really > didn't sound good. > > The idea about tying the control grid and screen of a 4-400 together and > using it as a triode might be better, but I suspect that the 3-500 will be a > better triode than a kludged 4-400. > > Tying the screen of a 4-400 to the plate will *drastically* reduce plate > voltage limits, and plate current will be much lower at acceptable grid > potentials (instantaneous E-grid *below* instantaneous E-plate) - so it > would be impractical, because the power output capability would be massively > reduced. To do ultra-linear right would require a separate, center-tapped > screen winding on the mod transformer. > > I am in favor of the 4-400, but with active screen drive to improve > linearity. Some kind of circuit could take instantaneous control-grid drive > and produce a corrective pre-distortion to the screen voltage, aimed at > making the grid-plate transfer as linear as possible, and making overload > graceful. > > With lower voltage tubes such as the 6L6, 807 and 8417, it is actually > possible to accomplish this with simple resistors in series with the > screens. But the big, higher voltage tubes have so much secondary screen > emission that such resistance can not be tolerated. So with higher voltage > tubes, a more complex active screen control is required. > > But when the smoke clears... you will have the output and gain of a tetrode, > but with the linearity of a triode (or better). With decently designed > feedback, you can have the source resistance of a triode as well. > > I've done it with 6L6s and 8417s. Some day maybe I'll try it on 4-400s or > something. > > Bacon, WA3WDR > > > > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net >
Re: [AMRadio] Rothman Modulation
I saw some stuff too... if I understood, Rothman and others are experimenting with FM on a room-temperature laser to get precise spectrographic readings from low-cost gear. Kind of scientific ham stuff. Bacon, WA3WDR - Original Message - From: "Geoff/W5OMR" <[EMAIL PROTECTED]> To: Sent: Wednesday, December 22, 2004 10:24 AM Subject: [AMRadio] Rothman Modulation > This is a new term, for me. So, a Googling I went. > > Not much information on Rothman Modulation, but there was some. > Perhaps someone else on here can add to this? > > 73 = Best Regards, > -Geoff/W5OMR > > -- > Article: 101889 of rec.radio.amateur.boatanchors > From: Edward Knobloch <[EMAIL PROTECTED]> > Subject: Re: Info needed on "Taylor Modulation" from the 50's. > References: <[EMAIL PROTECTED]> > Message-ID: <[EMAIL PROTECTED]> > Date: Fri, 22 Oct 2004 17:06:49 GMT > > Mike Baker <[EMAIL PROTECTED]> wrote: > > Hello to all. > > When I was a kid I recall reading something in an old CQ/73/QST > > magazine about a modulation method for AM called Tayor Modulation. It > > was sort of a precursor to controlled carrier and used a seperate > > modulator tube hooked up sort of in parallel to the final amp and > > usually was the same tube type. There was no modulation transformer > > like in typical class B High level modulation schemes. > > > Hi, Mike > > You are thinking of "Rothman Modulation" April 1952 CQ. > (Which I can't find). If I recall correctly, controlled > carrier screen voltage for the finals was derived from the rf output > carrier power. I remember a picture of an outboard box with a couple > of 6Y6 style tubes (perhaps it was a single 6Y6 and a rectifier tube), > modulating a pair of 813's. > > 73, > Ed Knobloch > --- > > and the reply was... > > --- > > Article: 101890 of rec.radio.amateur.boatanchors > From: "COLIN LAMB" <[EMAIL PROTECTED]> > References: <[EMAIL PROTECTED]> > <[EMAIL PROTECTED]> > Subject: Re: Info needed on "Taylor Modulation" from the 50's. > Message-ID: <[EMAIL PROTECTED]> > Date: Fri, 22 Oct 2004 18:05:19 GMT > > Hello Ed: > > My wife says I have so much crap I could not possibly find anything - but I > walked right to the shelf where the April 1952 CQ magazine was. > > You are therefore batting 1 for 3, since you got it right on the outboard > chassis, but wrong on the 6Y6 style tube. However, when you get to be our > age and have forgotten more circuits than the younger hams have ever read > about, that is not that bad. > > Anyway, there were two different circuits shown. A 100 watt mobile > modulator using a 6X4 rf rectifier with a 6SN7 modulator tube, and a fixed > station modulator for up to 1000 watts uisng an 80 rf rectifier, a 6SL7 > speech amp and a 6CD6 modulator tube. Since the 6CD6 tube has a plate cap, > it does not look like a 6Y6. The 6BQ6 and 6BG6 can also be used. > > I have a number of 6CD6 and 6BG6 tubes and never could figure out what to do > with them. This is the answer. Build dozens of Rothman modulators. > > I think later that year and into 1953, you could buy an "efficiency > Modulator" using this system. They claimed 70% efficiency, which was much > better than the 52% efficiency of high level plate modulation. > > And my wife thinks I cannot find things. Ha. > > 73, Colin K7FM > - > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net >
[AMRadio] BAMA Files
What do I need to do to be able to print manuals on the BAMA website? Do I need Netscape? Also, I am looking for a 575A HV Rectifier or the solid state plug-in diodes. Anyone have some to sell? I am in the process of converting a Collins 20V-3 for 75M. I was reading some of the "AM Window" discussions with a chuckle. Don't you realize that the biggest signal gets the frequency regardless of emission type. If a SSB station jumps on to an AM QSO, just turn off the AM rig and reach over and turn on that big linear and tell them to move. It doesn't do any good to argue with them on AM cuz they probably don't know how to switch their rice box to that mode. I'll give y'all a demo one of these evenings. Bob W6TR
Re: [AMRadio] You Won't Believe This
Just remember that when you put the meter in the cathode circuit it measured combined plate & screen current. Bob Macklin K5MYJ/7 Seattle, Wa. "REAL RADIOS GLOW IN THE DARK" - Original Message - From: "David Knepper" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Saturday, January 01, 2005 10:11 PM Subject: Re: [AMRadio] You Won't Believe This > John, thank you for this. > > Collins engineers did not adhere to safe operating practice when they placed > the 800 ma meter in the positive lead going to the R.F. choke. It should > have been in the negative lead as you suggested. > > > Dave, W3ST > Publisher of the Collins Journal > Secretary to the Collins Radio Association > www.collinsra.com > Nets: 3805 Khz, Monday/Wednesdays 8 PM EDST > 14250 Khz Saturday, 12 Noon EDST > > - Original Message - > From: "John Coleman, ARS WA5BXO" <[EMAIL PROTECTED]> > To: "'Discussion of AM Radio'" > Sent: Sunday, January 02, 2005 12:31 AM > Subject: RE: [AMRadio] You Won't Believe This > > > > I gather from the text about the HV meter and current meter that the > > current meter is above ground by 4000 Volts. I know that there are a > > lot of special mounting devices and hardware for this purpose but I > > still feel that it is a bad idea. I have always made sure that HV > > current metering was done in the current path that is close to ground > > potential. As a further precaution it is a good idea to put a 50 Volt > > or less avalanche diode across the meter in case it should become open. > > As for the defection phenomenon, it might even be possible that the > > continued HV on the meter has put permanent static charge in the > > molecular structure of the plastic. If this is the case then any > > connection even a ground on the meter would cause a deflection. In any > > case I would move the current metering circuit to the cathode circuit or > > the negative return of the power supply. Modification of initial > > circuitry sometimes requires lifting all the ground connections of > > filters and/or chokes to get a floating ground and then passing that > > through the meter for current readings. I my opinion it is well worth > > the effort. I always put chokes in the negative lead of power supplies > > as well. > > > > It is an interesting phenomenon though. So please let us know what you > > do find as the cause. > > > > 73, John, WA5BXO > > > > -Original Message- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of David Knepper > > Sent: Saturday, January 01, 2005 5:31 PM > > To: Discussion of AM Radio; Collins Mail List > > > > Subject: [AMRadio] You Won't Believe This > > > > That is right, only one lead connected and the meter is reading negative > > current. I switched this lead to the negative post and the meter still > > deflects downward past zero. > > > > > > > > __ > > AMRadio mailing list > > Home: http://mailman.qth.net/mailman/listinfo/amradio > > Help: http://mailman.qth.net/mmfaq.html > > Post: mailto:AMRadio@mailman.qth.net > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net >
[AMRadio] VFO for 20V-3
I am nearing completion of my 20V-3 for 75M and was wondering what VFO's are available that easily interface with the 20V-3. I was thinking of a Meissner but I can still remember its nick name the Signal Drifter when I used one with a pair of 813's back in 1956. I would appreciate the group's comments. Bob W6TR
Re: [AMRadio] VFO for 20V-3
When I got my 20V-3 the coil sets had already been modified for 75M by WA5MOE. He followed the directions in the conversion manual "published" by Bill Carns, N7OTQ. I have the manual and it says to remove the existing windings and replace with 22 turns of #24 silk covered coil wire. I don't think that silk covering is necessary. Plain old Formvar coated solid copper wire is fine. Do you have Bill's manual? I think he would send you one if you asked. Tnx for your input on the VFO. Bob - Original Message - From: "David Knepper" <[EMAIL PROTECTED]> To: "Bob Maser" <[EMAIL PROTECTED]> Sent: Thursday, January 06, 2005 7:45 PM Subject: Re: [AMRadio] VFO for 20V-3 Bob, I, too, own a 20V-3 and would be interested in knowing how you changed the two shielded coils to resonate on 75 meters. Will these same coils resonate on 160 meters. I finally, after much trial and error, got the buffer and driver coils to work on 160 meters. I had to remove wire from the coils. For a PTO,. I would recommend inserting it into the plate of the oscillator tube through a capacitor. You would pull out the oscillator tube, of course. Perhaps, a Heathkit VFO - being more common - would work. Thanks Dave, W3ST Publisher of the Collins Journal Secretary to the Collins Radio Association www.collinsra.com Nets: 3805 Khz, Monday/Wednesdays 8 PM EDST 14250 Khz Saturday, 12 Noon EDST - Original Message - From: "Bob Maser" <> To: "AMRadio" Sent: Thursday, January 06, 2005 9:37 PM Subject: [AMRadio] VFO for 20V-3 I am nearing completion of my 20V-3 for 75M and was wondering what VFO's are available that easily interface with the 20V-3. I was thinking of a Meissner but I can still remember its nick name the Signal Drifter when I used one with a pair of 813's back in 1956. I would appreciate the group's comments. Bob W6TR __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
[AMRadio] (no subject)
I'm presently converting a Gates BC-1H (and later a BC-1T) transmitter to 160, 75 and 40 meters. Using a HP 3320B frequency synthesizer as a VFO and a home brew MOSFET driver fed into the grids of the 807s. From there I'm modifying the 807 output tank with relays for 160-40. The final output (two 833's) will be tuned with the stock roller inductor along with a vac. variable. The synthesizer is accurate and drift free, I see alot of them on ebay for reasonable prices. Bob KG4OJZ (ex K1SUI) Transmitter Engineer WDBJ-TV-7
[AMRadio] AM Amps
Why not just use a coax Tee and dump half of the output power of the Ranger into a 50 ohm dummy load and the other half into the amp? Bob
[AMRadio] AM Amps
I wonder if I could drive my 3CX3000 Lineeaar with my Valiant. H. Bob
Re: [AMRadio] AM Amps
Nice amp! 670 watts dissipation, 1430 watts out means 1430 + 670 watts input, or 2100W input. (This agrees with the plate voltage and plate current.) Efficiency would be 1430/2100 = 0.681 or 68.1%, which is quite good for a linear amplifier at maximum output. In linear operation, an amplifier's efficiency is proportional to its output. At full power output, you get maximum efficiency. That means 1430 watts is the maximum output for the particular tuning adjustment of the amp. So an AM signal passed through this amplifier set up as described would produce positive peaks up to 1430 watts. For faithful reproduction of AM with 100% positive modulation, this would correspond to 1430/4 = 357.5 watts carrier. So somehow the driver power would have to be reduced for proper AM operation. Your mileage may vary. - Original Message - From: "James M. Walker" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Thursday, January 13, 2005 11:48 AM Subject: Re: [AMRadio] AM Amps > Hum, > 4-1000A G.G. amplifier, 3000 VDC plate, 700 MA Plate I, 500 MA > Grid I, with 125 Watts out of DX-100 running apprx 2100 W input and > dissipating 670 watts plate = approximately 1430 watts output! > > While the carrier level into 50 ohm dummy load is 1400 watts measured > and a really NICE orange glow! This is with a 200 cfm blower, air system > socket and chimney. > > Jim > WB2FCN > > - Original Message - > From: "Jim candela" <[EMAIL PROTECTED]> > To: "Discussion of AM Radio" > Sent: Wednesday, January 12, 2005 7:07 PM > Subject: RE: [AMRadio] AM Amps > > > > > > Darrell, > > > > That amp you built with the 4-1000 was a "killer" in more ways than one! > > Time for a confession.. > > > > Regards, > > Jim > > WD5JKO > > > > -Original Message- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] Behalf Of Darrell, WA5VGO > > Sent: Tuesday, January 11, 2005 6:04 PM > > To: Discussion of AM Radio > > Subject: Re: [AMRadio] AM Amps > > > > > > At 04:21 PM 1/11/2005 -0500, you wrote: > > > > >In a message dated 1/11/05 12:14:43 PM, [EMAIL PROTECTED] writes: > > > > > > > > > > well all I can say is it works.. works well as a matter of fact, and > has > > > > been for 6 years :) > > > > I typically run between 350 and 400 watts of carrier every day. It > looks > > > > great on the scope. Modulation envelope is perfect. 100% modulation. > In > > 6 > > > > years Ive only lost one tube, and I accidently broke that one. > > > > > > > > > > > > > >I have to agree with Gary. You're seeing 1600 watts PEP and 400W of > > carrier > > >OUT with a pair of GG 813s??? Does not compute! Just curious, are you > > >talking about 400W INPUT power to the linear under carrier only condx > > >maybe? If > > >so, this would work out to about 133W carrier OUT and each 813 > dissipating > > >about 133W which would make more sense. > > > > > >Dennis D. W7QHO > > >Glendale, CA > > > > > > I'm with Dennis and Gary. To run a linear amplifier at 375 watts of > carrier > > and 100% modulation, you will need around 800 watts of plate dissipation. > > For a short time a number of years ago, I tried running an AF-68 and a > > 4-1000A linear amplifier. I could never get more than around 450 watts of > > carrier and stay linearI didn't need a heater in the shack > > either. > > > > 73, > > Darrell, WA5VGO > > > > > > > > 73, > > Darrell, WA5VGO > > > > > > > > > > __ > > AMRadio mailing list > > Home: http://mailman.qth.net/mailman/listinfo/amradio > > Help: http://mailman.qth.net/mmfaq.html > > Post: mailto:AMRadio@mailman.qth.net > > > > -- > > No virus found in this incoming message. > > Checked by AVG Anti-Virus. > > Version: 7.0.300 / Virus Database: 265.6.10 - Release Date: 1/10/2005 > > > > -- > > No virus found in this outgoing message. > > Checked by AVG Anti-Virus. > > Version: 7.0.300 / Virus Database: 265.6.11 - Release Date: 1/12/2005 > > > > __ > > AMRadio mailing list > > Home: http://mailman.qth.net/mailman/listinfo/amradio > > Help: http://mailman.qth.net/mmfaq.html > > Post: mailto:AMRadio@mailman.qth.net > > > > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net >
Re: [AMRadio] AM Amps
Come to think of it - since it is a grounded grid amp, some of the driver power is appearing in the output, so actual efficiency is really a bit below 68%. Still quite good. The output AM carrier power ratio holds; for faithful reproduction of AM with 100% positive modulation, the carrier power will be 357.5 watts. - Original Message - From: "Bob Bruhns" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Friday, January 14, 2005 11:51 AM Subject: Re: [AMRadio] AM Amps > Nice amp! 670 watts dissipation, 1430 watts out means 1430 + 670 > watts input, or 2100W input. (This agrees with the plate voltage > and plate current.) Efficiency would be 1430/2100 = 0.681 or 68.1%, > which is quite good for a linear amplifier at maximum output. > > In linear operation, an amplifier's efficiency is proportional to > its output. At full power output, you get maximum efficiency. That > means 1430 watts is the maximum output for the particular tuning > adjustment of the amp. So an AM signal passed through this > amplifier set up as described would produce positive peaks up to > 1430 watts. For faithful reproduction of AM with 100% positive > modulation, this would correspond to 1430/4 = 357.5 watts carrier. > So somehow the driver power would have to be reduced for proper AM > operation. Your mileage may vary. > > > - Original Message - > From: "James M. Walker" <[EMAIL PROTECTED]> > To: "Discussion of AM Radio" > Sent: Thursday, January 13, 2005 11:48 AM > Subject: Re: [AMRadio] AM Amps > > > > Hum, > > 4-1000A G.G. amplifier, 3000 VDC plate, 700 MA Plate I, 500 MA > > Grid I, with 125 Watts out of DX-100 running apprx 2100 W input > and > > dissipating 670 watts plate = approximately 1430 watts output! > > > > While the carrier level into 50 ohm dummy load is 1400 watts > measured > > and a really NICE orange glow! This is with a 200 cfm blower, air > system > > socket and chimney. > > > > Jim > > WB2FCN > > > > - Original Message - > > From: "Jim candela" <[EMAIL PROTECTED]> > > To: "Discussion of AM Radio" > > Sent: Wednesday, January 12, 2005 7:07 PM > > Subject: RE: [AMRadio] AM Amps > > > > > > > > > > Darrell, > > > > > > That amp you built with the 4-1000 was a "killer" in more ways > than one! > > > Time for a confession.. > > > > > > Regards, > > > Jim > > > WD5JKO > > > > > > -Original Message- > > > From: [EMAIL PROTECTED] > > > [mailto:[EMAIL PROTECTED] Behalf Of Darrell, > WA5VGO > > > Sent: Tuesday, January 11, 2005 6:04 PM > > > To: Discussion of AM Radio > > > Subject: Re: [AMRadio] AM Amps > > > > > > > > > At 04:21 PM 1/11/2005 -0500, you wrote: > > > > > > >In a message dated 1/11/05 12:14:43 PM, > [EMAIL PROTECTED] writes: > > > > > > > > > > > > > well all I can say is it works.. works well as a matter of > fact, and > > has > > > > > been for 6 years :) > > > > > I typically run between 350 and 400 watts of carrier every > day. It > > looks > > > > > great on the scope. Modulation envelope is perfect. 100% > modulation. > > In > > > 6 > > > > > years Ive only lost one tube, and I accidently broke that > one. > > > > > > > > > > > > > > > > > >I have to agree with Gary. You're seeing 1600 watts PEP and > 400W of > > > carrier > > > >OUT with a pair of GG 813s??? Does not compute! Just > curious, are you > > > >talking about 400W INPUT power to the linear under carrier only > condx > > > >maybe? If > > > >so, this would work out to about 133W carrier OUT and each 813 > > dissipating > > > >about 133W which would make more sense. > > > > > > > >Dennis D. W7QHO > > > >Glendale, CA > > > > > > > > > I'm with Dennis and Gary. To run a linear amplifier at 375 watts > of > > carrier > > > and 100% modulation, you will need around 800 watts of plate > dissipation. > > > For a short time a number of years ago, I tried running an AF-68 > and a > > > 4-1000A linear amplifier. I could never get more than around 450 > watts of > > > carrier and stay linearI didn't need a heater in the > shack > > > either. > > > > > > 73, > > >
[AMRadio] 20V-3 Lamps
I am looking for a source of supply for the 230vac lamps used in the filament and plate indicators. Only one of mine functions, need at least one. Bob
Re: [AMRadio] 20V-3 Lamps
They are about 1-1/2" tall and have a screw-in base, kinda like the old Xmas tree lights but these run on 230vac. According to my 20V-3 manual, they have a GE part number 10S6/10-250, C-7A filament, S-6 bulb. Bob in Tampa, FL W6TR - Original Message - From: "CHRIS PAPAIOANNOU" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Friday, January 14, 2005 11:20 PM Subject: Re: [AMRadio] 20V-3 Lamps what kind of lamps are these 20v-3.I remember some lamps forgotten in my junkbox that i have no need of them. Chris SV1DAF. - Original Message - From: "Bob Maser" <[EMAIL PROTECTED]> To: "AMRadio" Sent: Saturday, January 15, 2005 6:30 AM Subject: [AMRadio] 20V-3 Lamps I am looking for a source of supply for the 230vac lamps used in the filament and plate indicators. Only one of mine functions, need at least one. Bob __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] 20V-3 Lamps
I tried that and you are right! I am going to check out a nearby electrical supply house tomorrow. If no luck, I'll try some of the places shown by the Google search. Thanks forthe tip. Bob 6TR - Original Message - From: "Clay Curtiss W7CE" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Saturday, January 15, 2005 12:21 AM Subject: Re: [AMRadio] 20V-3 Lamps Just go to Google and type in 10S6/10-250. You'll get links to several online suppliers of this bulb. Clay W7CE ----- Original Message - From: "Bob Maser" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Friday, January 14, 2005 10:07 PM Subject: Re: [AMRadio] 20V-3 Lamps They are about 1-1/2" tall and have a screw-in base, kinda like the old Xmas tree lights but these run on 230vac. According to my 20V-3 manual, they have a GE part number 10S6/10-250, C-7A filament, S-6 bulb. Bob in Tampa, FL W6TR - Original Message - From: "CHRIS PAPAIOANNOU" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Friday, January 14, 2005 11:20 PM Subject: Re: [AMRadio] 20V-3 Lamps > what kind of lamps are these 20v-3.I remember some lamps forgotten in > my > junkbox that i have no need of them. > Chris SV1DAF. > - Original Message - > From: "Bob Maser" <[EMAIL PROTECTED]> > To: "AMRadio" > Sent: Saturday, January 15, 2005 6:30 AM > Subject: [AMRadio] 20V-3 Lamps > > >> I am looking for a source of supply for the 230vac lamps used in the >> filament and plate indicators. Only one of mine functions, need at least >> one. >> >> Bob >> >> >> __ >> AMRadio mailing list >> Home: http://mailman.qth.net/mailman/listinfo/amradio >> Help: http://mailman.qth.net/mmfaq.html >> Post: mailto:AMRadio@mailman.qth.net >> > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] 20V-3 Lamps
Thanks Chris. Maybe I can work you on 75 on AM some evening. Bob - Original Message - From: "CHRIS PAPAIOANNOU" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Saturday, January 15, 2005 1:05 AM Subject: Re: [AMRadio] 20V-3 Lamps found some [EMAIL PROTECTED] not 230ac.It's not what you're looking for but anyway i see hr you allready found an end. Chris SV1DAF. ----- Original Message - From: "Bob Maser" <[EMAIL PROTECTED]> To: "Clay Curtiss W7CE" <[EMAIL PROTECTED]>; "Discussion of AM Radio" Sent: Saturday, January 15, 2005 8:41 AM Subject: Re: [AMRadio] 20V-3 Lamps I tried that and you are right! I am going to check out a nearby electrical supply house tomorrow. If no luck, I'll try some of the places shown by the Google search. Thanks forthe tip. Bob 6TR - Original Message - From: "Clay Curtiss W7CE" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Saturday, January 15, 2005 12:21 AM Subject: Re: [AMRadio] 20V-3 Lamps > Just go to Google and type in 10S6/10-250. You'll get links to several > online suppliers of this bulb. > > Clay W7CE > > - Original Message - > From: "Bob Maser" <[EMAIL PROTECTED]> > To: "Discussion of AM Radio" > Sent: Friday, January 14, 2005 10:07 PM > Subject: Re: [AMRadio] 20V-3 Lamps > > >> They are about 1-1/2" tall and have a screw-in base, kinda like the >> old > Xmas >> tree lights but these run on 230vac. According to my 20V-3 manual, they >> have a GE part number 10S6/10-250, C-7A filament, S-6 bulb. >> Bob in Tampa, FL W6TR >> - Original Message - >> From: "CHRIS PAPAIOANNOU" <[EMAIL PROTECTED]> >> To: "Discussion of AM Radio" >> Sent: Friday, January 14, 2005 11:20 PM >> Subject: Re: [AMRadio] 20V-3 Lamps >> >> >> > what kind of lamps are these 20v-3.I remember some lamps forgotten >> > in >> > my >> > junkbox that i have no need of them. >> > Chris SV1DAF. >> > - Original Message - >> > From: "Bob Maser" <[EMAIL PROTECTED]> >> > To: "AMRadio" >> > Sent: Saturday, January 15, 2005 6:30 AM >> > Subject: [AMRadio] 20V-3 Lamps >> > >> > >> >> I am looking for a source of supply for the 230vac lamps used in >> >> the >> >> filament and plate indicators. Only one of mine functions, need at > least >> >> one. >> >> >> >> Bob >> >> >> >> >> >> __ >> >> AMRadio mailing list >> >> Home: http://mailman.qth.net/mailman/listinfo/amradio >> >> Help: http://mailman.qth.net/mmfaq.html >> >> Post: mailto:AMRadio@mailman.qth.net >> >> >> > >> > __ >> > AMRadio mailing list >> > Home: http://mailman.qth.net/mailman/listinfo/amradio >> > Help: http://mailman.qth.net/mmfaq.html >> > Post: mailto:AMRadio@mailman.qth.net >> > >> >> >> __ >> AMRadio mailing list >> Home: http://mailman.qth.net/mailman/listinfo/amradio >> Help: http://mailman.qth.net/mmfaq.html >> Post: mailto:AMRadio@mailman.qth.net > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net > __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
Re: [AMRadio] 20V3 bulbs
I just got back from HD and Lowes and neither store carried a 230vac bulb. I guess I'll wait until Monday and go visit a electrical supply store. Thanks anyway. Bob W6TR - Original Message - From: "P Cour" <[EMAIL PROTECTED]> To: Sent: Saturday, January 15, 2005 11:07 AM Subject: [AMRadio] 20V3 bulbs Correction Bob, yours is the 20V3. Our friend Mike W8BAC recently put one of them on the air, on both 75 and 160 meters. Pretty "modern" looking rig, I must say, and goes well with any living room decor. I got a better image of that bulb blister pack. Print it out and take it with you. Abco was making that 240V version I mentioned too. http://www.netohio.com/wa3vjb/bub.jpg --- [EMAIL PROTECTED] wrote: Send AMRadio mailing list submissions to amradio@mailman.qth.net To subscribe or unsubscribe via the World Wide Web, visit http://mailman.qth.net/mailman/listinfo/amradio or, via email, send a message with subject or body 'help' to [EMAIL PROTECTED] You can reach the person managing the list at [EMAIL PROTECTED] When replying, please edit your Subject line so it is more specific than "Re: Contents of AMRadio digest..." Today's Topics: 1. Re: 20V-3 Lamps (CHRIS PAPAIOANNOU) -- Message: 1 Date: Sat, 15 Jan 2005 08:44:15 +0200 From: "CHRIS PAPAIOANNOU" <[EMAIL PROTECTED]> Subject: Re: [AMRadio] 20V-3 Lamps To: "Discussion of AM Radio" Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="Windows-1252" Bob i'd like it too!let's wait for any good openings or the triumphal return of the solar emissions. Chris SV1DAF. - Original Message - From: "Bob Maser" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Saturday, January 15, 2005 9:01 AM Subject: Re: [AMRadio] 20V-3 Lamps > Thanks Chris. Maybe I can work you on 75 on AM some evening. > Bob > - Original Message - > From: "CHRIS PAPAIOANNOU" <[EMAIL PROTECTED]> > To: "Discussion of AM Radio" > Sent: Saturday, January 15, 2005 1:05 AM > Subject: Re: [AMRadio] 20V-3 Lamps > > > > found some [EMAIL PROTECTED] not 230ac.It's not what you're looking for but > > anyway > > i see hr you allready found an end. > > Chris SV1DAF. > > - Original Message - > > From: "Bob Maser" <[EMAIL PROTECTED]> > > To: "Clay Curtiss W7CE" <[EMAIL PROTECTED]>; "Discussion of AM Radio" > > > > Sent: Saturday, January 15, 2005 8:41 AM > > Subject: Re: [AMRadio] 20V-3 Lamps > > > > > >> I tried that and you are right! I am going to check out a nearby > > electrical > >> supply house tomorrow. If no luck, I'll try some of the places shown by > > the > >> Google search. > >> Thanks forthe tip. > >> > >> Bob 6TR > >> - Original Message - > >> From: "Clay Curtiss W7CE" <[EMAIL PROTECTED]> > >> To: "Discussion of AM Radio" > >> Sent: Saturday, January 15, 2005 12:21 AM > >> Subject: Re: [AMRadio] 20V-3 Lamps > >> > >> > >> > Just go to Google and type in 10S6/10-250. You'll get links to several > >> > online suppliers of this bulb. > >> > > >> > Clay W7CE > >> > > >> > - Original Message - > >> > From: "Bob Maser" <[EMAIL PROTECTED]> > >> > To: "Discussion of AM Radio" > >> > Sent: Friday, January 14, 2005 10:07 PM > >> > Subject: Re: [AMRadio] 20V-3 Lamps > >> > > >> > > >> >> They are about 1-1/2" tall and have a screw-in base, kinda like the > >> >> old > >> > Xmas > >> >> tree lights but these run on 230vac. According to my 20V-3 manual, > > they > >> >> have a GE part number 10S6/10-250, C-7A filament, S-6 bulb. > >> >> Bob in Tampa, FL W6TR > >> >> - Original Message - > >> >> From: "CHRIS PAPAIOANNOU" <[EMAIL PROTECTED]> > >> >> To: "Discussion of AM Radio" > >> >> Sent: Friday, January 14, 2005 11:20 PM > >> >> Subject: Re: [AMRadio] 20V-3 Lamps > >> >> > >> >> > >> >> > what kind of lamps are these 20v-3.I remember some lamps forgotten > >> >> > in > >> >> > my > >> >> > junkbox that i have no need of them. > >> >> > Chris SV1DAF. > >> >&g
Re: [AMRadio] Physical Reality of Sidebands
I contend that we are synthesizing a double-sideband with carrier signal when we modulate amplitude by varying PA B+, or by other means. You can draw a graph of the carrier, upper sideband and lower sideband sine waves (of course you must make the relative timing/phase correct), and add them together, and the resulting composite signal will be identical to the modulated signal we produce with our modulated stage. Therefore I conclude that they are the same; that the sidebands exist, and that the carrier is continuous, even though the composite signal may vary from 0 to 2x the carrier level. - Original Message - From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]>; Sent: Sunday, January 16, 2005 4:12 PM Subject: Re: [AMRadio] Physical Reality of Sidebands > Sounds to me like the old question as to whether or not a tree falling in a > forest makes a crashing sound if there is no one around to hear it. In > answering such a question one has to draw a distinction > as to whether "sound" exists only as the reaction of the human auditory > system to pressure waves in the conducting medium (air in this case) or, do these > pressure waves themselves constitute "sound." Don seems to be saying > sidebands exist only exist as a "physical reality" when apprehended by a human > observer through the reactions of some kind of instrumentation (narrow receiver, > etc.).Seems like a philosophical rather than an engineering issue to me. > > Dennis D. W7QHO > Glendale, CA > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net >
Re: [AMRadio] Physical Reality of Sidebands
Indeed, 'tis a puzzlement. I can draw three continuous sine waves of apppropriate amplitude, frequency and phase, corresponding to carrier, upper sideband and lower sideband, and I can add them point by point, and I can duplicate a 100% modulated AM signal waveform as we understand it. I have to believe that this works backwards; if I make this waveform by modulating a carrier in an AM transmitter, then I am synthesizing the same continuous sine waves. It seems to me that an on-off sequence would only differ from the sine wave modulated condition in the complexity of the sideband spectrum. But in the real world, sometimes theory does not produce results. For example, if there was some FM audio subchannel modulating the on-off carrier, I would simply not be able to receive it while the transmitter was off, even if I was positive that the carrier was theoretically still present. So as Dennis asked on the amradio mailing list - if a tree falls in the forest, and nobody sees it or hears it... did it really fall? When I am receiving zero, I can only know that I am receiving zero. And if there is interference, I may not even be sure I am receiving zero! And as Don pointed out, there is the question of reality, and the appearance of reality. If I took the time scale to infinity, then if a carrier was EVER transmitted, even for only a second, I would have to say that it existed for all of time. That's ridiculous! I only think that because I am integrating over all time, and then generalizing. I guess it's off when it's off, and it's signalling us when it's on. So the question becomes, at what time scale do we stop seeing beat notes, and start seeing variations and on-off switching? Bacon, WA3WDR
Re: [AMRadio] Physical Reality of Sidebands
I am convinced that sidebands exist. But as for whether the carrier goes away at 100% negative modulation... How's this: a carrier should be considered to exist during the period when it has recently been detected, and we are actually receiving modulation from it. It should not be considered to exist when it is clearly not being generated. So in the example of an AM signal at the instant of 100% negative modulation, we should consider the zero to represent zero percent of the carrier, averaged over time during recent history. We can see that this will result in appropriate demodulation of the actual signal. But when the AM transmission is over, either after the end of a transmission, or after the end of a broadcast day, or in most cases if the signal fades out due to propagation, etc, we should consider the carrier not to be present. This gets a little tricky, because we can not really be certain (Don's Heisenberg Uncertainty Principle thought here) that the transmitter is not sending us a very, very long zero. But we can be pretty sure, pretty quick. A synchronous detector is a good flywheel that tracks the known carrier frequency and holds the reference for us during zeros and noise bursts. We set up a synchronous detector to detect the carrier and hold the reference for a short period of time. This works pretty well for the signals we actually transmit. Now take the example of a 1 KHz sinewave transmitted as double sideband suppressed carrier. You get pulses of alternating carrier polarity. During any given pulse, for about 500 microseconds at a time, you get an AM signal with a carrier, transmitting one half of a sine wave. When the pulse is over and the signal passes through zero, it goes negative and the next pulse appears - pretty much identical to the first pulse, but with reverse carrier polarity. You would not know the carrier polarity reversed except for your flywheel reference. But demodulating with the flywheel reference gives you the 1 KHz sinewave. It is evident to the observer that the flywheel reference was correct. With a very low modulating frequency, a DSBSC signal would just look like a fading carrier. The transmit frequency stability and the reference flywheel precision would have to be very high to determione that the carrier polarity had reversed. At some point this becomes irrelevant, because the transmission path varies in length, there is drift and phase noise in TX and RX, and the signal is not received well enough to know for sure that the carrier polarity flipped. (Uncertainty again.) And although with DSBSC we keep getting pulses of carrier, they keep reversing, and on average they balance out to zero. We accept that the carrier is suppressed, we don't hear a heterodyne where we would usually hear one, etc, yet we see the carrier dancing on the oscilloscope. But over the appropriate integration time, its frequent polarity reversals cause it to balance out to zero. For most real signals, a very long time base is inappropriate. In some cases though, such as slow synchronous CW, a long time base is appropriate. So the receiver time scale should be appropriate to the signal being sought. So it's a reality check issue. Surely a carrier was not transmitted for all time, just because it existed for less than a second at some point. But just as surely, the instant of 100% negative modulation should not be reproduced as a glitch. The application of the appropriate time scale is the key, and it is up to the listener to determine what happened. Bacon, WA3WDR
Re: [AMRadio] Physical Reality of Sidebands
Hi Gary, The carrier is not multiplied with the sideband frequencies to generate AM, it is multiplied with the baseband modulating frequency. In my example, three sine waves corresponding to a carrier and two sideband frequencies are added together to produce the AM signal, but a relatively low frequency is multiplied with the carrier in the AM transmitter to produce the carrier and sideband frequencies in the reverse example. Interestingly, if the AM signal, with or without carrier, is multiplied at the receiver with a regenerated carrier of proper frequency and phase, then the baseband modulating signal is recovered. In the transmitter, the multiplication occurs in the modulated stage. In plate-modulated AM, the carrier is multiplied by the plate voltage. Normalizing plate voltage to unity, it is multiplied by +1 without modulation. Modulation varies the B+, and therefore the multiplication factor. The normalized multiplication factor varies from 0 to +2 with 100% sine wave modulation. Bacon, WA3WDR
[AMRadio] Wanted: 20V-2 or -3
I am looking for a 20V-3 or -2 for a friend of mine who lives in the San Francisco area. He would be willing to travel to collect his prize. Bob W6TR
Re: [AMRadio] Wanted: 20V-2 or -3
Well, I already have a 20V-3 that's about ready for the smoke test. I am in the Tampa area. Can you send me some pics and tell me what comes with it and how much $$$ you are looking for? My friend will be visiting us here in Tampa early this summer. He will be pulling an Airstream trailer. Bob W6TR 813-643-3034 - Original Message - From: "Gary Blau" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Friday, January 21, 2005 9:05 PM Subject: Re: [AMRadio] Wanted: 20V-2 or -3 Hey Bob: This probably isn't what you had in mind, but I have a 20V-2 here waiting for conversion that it looks like I'm not going to be able to get to any time soon. Trouble is it's in Miami, FL! Does this help? 73, g Bob Maser wrote: I am looking for a 20V-3 or -2 for a friend of mine who lives in the San Francisco area. He would be willing to travel to collect his prize. Bob W6TR __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
[AMRadio] MORE INSANITY!
Unbuilt DX-60: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4675&item=5745646627&rd=1 Bob Macklin K5MYJ/7 Seattle, Wa. "REAL RADIOS GLOW IN THE DARK"
[AMRadio] Re: GB> MORE INSANITY!
I would rather use my money to buy a clean DOA and restore it. Bob Macklin K5MYJ/7 Seattle, Wa. "REAL RADIOS GLOW IN THE DARK" - Original Message - From: "Peter A Markavage" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Cc: Sent: Sunday, January 23, 2005 6:30 PM Subject: Re: GB> MORE INSANITY! > Look at the current high bidder's history. Two of the last three things > he bought were unbuilt kits. > Maybe he will put them up on a shelf and stare at them. > > Pete, wa2cwa > > On Sun, 23 Jan 2005 15:43:58 -0800 "Bob Macklin" <[EMAIL PROTECTED]> > writes: > > Unbuilt DX-60: > > > > > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=4675&item=57456466 > 27&rd=1 > > > > Bob Macklin > > K5MYJ/7 > > Seattle, Wa. > > > > "REAL RADIOS GLOW IN THE DARK" > > > > > > > > >
[AMRadio] Stealth Antennas?
I live in a senior apartment where I CANNOT have an outdoor antenna. So I
have a wire around the wall at the base of the ceiling. It is currently 1/4W
40M antenna.
I did buy the ARRL book on "Stealh Radio".
HF mobile antennas use loading coils to make the antenna look longer. The
better one us a coil in the center of the antenna.
Some apartment antennas are nothing but a mobile whip with a base loading
coil. Why BASE LOADING?
But the real question is why not use a loading coil at the center of a long
wire or dipole to make it look longer? The original Heath Antenna Tuner was
just a loading coil("L" section) that allowed use of a SHORT wire with the
small Heath transmitters. The DX-20 through DX-40.
Bob Macklin
K5MYJ/7
Seattle, Wa.
"REAL RADIOS GLOW IN THE DARK"
Re: [AMRadio] Stealth Antennas?
Ed,
Thanks for the link. Of all the books I have this option is not covered. And
there is no reason it won't work. It just makes the tranmiter more happy. It
won't improve receiver sensativity. It takes real area for that problem.
I understand base loading for the lower HF bands but center loading is
common for 10M and higher. That's why I was considering it.
Also you can bend a wire antenna but should have at least 1/8W from the
feedpoint before the bend.
Bob Macklin
K5MYJ/7
Seattle, Wa.
"REAL RADIOS GLOW IN THE DARK"
- Original Message -
From: "Edward B Richards" <[EMAIL PROTECTED]>
To:
Cc: <[EMAIL PROTECTED]>
Sent: Monday, January 24, 2005 1:20 PM
Subject: Re: [AMRadio] Stealth Antennas?
> Hi Bob;
>
> Base loading a mobile whip allows for taping the coil for a better
> impedance match.
>
> You certainly can use a loading coil in the center of a long wire or wire
> HF antenna. It is quite common to do so. There used to be someone who
> advertised center loading coils for HF antennas. I have not seen an ad
> recently. Spi-Ro MFG, inc www.spiromfg.comoffers shortened antennas
> for some of the amateur bands. Also just the "shorteners". It is easy to
> make your own. Get a couple of one foot pieces of 1-1/4 PVC pipe and some
> varnish insulated # 14 wire and wind your own. Good luck.
>
> 73, Ed Richards K6UUZ
>
>
> On Mon, 24 Jan 2005 12:38:02 -0800 "Bob Macklin" <[EMAIL PROTECTED]>
> writes:
> > I live in a senior apartment where I CANNOT have an outdoor antenna.
> > So I
> > have a wire around the wall at the base of the ceiling. It is
> > currently 1/4W
> > 40M antenna.
> >
> > I did buy the ARRL book on "Stealh Radio".
> >
> > HF mobile antennas use loading coils to make the antenna look
> > longer. The
> > better one us a coil in the center of the antenna.
> >
> > Some apartment antennas are nothing but a mobile whip with a base
> > loading
> > coil. Why BASE LOADING?
> >
> > But the real question is why not use a loading coil at the center of
> > a long
> > wire or dipole to make it look longer? The original Heath Antenna
> > Tuner was
> > just a loading coil("L" section) that allowed use of a SHORT wire
> > with the
> > small Heath transmitters. The DX-20 through DX-40.
> >
> > Bob Macklin
> > K5MYJ/7
> > Seattle, Wa.
> >
> > "REAL RADIOS GLOW IN THE DARK"
> > __
> > AMRadio mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/amradio
> > Help: http://mailman.qth.net/mmfaq.html
> > Post: mailto:AMRadio@mailman.qth.net
> >
>
> __
> AMRadio mailing list
> Home: http://mailman.qth.net/mailman/listinfo/amradio
> Help: http://mailman.qth.net/mmfaq.html
> Post: mailto:AMRadio@mailman.qth.net
>
Re: [AMRadio] Stealth Antennas?
It's in my 2002 handbook also. ONE little short paragraph! LOL!
Right after the expanations of trap antennas. If my noise situation gets to
the point I think I might be able to work 80M I will look at putting a
loading coil in my 40M antenna.
Thanks,
Bob Macklin
K5MYJ/7
Seattle, Wa.
"REAL RADIOS GLOW IN THE DARK"
- Original Message -
From: "Edward B Richards" <[EMAIL PROTECTED]>
To:
Sent: Monday, January 24, 2005 2:28 PM
Subject: Re: [AMRadio] Stealth Antennas?
> Hi again, Bob;
>
> My 2003 ARRL Handbook mentions them on page 20.7. It states that the ARRL
> Antenna Book shows how to design them. Good luck.
>
> 73, Ed Richards K6UUZ
>
>
> On Mon, 24 Jan 2005 13:51:36 -0800 "Bob Macklin" <[EMAIL PROTECTED]>
> writes:
> > Ed,
> >
> > Thanks for the link. Of all the books I have this option is not
> > covered. And
> > there is no reason it won't work. It just makes the tranmiter more
> > happy. It
> > won't improve receiver sensativity. It takes real area for that
> > problem.
> >
> > I understand base loading for the lower HF bands but center loading
> > is
> > common for 10M and higher. That's why I was considering it.
> >
> > Also you can bend a wire antenna but should have at least 1/8W from
> > the
> > feedpoint before the bend.
> >
> > Bob Macklin
> > K5MYJ/7
> > Seattle, Wa.
> >
> > "REAL RADIOS GLOW IN THE DARK"
> >
> > - Original Message -
> > From: "Edward B Richards" <[EMAIL PROTECTED]>
> > To:
> > Cc: <[EMAIL PROTECTED]>
> > Sent: Monday, January 24, 2005 1:20 PM
> > Subject: Re: [AMRadio] Stealth Antennas?
> >
> >
> > > Hi Bob;
> > >
> > > Base loading a mobile whip allows for taping the coil for a better
> > > impedance match.
> > >
> > > You certainly can use a loading coil in the center of a long wire
> > or wire
> > > HF antenna. It is quite common to do so. There used to be someone
> > who
> > > advertised center loading coils for HF antennas. I have not seen
> > an ad
> > > recently. Spi-Ro MFG, inc www.spiromfg.comoffers shortened
> > antennas
> > > for some of the amateur bands. Also just the "shorteners". It is
> > easy to
> > > make your own. Get a couple of one foot pieces of 1-1/4 PVC pipe
> > and some
> > > varnish insulated # 14 wire and wind your own. Good luck.
> > >
> > > 73, Ed Richards K6UUZ
> > >
> > >
> > > On Mon, 24 Jan 2005 12:38:02 -0800 "Bob Macklin"
> > <[EMAIL PROTECTED]>
> > > writes:
> > > > I live in a senior apartment where I CANNOT have an outdoor
> > antenna.
> > > > So I
> > > > have a wire around the wall at the base of the ceiling. It is
> > > > currently 1/4W
> > > > 40M antenna.
> > > >
> > > > I did buy the ARRL book on "Stealh Radio".
> > > >
> > > > HF mobile antennas use loading coils to make the antenna look
> > > > longer. The
> > > > better one us a coil in the center of the antenna.
> > > >
> > > > Some apartment antennas are nothing but a mobile whip with a
> > base
> > > > loading
> > > > coil. Why BASE LOADING?
> > > >
> > > > But the real question is why not use a loading coil at the
> > center of
> > > > a long
> > > > wire or dipole to make it look longer? The original Heath
> > Antenna
> > > > Tuner was
> > > > just a loading coil("L" section) that allowed use of a SHORT
> > wire
> > > > with the
> > > > small Heath transmitters. The DX-20 through DX-40.
> > > >
> > > > Bob Macklin
> > > > K5MYJ/7
> > > > Seattle, Wa.
> > > >
> > > > "REAL RADIOS GLOW IN THE DARK"
> > > > __
> > > > AMRadio mailing list
> > > > Home: http://mailman.qth.net/mailman/listinfo/amradio
> > > > Help: http://mailman.qth.net/mmfaq.html
> > > > Post: mailto:AMRadio@mailman.qth.net
> > > >
> > >
> > > __
> > > AMRadio mailing list
> > > Home: http://mailman.qth.net/mailman/listinfo/amradio
> > > Help: http://mailman.qth.net/mmfaq.html
> > > Post: mailto:AMRadio@mailman.qth.net
> > >
> > __
> > AMRadio mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/amradio
> > Help: http://mailman.qth.net/mmfaq.html
> > Post: mailto:AMRadio@mailman.qth.net
> >
>
> __
> AMRadio mailing list
> Home: http://mailman.qth.net/mailman/listinfo/amradio
> Help: http://mailman.qth.net/mmfaq.html
> Post: mailto:AMRadio@mailman.qth.net
>
Re: [AMRadio] Stealth Antennas?
Jim, I have all the concerns you are mentioning. I don'y hear much on 80M except some digital stuff much like tty but it's not tty. And I have a major noise problem right in the entire AM window. I am a Heath collector. but I don't collect unbuilt kits. Right now I am trying to get a DX-60/HR-10 up on 40M CW. So far I have not heard anyone on 40M AM. I also have a SB-301/SB-401 to get on the air. Both recievers are operational. But I have not fired up the transmitters yet. I hope to do so about the first of the month. I do have a portable station. A Heath Cheyenne/Commanche Tx/Rx pair with the mobile power supply. I am planning to try them up on Mt. Rainier. But they again are CW/AM riggs. 40M and up are pretty good. I can copy a lot of CW on 40 in the evenings if there is any activity. When there is a contest there is planty to copy. I also have both 6M and 2M AM/CW trancievers. The 2M FM overloads my TV so I suspect it is also getting some of my neighbors. But My 2M HT is OK. I can talk to myself on it but I can't hit the repeater. When I got back into ham radio a couple of years ago I did not live in this apartment. I lived in my daughters house but she had to move to Denver and I elected to stay here. And I have only worked on the radios on a time availble basis. it's now winter and the time is available. I fly model airplanes in the summer. Thanks, Bob - Original Message - From: "Jim candela" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Monday, January 24, 2005 8:30 PM Subject: RE: [AMRadio] Stealth Antennas? > > Bob, > > A couple of thoughts on this indoor antenna idea. It is true that you > might hit upon a combination that radiates "fairly" well on some bands. With > a 100 watt rig (20-25 watts AM), your good for some contacts so long as your > receiver can hear amateur signals. More than likely you will be hearing > every FCC Part 15 device, and DSL, BPL, cable Modems, computers, light > dimmers, TV sets, touch switch lamps, etc. that are in the complex that will > be spraying spurious crap all over the spectrum. Even if you do hear > amateurs, your going to "interfere" with these same devices like crazy, and > even though it won't be technically your fault, a whole heard of folk will > be after you like a pack of dogs. > > One way to insure that you will be hated is to use a higher power rig like > a Globe King 500B, or a rice box into a SB-220 and run AM! CW is best at > lower power; SSB is hard to understand, but AM, well forget it. They will > quickly say, that is Bob Simenstad in apt 307. Get ready for some heavy duty > door knocking. When you get on, EVERY PC speaker, and many Dolby digital 5.1 > surround systems will power up from your RF, and emit your voice into your > neighbor's apartments. Many a ham has had his spouse side with the neighbors > too. So that's something else you won't be getting. The PC speaker problem > means you cannot wait until midnight anymore to operate. It will act as an > alarm clock and wake everybody up. > > Bob, I don't mean to burst your bubble about a HF apartment ham station. I > would however lower your expectations, and keep your operating to just a few > hours per week, and the power below 100 watts. > > Alternatively, more than one ham with an effective HF mobile set-up parks > the car near their apartment, and late at night they run outside with some > coax, and connect it to the mobile antenna on their vehicle. You could also > make this wireless, and use the car as a remote transmitter. If you do the > remote approach, then you could conceivably park the car away and on top of > a nearby hill. > > Regards, and Good Luck, > Jim Candela > WD5JKO > > > -Original Message- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Bob Macklin > Sent: Monday, January 24, 2005 4:43 PM > To: Discussion of AM Radio > Subject: Re: [AMRadio] Stealth Antennas? > > > It's in my 2002 handbook also. ONE little short paragraph! LOL! > > Right after the expanations of trap antennas. If my noise situation gets to > the point I think I might be able to work 80M I will look at putting a > loading coil in my 40M antenna. > > Thanks, > > Bob Macklin > K5MYJ/7 > Seattle, Wa. > > "REAL RADIOS GLOW IN THE DARK" > > - Original Message - > From: "Edward B Richards" <[EMAIL PROTECTED]> > To: > Sent: Monday, January 24, 2005 2:28 PM > Subject: Re: [AMRadio] Stealth Antennas? > > > > Hi again, Bob; > > > > My 2003 ARRL Handbook mentions them on page 20.7. It states that the ARRL > > Antenna Book shows how to design them. Good luck. > > > > 73, E
Re: [AMRadio] Stealth Antennas?
IIn a house we bought 3 years ago my daughter had an alarm system installed. The wireless sensors on the doors and windows transmitted BLIPS on 2M. Bob Macklin K5MYJ/7 Seattle, Wa. "REAL RADIOS GLOW IN THE DARK" - Original Message - From: "Jim Candela" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Tuesday, January 25, 2005 10:32 AM Subject: Re: [AMRadio] Stealth Antennas? > > John, > > the last i checked door bell transformers are > still 60 hertz step down transformers that transform > 120 vac or 240 vac to 24 volts ac. This should not > cause interference. I wonder what was happening in > your example. Any ideas? > > Regards, > Jim > > > --- [EMAIL PROTECTED] wrote: > > > Don't overlook those screw in fluorescent light bulb > > replacements. They > > really generate some nasty RF as do the X-10 remote > > light switches and outlets and > > the infamous doorbell transformers. While we are on > > that subject, I recently > > heard of a problem with the 24V control transformer > > on a furnace that was > > causing a lot of grief and was so bad that it was > > even getting into the resident't > > tv picture with what looked like line noise. > > > > 73, > > > > John, W4AWM > > > __ > > AMRadio mailing list > > Home: > > http://mailman.qth.net/mailman/listinfo/amradio > > Help: http://mailman.qth.net/mmfaq.html > > Post: mailto:AMRadio@mailman.qth.net > > > > __ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:AMRadio@mailman.qth.net >
[AMRadio] 20V-3 Front Door Latches
I am in need of a front lower door latch. There is one on each side, I have the left side latch only. I need both parts, the part that mounts to the door and the part that mounts inside the pillar. Also, I am looking for a replacement R-122 7.5K @ 100W. The one in my unit measures open. Evidently the radio station that had this transmitter blew up the original because they replaced it with a 10K ohm resistor and that's the one that is open. Anyone have this in their junk box and willing to part with it? Otherwise, it's off to Mouser. Thanks, Bob W6TR
Re: [AMRadio] 20V-3 Front Door Latches
How much, where is it, what condition, pics? Bob - Original Message - From: "David Knepper" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" Sent: Tuesday, January 25, 2005 3:52 PM Subject: Re: [AMRadio] 20V-3 Front Door Latches With these resistors reasonably priced, I would suggest you buy a new one. The latches were made in England and are no longer available unless someone has a "junker" 20V-3. I own serial number 239 and it for sale. Dave, W3ST Publisher of the Collins Journal Secretary to the Collins Radio Association www.collinsra.com Nets: 3805 Khz, Monday/Wednesdays 8 PM EDST 14250 Khz Saturday, 12 Noon EDST ----- Original Message - From: "Bob Maser" <[EMAIL PROTECTED]> To: "AMRadio" Sent: Tuesday, January 25, 2005 5:14 PM Subject: [AMRadio] 20V-3 Front Door Latches I am in need of a front lower door latch. There is one on each side, I have the left side latch only. I need both parts, the part that mounts to the door and the part that mounts inside the pillar. Also, I am looking for a replacement R-122 7.5K @ 100W. The one in my unit measures open. Evidently the radio station that had this transmitter blew up the original because they replaced it with a 10K ohm resistor and that's the one that is open. Anyone have this in their junk box and willing to part with it? Otherwise, it's off to Mouser. Thanks, Bob W6TR __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
