RE: [AMRadio] 10 meter AM
The HTX-10 is a winner on AM. Audio sounds very nice even with the stock mic. I love mine. Current draw is low and works great with an amplifier, going from the 7 watt carrier to 70 watts with most good amplifiers. I worked Japan with that rig in the truck a few years ago! When 10 is open, 7 watts is at least 5-5 anywhere in the country. George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Mark Cobbeldick Sent: Thursday, November 04, 2004 8:58 AM To: amradio@mailman.qth.net Subject: Re: [AMRadio] 10 meter AM Thank you to everyone who replied. I have a good place to start. Going to order crystals for 29.0 and 29.1 next week, then start the retuning after they are received. An old ham friend of mine in Georgia just gave me a RS HTX-10 mobile, which also has AM. I will try playing with that until the CB to 10m conversion is done.But tube rigs still sound better to me! BTW: Been seeing a lot of good DX on the FM end of the 10m band lately. I run converted commercial gear on 29 MHz FM, and run the 10m fm list on Yahoo http://groups.yahoo.com/group/AR29MHz-FM/ but have been wanting to play on 10m AM too. This will be a good start. I work professionally in the two-way radio business as a Master Technician at the factory in Lynchburg, VA, and know all too well how easy it is to get burned-out and not want to tinker with amateur radio as a hobby. (I was that way for years...) But I grew-up listing to stories recounted by my Elmer (Santiago, WA4KSD) of the 50's heyday of 10m 6m AM Phone. By mostly staying off the 2 440 repeater bands and doing something a tad different, the hobby is still fun. 73, Mark Cobbeldick, KB4CVN Monroe, VA __ Do you Yahoo!? Check out the new Yahoo! Front Page. www.yahoo.com __ 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] 813 tx
I had one of those rigs as a kid BEFORE I WAS A HAM. I used it on CB modulated with 811A's. Then I found out about Amateur Radio. A backwards experience. Years later I parted it out, unknowing it was so well documented. I actually traced that thing out and drew the schematic at 16 years old. The rig sat at the high school in a corner for years... The instructor gave it to me to male room at the end of June. I spent my summer vacation that year on the CB band with that thing. Some of that rig is here and there in the shack, sort of a ghost. When I saw it in the 1956 handbook I bought at a fest... I almost had tears. It WAS the one I had. George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of CHRIS PAPAIOANNOU Sent: Tuesday, October 26, 2004 5:02 AM To: Discussion of AM Radio Cc: peter A Markavage Subject: Re: [AMRadio] 813 tx tnx Pete.. Chris,SV1DAF. - Original Message - From: peter A Markavage [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Tuesday, October 26, 2004 9:02 AM Subject: Re: [AMRadio] 813 tx Here's some: http://www.amwindow.org/tech/htm/813/813.htm http://www.remote.arrl.org/tis/info/pdf/5401011.pdf http://www.remote.arrl.org/tis/info/pdf/5610033.pdf http://www.remote.arrl.org/tis/info/pdf/57hb192.pdf Doing a Google search on 813 transmitter turned up 49 hits. Pete, wa2cwa On Tue, 26 Oct 2004 06:44:32 +0300 CHRIS PAPAIOANNOU [EMAIL PROTECTED] writes: 73 to all group's members around, i'm new in this list.My name is Chris,my call is SV1DAF and i'm located in Athens,Greece. I'm not new in AM..20-25 years ago there was too much AM activity here,with homemade tube rigs,in the MW band.Was illegal but there was.Then most of the amateursbecame hams with legal activity in the ham bands.The rest of them left the radiowaves. Not long ago i started homebrewing again after long time.My homebrew rigs now are: 1)6V6/807 crystal controlled where the 1st tube is the oscillator tube and the 2nd one the pa one. 2)6J5/EL34 I prefer plate modulation and the reasons are known and clear,and i'm using an amp with 2 EL504s like output tubes.These are sweep tubes. I'm now searching for a tx drawing with an 813 tube like pa tube.Any replies will be too much appreciated. Tnx for the attention paid to my introduction, 73,Chris,SV1DAF. Speed up your surfing with Juno SpeedBand. Now includes pop-up blocker! Only $14.95/ month - visit http://www.juno.com/surf to sign up today! __ 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] New Bandwidth Rules
How about 16 KHz bandwidth at 29.0 MHz!!! There is no practical differentiation in bandwidth between AM and FM on TEN in that portion of the band??? I'm sure no-one would object to a 16 KHz wide AM high-Fi signal on 29 MHz AM! George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of peter A Markavage Sent: Tuesday, October 26, 2004 12:05 PM To: [EMAIL PROTECTED]; amradio@mailman.qth.net Subject: Re: [AMRadio] New Bandwidth Rules Brian: Have you actually read the entire proposal, especially the sections that mention AM? Is 9 KHz AM bandwidth not enough for you? Go here to read the entire proposal: http://www.arrl.org/announce/bandwidth.html Pete, wa2cwa On Tue, 26 Oct 2004 06:11:44 -0400 Brian Carling [EMAIL PROTECTED] writes: SO does this ARRL ACtion mean they are going to further infringe on AM by limiting bandwidth and dividing upi the bands on that basis rather than the present rules? It is SICKENING to think that they might further restrict AM operation! SB QST ARL ARLB031 ARLB031 Draft Bandwidth Petition, BPL Focus of ARRL Executive Committee Meeting Meeting October 16 in Dallas, Texas, the ARRL Executive Committee (EC) devoted much of its fall session to a discussion of comments received on ARRL's draft FCC petition seeking regulation of subbands by bandwidth rather than by emission mode. The EC also authorized the filing of a Petition for Reconsideration in response to the BPL Report and Order (RO) in ET Docket 04-37, which the FCC adopted October 14. Drafting and filing the petition must await release of the actual RO, which should happen in a few weeks. Responding to a synopsis of the bandwidth petition and proposed rule changes posted on the ARRL Web site, several hundred League members and others in the ham radio community offered comments and suggestions. ''The Executive Committee found considerable support for the concept of the petition,'' said ARRL CEO David Sumner, K1ZZ, ''along with constructive suggestions to reduce both the impact of the changes on current amateur operations, as well as possible unintended consequences. Earlier this year, the EC decided to make a synopsis and explanation of the petition available to ARRL members before filing it with the FCC. At this month's meeting, the EC agreed to submit several recommended amendments to the proposed rules changes to the ARRL Board of Directors for its consideration in January. These include: * Retention of rules permitting automatically controlled digital stations (packet and other digital modes) in narrow HF subbands. The draft petition had proposed dropping these provisions. * A rule prohibiting so-called semi-automatic digital operation (automatic control in response to a communication initiated by a live operator) on frequencies below 28 MHz where phone is permitted. This addressed a concern that ''robot'' digital stations might take over the phone bands. In other words, these bastards can continue to JAM CW and digital QSOs below the phone bands like they are now on 40m and 20m all day, every day! BUT we will make it so the phone boys don't rush to the aid of the CW and digital OPS who are screaming about he QRM from these damn UNATTENDED ROBOTS! THANKS DIGITAL COMMITTEE! * A segment for 3 kHz bandwidth (no phone) emissions at 10.135-10.150 MHz to accommodate existing and planned digital operations. SO! We are going to NOW allow PACTOR-WINLINK's UNATTENDED ROBOTS to aslo come and jam the digital ops on 30m too. GREAT ARRL! You take the cake! * Deletion of the word ''continuous'' from the description of test transmissions authorized on most frequencies above 51 MHz. * Simplification of proposed changes to 97.309 to clarify that FCC-licensed amateur stations may use any published digital code as long as other rules are observed. Sumner emphasized that the recommendations address major issues raised to date but were not necessarily the last word on the draft petition. The ARRL's bandwidth proposals take into account the League's prior ''Novice refarming'' petition to expand some HF phone bands--included in the ''omnibus'' FCC Notice of Proposed Rule Making in WT Docket 04-140. The EC also authorized ARRL General Counsel Chris Imlay, W3KD, to ''prepare to pursue other available remedies as to procedural and substantive defects'' in the BPL proceeding. Speed up your surfing with Juno SpeedBand. Now includes pop-up blocker! Only $14.95/ month - visit http://www.juno.com/surf to sign up today! __ 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] Home Brew
Joe, If you are going to cathode modulate that 4X1... Consider PDM Digital. You will need twice the plate voltage +20% if you want 120% positive peak audio capability. The 4-125 is the only tube in your list that can possibly hold off the voltage and it's close at that. FYI: I am finishing up a Class-D 4-1000 PDM modulator for my 4-1000 Class C stage. It's a series modulator that will feed the 4-1000 class C plate and is unique, with a floating cathode pulsed at 110KHz at 7KV. I call it high-side-PDM. This way a conventional RF deck can be PLATE MODULATED. The grid switcher uses FETS, and the screen supply also floats at the 7KV level. Optical coupling is used to get the PDM stream to the grid fets. If you are interested in such a crazy project, let me know. It will be nice to have digital audio from the class C 4X1 on 80-10 Meters... If it works and I survive the testing process (scared). The rig will be called 4X1X4X1 George AB2KC. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Crawfish Sent: Tuesday, September 28, 2004 11:19 PM To: Discussion of AM Radio Subject: Re: [AMRadio] Home Brew I am trying to figure out how to cathode modulate the 4-1000 I have. I have a pair of 813's and have a 4-125. Have a bunch of 807's and 1625's as well. Joe W4AAB - Original Message - From: [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Tuesday, September 28, 2004 6:47 PM Subject: Re: [AMRadio] Home Brew There are all kinds of good designs in the 50's handbooks. The most fun you will have is trying to find all the parts. 73, John, W4AWM I'd like to build my own AM transmitter. Tube style; more than 200 watts. __ 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] WTB SB-220
An S1 signal above the noise level IS the difference to being heard or not. The same is true if the band is on the way out... And the backscatter signal is kicked up 6 dB or better... At least you can finish-out the QSO with QRO. It's nice to have the juice when you need it. QRO is also fun on Ten meters with marginal band openings. George AB2KC 4X1 plate modulation lives on TEN meters -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of RJ Mattson Sent: Monday, September 27, 2004 7:07 PM To: Discussion of AM Radio Subject: Re: [AMRadio] WTB SB-220 Again, It would be an S1 signal above a s9/30db level noise - a barely perceivable difference. You would have to go from 100 to ~ 6,400 watts to get an S3 signal above that noise level. bob...w2ami www.qrz.com/callsign/w2ami - Original Message - From: George Pritchard [EMAIL PROTECTED] To: 'Discussion of AM Radio' amradio@mailman.qth.net Sent: Monday, September 27, 2004 9:38 AM Subject: RE: [AMRadio] WTB SB-220 When the interference is also at 30 over S9(even if it's static crashes) a 36 dB over signal using the 400 watts helps. First put up the best ant... Then crank-it with juice!!! George AB2KC 1KW 4X1 lives -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of RJ Mattson Sent: Monday, September 27, 2004 9:27 AM To: Discussion of AM Radio Subject: Re: [AMRadio] WTB SB-220 No matter what the spin, 100 to 400 watts is only 1 s-unit and barely perceptible at the receiver. A 30db/s9 signal is from a good antenna not from 100 or 400 watts. bob...w2ami www.qrz.com/callsign/w2ami - Original Message - From: Jim Candela [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Sunday, September 26, 2004 10:47 PM Subject: Re: [AMRadio] WTB SB-220 Hmmm, the boys on 3878 are running 1500 watts pep plus on USB, and there is a 100 watt AM'er calling CQ on 3880. How much of an antenna would the AM'er need to overcome the S/N ratio? I think Astabula Bill, W8VYZ says it all: http://www.amwindow.org/audio/mov/w8vyz.mov Ever hear Bill running 100 watts? When Bill and Less K6HQI (sk) were regulars on 14286 they had to run heavy iron to hold the frequency. A 100 watt rig was seldom heard whereas a 500 watt rig (that 6db again) was often armchair copy, and sometimes often drive the QRM away. Regards, Jim RJ Mattson [EMAIL PROTECTED] wrote: If you can't get out consistantly with a Viking II, you need an antenna - not an amp. bob...w2ami www.qrz.com/callsign/w2ami __ 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] WTB SB-220
Go from 1 million watts to 2 million watts and it's the same 3 dB. That's expensive! That's where antenna gain is really cheap (assuming it doesn't melt the ant). Dbs really get expensive once you get past 1KW. George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Edward B Richards Sent: Tuesday, September 28, 2004 1:08 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] WTB SB-220 Hi Bret; That could be because the ratio of 25 watts to 100 watts is 4, an increase of 6 dB, while the ratio of 300 to 500 is 1.7, an increase of 2.2 dB and 300 to 600 is a ratio of 2 or 3 dB. 73, Ed Richards K6UUZ On Tue, 28 Sep 2004 08:14:24 -0400 Brett gazdzinski [EMAIL PROTECTED] writes: I know about the DB thing, but people running a bit of power always seem much stronger than the guys running 25 or 50 watts. I cant say why, but in a qso with a bunch of people, the guys running 200 to 300 watts are always much stronger on the meter, and sounding, than the 50 watt guys. For some reason, the biggest jump seems to be between about 25 watts and 100 watts. I don't think you HEAR as much change between say 300 and 500 watts, or even 300 and 600 watts, but go between 25 and 100 watts and it seems very noticeable at the other end. Maybe the losses in the antenna circuit are a much bigger percentage of the power out when running 25 or 50 watts? You can see the difference in signal strength when someone turns up the power, and it seems to track with the DB rule, but there still seems to be some threshold effect in most cases. With 25 watts, its hard to get clearly above the noise floor in many cases, while 100 watts and up does it easy in clear band conditions. Most times, on clear conditions on 40 meters, the guy running the rice box at 25 watts is just above the noise floor at about 1 s unit. He may run between s1 and s3. The guy running 100 watts will run s6 to s9 or higher, and be arm chair copy. That FIRST 3 to 6 db boost seems to be the most critical. And I have NEVER heard someone running 25 watts and a REALLY good antenna out strapping a 500 watt rig into a regular antenna. And, although its easy to run an amp and boost power a little, it seems crazy to run a pair of heavy tubes and get 300 watts out, when a pair of 813 tubes plate modulated will do 700 watts of carrier easy, and well over 2000 watts pep! A pair of 812a's will give 300 watts carrier without trouble! Brett N2DTS -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of RJ Mattson Sent: Monday, September 27, 2004 7:07 PM To: Discussion of AM Radio Subject: Re: [AMRadio] WTB SB-220 Again, It would be an S1 signal above a s9/30db level noise - a barely perceivable difference. You would have to go from 100 to ~ 6,400 watts to get an S3 signal above that noise level. bob...w2ami www.qrz.com/callsign/w2ami - Original Message - From: George Pritchard [EMAIL PROTECTED] To: 'Discussion of AM Radio' amradio@mailman.qth.net Sent: Monday, September 27, 2004 9:38 AM Subject: RE: [AMRadio] WTB SB-220 When the interference is also at 30 over S9(even if it's static crashes) a 36 dB over signal using the 400 watts helps. First put up the best ant... Then crank-it with juice!!! George AB2KC 1KW 4X1 lives -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of RJ Mattson Sent: Monday, September 27, 2004 9:27 AM To: Discussion of AM Radio Subject: Re: [AMRadio] WTB SB-220 No matter what the spin, 100 to 400 watts is only 1 s-unit and barely perceptible at the receiver. A 30db/s9 signal is from a good antenna not from 100 or 400 watts. bob...w2ami www.qrz.com/callsign/w2ami - Original Message - From: Jim Candela [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Sunday, September 26, 2004 10:47 PM Subject: Re: [AMRadio] WTB SB-220 Hmmm, the boys on 3878 are running 1500 watts pep plus on USB, and there is a 100 watt AM'er calling CQ on 3880. How much of an antenna would the AM'er need to overcome the S/N ratio? I think Astabula Bill, W8VYZ says it all: http://www.amwindow.org/audio/mov/w8vyz.mov Ever hear Bill running 100 watts? When Bill and Less K6HQI (sk) were regulars on 14286 they had to run heavy iron to hold the frequency. A 100 watt rig was seldom heard whereas a 500 watt rig (that 6db again) was often armchair copy, and sometimes often drive the QRM away. Regards, Jim RJ Mattson [EMAIL PROTECTED] wrote: If you can't get out consistantly with a Viking II, you need an antenna - not an amp. bob...w2ami www.qrz.com/callsign/w2ami __ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http
RE: [AMRadio] WTB SB-220
When the interference is also at 30 over S9(even if it's static crashes) a 36 dB over signal using the 400 watts helps. First put up the best ant... Then crank-it with juice!!! George AB2KC 1KW 4X1 lives -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of RJ Mattson Sent: Monday, September 27, 2004 9:27 AM To: Discussion of AM Radio Subject: Re: [AMRadio] WTB SB-220 No matter what the spin, 100 to 400 watts is only 1 s-unit and barely perceptible at the receiver. A 30db/s9 signal is from a good antenna not from 100 or 400 watts. bob...w2ami www.qrz.com/callsign/w2ami - Original Message - From: Jim Candela [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Sunday, September 26, 2004 10:47 PM Subject: Re: [AMRadio] WTB SB-220 Hmmm, the boys on 3878 are running 1500 watts pep plus on USB, and there is a 100 watt AM'er calling CQ on 3880. How much of an antenna would the AM'er need to overcome the S/N ratio? I think Astabula Bill, W8VYZ says it all: http://www.amwindow.org/audio/mov/w8vyz.mov Ever hear Bill running 100 watts? When Bill and Less K6HQI (sk) were regulars on 14286 they had to run heavy iron to hold the frequency. A 100 watt rig was seldom heard whereas a 500 watt rig (that 6db again) was often armchair copy, and sometimes often drive the QRM away. Regards, Jim RJ Mattson [EMAIL PROTECTED] wrote: If you can't get out consistantly with a Viking II, you need an antenna - not an amp. bob...w2ami www.qrz.com/callsign/w2ami __ 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] Pix of BPL hardware on utility poles in Cincinnati
Gentlemen, How long will it be before the govt' adds interface devices to the BPL home internet connection to further invade in on our privacy. I feel very uncomfortable with potential broadband utility monitoring of my electric meter! It opens the door to much invasion. Live Free or die. The 20 gauge and bird shot is interesting. George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Donald Chester Sent: Thursday, July 22, 2004 2:17 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] Pix of BPL hardware on utility poles in Cincinnati Actually this provides additional advantages to the Utility Companies even if you don't subscribe to the internet service. A modem could be hung on your electric, gas, or water meters, plugged into an AC outlet, and now all meter readings could be done back at their facilities via the BPL internet connection, eliminating the services of electric, gas, or water meter readers. Wonder how long before some would develop and put on the market bootleg brown boxes -remember the blue boxes in the 80's that allowed one to illegally bypass the phone co.'s billing and make free phone calls? These things would take over and alter the data stream to the utility company and illegally reduce your bill. Or if you happened to transmit over the air at the critical moment and your signal caused data loss and scrambled the data so that you or a near by resident erroneously got a ridiculously high utility bill for services you did not use. Incidentally, Apple Computers got its start as a garage enterprise that produced blue boxes, and once they gained some capital, decided to go legit and put together the first personal computer, that started a technological revolution, even though the machine was extremely crude by today's standards. _ Don't just search. Find. Check out the new MSN Search! http://search.msn.click-url.com/go/onm00200636ave/direct/01/ __ 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] DX-100
Replace the circuit with this modification. Works well with my DX-100. The carbon element pot is smooth and will never fail since it sees low current. Also... Spread out the turns on the 10/15 meter 6146 grid coil pair to get lots more grid current at 10/15 meters. If the coil turns are not spread out a bit, the Q is very low. http://www.amwindow.org/tech/htm/drivepot.htm Good luck, George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Edward B Richards Sent: Sunday, July 18, 2004 7:58 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] DX-100 Another thought: Maybe the driver is not seeing the oscillator and breaks into oscillation at max gain. Check that the oscillator is working. Pull the oscillator tube and see if it does the same thing. Be sure the VFO is outputting several volts at the correct frequency, that the crystal/VFO switch is in the VFO position (don't ask me how I know), That the crystal/VFO switch is working. Check that you have adequate drive to the driver grid. Good luck. 73, Ed Richards K6UUZ On Sun, 18 Jul 2004 16:19:43 -0700 Edward B Richards [EMAIL PROTECTED] writes: Hi Gary, et al: This is the way an oscillator acts. Check to be sure the VFO is not going in and out of oscillation. It is also possible that the driver or PA is going in and out of oscillation. Good luck. 73, Ed Richards K6UUZ On Sun, 18 Jul 2004 18:22:20 -0400 Gary Poland [EMAIL PROTECTED] writes: I have tried a new 12BY7A and 5763 with no change. With the DX100 in CW and the PLATE switch off...I have to run the DRIVE pot fully CW before the GRID current shows on the meter. Once peaked with the DRIVER TUNE and set at 5 ma all is well until I run the DRIVE pot back down CCW. Then running it back up results in no grid current until I max out the pot again. This will also occur if I move the DRIVER capacitor off peak. I always have to max out the DRIVE pot Really screwy HI HI. 73, Gary __ 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] Brian with crystals please e-mail back
Sorry for this shout-out, but my hard drive crashed yesterday. Brian, I lost all e-mails... So please send your address and all e-mails we did about the crystals. I wanted to send the money order today, but the info was lost. I'll send the MO out when I receive your e-mail. Thanks, George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Neal Newman Sent: Thursday, April 15, 2004 7:45 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] RCA BTA-250 I believe there is a transmitter 250 watt in Mississippi but he has to go and get it... Look for Paul walker Jr of WQMA [EMAIL PROTECTED] I believe WQMA is looking for someone to remove their old RCA transmitter Geoff/W5OMR wrote: I received a phone call from a TV Station engineer in MS yesterday, who's looking for an RCA 250w broadcast rig to move to 160m to operate AM with. As I was mobile, driving back to San Antonio from Houston, I don't recall the specifics, other than he is a ham, is an engineer at WTOK, and was looking for a low-power broadcast AM transmitter. his phone number is (601) 693-1441 Perhaps someone here could help. 73 = Best Regards, -Geoff/W5OMR ___ 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] Re: AMRadio digest, Vol 4 #298 - 8 msgs
Patrick, I got in very late last few days, I'll try to look at the 304TL filaments tonight. I'll take digital pictures of them lit up for you. George KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of patrick jankowiak Sent: Wednesday, January 21, 2004 9:32 PM To: amradio@mailman.qth.net Subject: [AMRadio] Re: AMRadio digest, Vol 4 #298 - 8 msgs I have only the tube. I had been building an amplifier, and had a socket and 4 tubes, but traded the stuff off, except I could not find the 4th tube. I let the guy hold a couple of my 100uF 4KV non-pcb oil caps for it, but it didn't turn up, I could not find it, for a year. By that time he had sold the caps to someone, so I kept the tube. so that's the story, it's in the correct type box etc, just I have no use for it. I'll trade. The 4cx5000A has a bit of external tarnish from sitting, but I don't think it is harmed. Patrick Message: 1 From: George Pritchard [EMAIL PROTECTED] To: amradio@mailman.qth.net Subject: RE: [AMRadio] trade 4CX5000A for .. Date: Tue, 20 Jan 2004 09:37:44 -0500 Reply-To: amradio@mailman.qth.net Patrick, I may have the pair of 304THs. I'll check tonight, and verify the filaments with a valid light-up since I have a fixture set up with the correct socket and the correct filament transformer. The 4CX5K may be fun to play with. Do you have the socket or chimney for it?? George AB2KC ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
RE: [AMRadio] trade 4CX5000A for ..
Patrick, I may have the pair of 304THs. I'll check tonight, and verify the filaments with a valid light-up since I have a fixture set up with the correct socket and the correct filament transformer. The 4CX5K may be fun to play with. Do you have the socket or chimney for it?? George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of patrick jankowiak Sent: Monday, January 19, 2004 9:31 PM To: amradio@mailman.qth.net Subject: [AMRadio] trade 4CX5000A for .. I have a good used 4CX5000A to trade. can't test it, but I will guarantee it to work. Need any of the following good tubes, listed in order of urgency: 4-1000A 304TH (prefer pair) 250TH or combine whatever, but those are what I'm needing. Thanks, Patrick ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
RE: [AMRadio] Modulation of the screen grid
For Patrick, I use the same tube compliment: 4X1 with the 304TLs. As far as the 4X1 screen goes... I use a huge choke, just because I had it available. 500VDC. I see the screen current bounce up from 130 ma to 175 ma approx during modulation on the typical Simpson current meter. The signal reports are clean audio. I would keep it simple. The second transformer is probably going to give different phase relationship. The screen inductor should be more in-step with a mod transformer... if big enough. FYI, I use the stancor polypedance 600W mod transformer with the same heising connection you have also, and floated the xformer iron from ground to prevent arc-over to ground. The xformer still talks back a bit. Man those 304TLs put out some audio!!! Great tubes. Very high plate current capability before saturation. George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of patrick jankowiak Sent: Sunday, November 30, 2003 2:39 AM To: amradio@mailman.qth.net Subject: [AMRadio] Modulation of the screen grid Would anyone mind looking over the schematic at the web page below and see if I am on the right track to modulate the G2 voltage of a 4-1000? This should provide the 250 volt peak voltage necessary for the screen grid, and then I won't have to rely on using just a choke from the screen supply or a dropping resistor. Basically I plan to use a smaller mod xfmr to couple some of the modulated plate voltage to the screen. Maybe I have some mistakes in the parts or signal level values, but I think it should be right. Thanks in advance, Patrick http://208.190.133.201/mod001.gif ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
RE: [AMRadio] FS: BC-779-B w/xtal oscillator, rack cabinet, misc
DIDYA SELL THE CABINET? George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Merz Donald S Sent: Wednesday, November 12, 2003 12:42 PM To: amradio@mailman.qth.net; [EMAIL PROTECTED]; [EMAIL PROTECTED]; 'Glowbugs (E-mail); 'Baswaplist' (E-mail) Subject: [AMRadio] FS: BC-779-B w/xtal oscillator, rack cabinet, misc For Sale Gray rack cabinet. This is a standard 19 wide rack cabinet with 12.25 inches of rack space. The internal depth is 14.75 inches. This means that this cabinet will hold and R390, R390A and any of the early Super-Pros. It is not deep enough to hold an SP-600. This has an access door on top and louvers on the sides. It is painted a dark battleship gray and has lots of scuffs and scratches. The mounting rails have threaded holes for mounting screws. $50 Picture available. Now here's something different. This is a post-war BC-779-B Super-Pro to which a crystal oscillator modification kit has been bolted on. The radio itself has no military tag. the Hammarlund tag on the back is unreadable except for the embossed notation LXR and 4550. The xtal oscillator kit add-on has a military tag that says Improvement Kit MC-531. The kit was made under a 1949 contract. This radio comes with a matching military power supply RA-84A made by Howard Radio in 1942 with a 1951 MWO stamp. Both radio and power supply are rack mount. They both have top and bottom covers. This radio was part of a diversity receiver setup called the AN/FRR-12. The crystal oscillator is clearly shown in manual TM 11-896. This setup dates from between 1948 and 1951. The radio front panel is dark gray and the power supply panel is light gray. I think the radio panel has been repainted. The radio has all the original knobs. The band switch, band spread and tuning controls all work as they should. The meter is original and looks good. This set comes with the original manual for AN/FRR-12 (TM 11-896) which clearly shows the crystal oscillator setup. The manual is unfortunately missing the schematic but I can supply a copy of a BC-779-B schematic to fill the void. Also comes with the correct cable to attach the radio to the power supply. All original as far as I can see. Untested and assumed to need restoration. As-is. $75 Pictures available. Heathkit AR-27 solid state FM receiver with original manual. 1969-vintage. Needs cleaned but will look excellent when done. Appears to be all original. Untested. As-is. $8 Sams Auto Radio Manual Volumes 12 and 23. These cover over 110 car radios from 1959 through 1963. Many popular brands. $11 including postage. Thanks for looking. 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] 4-1000A Socket needed
Is $75 ok? I was actually looking for the black plastic non-air type socket since the grids and cathode will be at +7500V for the PDM circuit. After thinking about it... I may be able to mount the aluminum socket on thick plexiglass to insulate it from the chassis. Thanks for offering them to me. Please e-mail back with the total you need and your address. 73s George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Tuesday, June 10, 2003 9:23 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] 4-1000A Socket needed Hi George, I have a new cast aluminum socket and new chimney. I bought these new a a while back with good intentions of build a big amp, but other projects keep coming up. Make me an offer. 73's Butch ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
RE: [AMRadio] big iron AM rig built by silent key Durwood Tucker
Patrick, The 4-1000A and the 304TH rig sounds great, and will be fun to operate. I built a rig with the same tube compliment, however... I use 304TLs to modulate the 4X1. The TL version of the 304s will give you better linearity, but you will need to lower the bias voltage since these have a bit more gain and will need less audio drive level. I run the whole thing very conservative at 2800VDC and get 750 Watt+ carrier 80-10M, and 125% modulation with the Stancore 600W polypedance tranny and a heising connection. You may want to consider the 3-Diode negative peak loading circuit with the keep-alive power supply to protect the mod-tranny from 100% negitive modulation. E-mail back and we can chat if you like, since we basically have the same rig. George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Mike Dorworth K4XM Sent: Friday, June 06, 2003 8:05 AM To: amradio@mailman.qth.net Subject: Re: [AMRadio] big iron AM rig built by silent key Durwood Tucker I'm looking for any information on a transmitter I rescued. It uses a 4-1000A modulated by a pair of 304TH's and the HV meters read to 5000 volts... I don't know how much power it is capable of but I am sure it is 'enough'. Patrick . Placed in perspective of a Collins 30K1, it has 4 times the audio, and 875 watts more plate dissipation in the final tube, yeah! a conservative rated rig! mike, k4xm --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.487 / Virus Database: 286 - Release Date: 06/01/2003 ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
[AMRadio] 4-1000A Black plastic Socket
Anybody have a 4-1000A socket that they would like to sell it to me? I need one for my Pulse Duration Modulator build. Thanks George AB2KC
RE: [AMRadio] BW Coils Needed
I'm looking for a BW coil 15HDVL. Can anybody help ne on this one? George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Arthur E. Joly Sent: Friday, March 21, 2003 2:37 PM To: 'amradio@mailman.qth.net' Subject: RE: [AMRadio] BW Coils Needed I have a large group of Bud coils, is there a cross for the BW? Art N1RPN --- StripMime Report -- processed MIME parts --- multipart/mixed text/plain (text body -- kept) application/ms-tnef 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] Series capacitor equalizing resistors - now Johnson Power Plugs
Since they didn't have polarized outlets in the old days, the plug could go in either way. They had to fuse both sides for safety, and mandate the chassis to be grounded. Of course these days, the polarized three pronger guy is the best replacement ac line cord, with a fuse in the hot line only mounted on the rear chassis. George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Mark Foltarz Sent: Thursday, February 27, 2003 12:59 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] Series capacitor equalizing resistors - now Johnson Power Plugs Mike, You are absolutely correct about those fused line plugs. But I got to thinking about the philosophy behind those things. Way back when, proper installation of radio gear was specified as including a ground - both RF and electrical. If the operator made the installation correctly, the chassis was always cold. I think the engineers of that time believed that the operator was going to be responsible and install that chassis connection to a real electrical ground. Just a thought. Was operator forethought and responsibility part of correctly using those plugs or were they just plain dangerous? Yours, de KA4JVY Mark --- Mike Dorworth K4XM [EMAIL PROTECTED] wrote: Hi folks, just a little about the fused line plugs. You don't see them anymore because of their killing ability, which is very good. All you need is the fuse in the cold side of the line blown and of course the hot stuff goes in through and all the way back to the open fuse meaning the entire thing is full of juice waiting for a finger, might have been alright if they were polarized which there were not and of course the sockets were not either.. RIP with those literally.. 73 Mike K4XM - Original Message - From: Mark Foltarz [EMAIL PROTECTED] To: amradio@mailman.qth.net Sent: Wednesday, February 26, 2003 3:57 PM Subject: Re: [AMRadio] Series capacitor equalizing resistors Wayne, The other oddity of that period was of course the fused plugs that Heathkit, Johnson and other manufacturers used. Come to think of it, do you suppose the cord on that particular AT-1 is not original? I forgot if you described the schematic as specifically not having a fuse anywhere including the line cord. Yours, de KA4JVY Mark --- Sara Wayne Steiner [EMAIL PROTECTED] wrote: Mark The AT-1 manual says 450v, however mine runs about 460v. So , yes you are right, the series combo has a rating of 700v which is substantially more than what it sees. As I mentioned earlier, the AT-1 has no fuse (mine will soon have one ). My AT-1 was a $5.00 flea market item which came without the power xfmr. The corner of the chassis where the xfmr was mounted was covered with black crap where the xfmr obviously had a melt down probably due to a failed filter caps and no fuse protection! 73 Wayne, N0TE ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio __ Do you Yahoo!? Yahoo! Tax Center - forms, calculators, tips, more http://taxes.yahoo.com/ ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.455 / Virus Database: 255 - Release Date: 02/13/2003 ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio __ Do you Yahoo!? Yahoo! Tax Center - forms, calculators, tips, more http://taxes.yahoo.com/ ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
RE: [AMRadio] DX-100 vfo
DX100 VFO Troubles: Drifting up during transmission: Line voltage drop during plate voltage turn on with 600 watts pulled from the outlet may the problem. Check by first using the spot switch listening to the beat freq on the receiver. Then, turn on the plate voltage with transmitter fully loaded, and monitor the drift. If the filaments in the oscillator drops in voltage and slightly cools off the tube, the oscillator will drift! See if the oscillator returns to the original frequency when the plate switch is turned off. Cure: Use a variac to keep the voltage at 115 VAC during transmit. Or create a DC regulated supply for the filament string. Anything much lower than 115VAC and the emissions on the 12BY7 / 5763 and 6146s drops also. You may see this as gradual drop-off of grid drive during transmit... especially on TEN meters. I also rewired my VFO with heavy #14 copper. This was mechanically superior to the flimsy wiring that can cause drift and microphonics. Here is the big stability problem: Jumping during VFO freq adjustment on TEM meters. The VFO main variable has a rear ball bearing to support the cap shaft. It oxidizes and becomes erratic. I tried to clean it, but it was never perfect and always degraded again. I finally REMOVED THE DAM BEARING THING and the problem was solved. The bearing is not needed as I initially thought. The shaft is very stable without it. I hope some of this helps. George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of russ dworakowski Sent: Tuesday, January 07, 2003 1:53 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] DX-100 vfo To the group: I am having difficulty witha different VFO- a VF-1 or same as used in a DX-100. I know you guys are talking CE20- just a question- my VFO is tracking reverse in frequency- like when you go down in frequency on the display, it is actually going up in frequency. Is it possible that the end point adjustments are so far off that they could cause this? Russ From: Gary Schafer [EMAIL PROTECTED] Reply-To: amradio@mailman.qth.net To: amradio@mailman.qth.net Subject: Re: [AMRadio] Reply button got me... Date: Sun, 05 Jan 2003 14:46:35 -0500 Hi Larry and others, I too have a 20A. Have had several over the years. I found that to get good output on 40 meters that the 1625 has to be in very good shape. Being just a little weak makes a big difference. Also you need to adjust the padding coil (miniductor stock) that is across the 1625 tank coil in the vfo. You adjust it by spreading the turns on one end. If I remember right, the padding capacitor under the chassis needs to be peaked on 80 or 20 meters. The other bands are adjusted by adjusting the miniductor coils for maximum output. (It doubles or triples for other bands) It takes some messing with to get them right as the Q is pretty high. When you replace the top cover on the vfo things change so you have to compensate for that when adjusting. I watched the output of the transmitter (at less than full power) on a meter while adjusting the coils. Then watching how much it changes with the cover, you can get a feel for how much you need to adjust it in the opposite direction so it will be right with the cover on. Adjusting the coupling loop (knob on front panel) will detune the tank a little too on 40 meters. On one vfo that I have I tried slug tuned coils in place of the miniductor stock to see if they could be substituted. I found that the slug tuned coils in place of the miniductors did not give near as much output on the vfo so that was abandoned . I also tried to use a higher harmonic for 10 meters and shift the vfo with an additional padder capacitor (similar to what is done for 15 meters). I had a spectrum analyzer to watch all the harmonics at once but found that I could not get enough isolation. Some of the lower harmonics would end up in the output. I got it to work but tuning was very tricky and if not looking at the spectrum analyzer, the wrong harmonics would get right through the 20A. I gave up on that idea. I do have a vfo with the 10 meter kit in it. The crystal oscillator in it is run directly from the 20A's high voltage. When keying the transmitter that voltage drops some and the crystal oscillator starts to drift. I think that I tried running it from the regulated 105 volts one time but that dropped the output too low. I have never gotten back to it to try and solve the drift problem. Other than that it works pretty well on 10. I also have a Phase master vfo that I have yet to hook up. It is built on the 458 parts but rather than use harmonics they have separate crystals and heterodyne for the other bands. It may double on one band, I can't remember. The schematic of it is in Stoners SSB handbook. 73 Gary K4FMX Larry Szendrei wrote: Mike et. al., My CE20A has about 1/2 the output on 40M as it has on the other bands (160, 80, 20, 15) in spite of the fact that the CE mods to cure this
RE: [AMRadio] Re: Supply for PP 304TLs ??
Use 3000 Volts max. I use a pair in AB1 Audio. No... I did not pay $85,000 for it! I would not sell it for that either!!! Having to much fun. Anyway, No screen supply needed since they are triodes. Neutralization is a big must. For class C, I would use 304THs since the bias requirement is higher, and will give better efficiency and class C linearity when plate modulated. They do require plenty of drive however. The TLs versions are more linear for audio. Use a pair of THs for the class C, and a pair of TLs for the audio... if you have them. Audio phools are driving the price up on these. Glad I bought spares years ago! Have fun, George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Brian Carling Sent: Friday, November 01, 2002 1:33 PM To: amradio@mailman.qth.net; [EMAIL PROTECTED] Subject: [AMRadio] Re: Supply for PP 304TLs ?? Here you go DOn. This outfit sells transformers for building a 304TL amplifier. You can even buy the complete amplifier kit for $85,000 Hehe - yes guys, that IS $85,000 http://www.alumrocktech.com/prices.shtml Of course, it's a stereo audiophool amplifier. Looks like you could get a set of transformers for a mere $14,000 or so. On 1 Nov 2002 at 11:59, Merz Donald S wrote: By any chance is anyone running an HF amp or transmitter with push-pull 304TL tubes in the final? I have this homebrew here that uses this configuration. But the power supply it came with is in pieces and it is a mess. It was modified many times over the years by the builder and has been patched more than a Microsoft software product. So this thing needs a filament, screen and HV supplies. I can use some of the original parts. But for the HV, I don't want to use the original design because it is built around a 230V pole pig transformer and has lots of quirky design anomalies that I can live without (Anbody need a 125 pound pole pig? It'll give you 1700 to 2200 volts all day. The only drawbacks are that it is huge and weighs a ton). So I'd like to cheat and see how someone else is powering their rig to get some ideas. References to complete designs in any of the popular literature would be useful too. Can anyone help? 73, Don Merz, N3RHT ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
RE: [AMRadio] Magic lamp QRM
Slightly off topic: My neighbor has it all. Touch lamps, cordless phones, wireless keypads/mouses, and of course TVs. I get into all of it! Fortunately I can demonstrate NO INTERFERENCE AT MY QTH on anything (filters, toroids etc...). When I handed him printed info on the how and whys of RF interference and volunteered to help solve it... He threw the papers to the ground, started to call me @@$# and everything else in the book! At that point I stepped back from him and realized that I did not have to (or want to) help him at all. I told him that he could fix it himself and that I'm not legally obligated in any way... especially as long as he acts like that. After his performance, I said: It's your problem, not mine. I hope you enjoy my conversations. Case closed. However, I did mail him all the info certified receipt with his signature so he could do it him self since I will never step into his house again. Fortunately I do not hear any of his crap on my receivers (quad loops help?). Actually... I'm glad he acted like that. Now I know I will not get any more complaints, or have to spend the time with the jerk. George AB2KC 1KW AM -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Ed Sieb Sent: Sunday, October 06, 2002 12:48 AM To: amradio@mailman.qth.net Subject: RE: [AMRadio] Magic lamp QRM Those lamps are quite sensitive to RF fields. One of my neighbors has one of those wretched things. When he decides to use it, I just fire up the 100W rig, and key up a few random carriers in sequence. That sequences his lamp in varying brightness, and he eventually unplugs the thing in frustration. All my neighbors run RF trash producing junk. I have a contant +20dB over 9 roar of buzzies, warbles, farts and raspy hum all over HF. When ever I key up a nice carrier, I can hear all these signals shift around and settle back to their natural frequencies, when I unkey. It's quite amusing. Sending CW must cause quite some kind of disruption around my neighborhood. I can't wait untill I get my big 1KW big rig online. maybe that'll just blow up all that junk, once and for all. Ed, VA3ES ___ AMRadio mailing list AMRadio@mailman.qth.net http://mailman.qth.net/mailman/listinfo/amradio
RE: [AMRadio] Specific Bandwidth Limits for AM
The 3dB bandwidth spec may not be such a big deal. As a QRO fan of homebrew plate modulation and HiFi... let me explain: When the FCC (or anyone for that matter) specifies a bandwidth, the bandwidth attenuation by definition are the -3 dB points, usually with no mention of any other attenuation levels, or more specifically the shape of the response mentioned (other that -3dB). To be in spec one must be 3dB down at 3 kHz (not to noticable), however as an example, the 4 kHz point could be only -4dB!!! and still be OK since the skirts of the response are not specified. If a station receives your signal at +/- 5 kHz, he would have a hard time proving that the 3Khz point is not -3dB, especially if the signal is at +20 dB over 9 at the center of his dial! At this received signal strength and proposed -3dB points... the received signal of 3 kHz audio would be at +17 DB over 9 (-3dB)assuming at 10kHz bandwidth receiver. Even if the roll-off of the transmiiter provided -30 dB attenuation at 8 kHz, the receiver would still see an S-7 signal at +/- 8Khz! All this also assumes the receiver's -3db points are ignored when concidering the complaintent. Since most modern SSB receivers have very steep skirts, the hifi off channel received signal would be attenuated a great deal. Of course... the FCC measuring equipment is the spectrum analyzer with the inherintly flat broadband receiving display. Even using an analyzer... 3 kHz at -3db down is not an easy measurment to make (using voice)unless the transmitter is frequency swept while being monitored. I feel we AMers can proceed as we have been, using good engineering practices with no additional resrictions. This is really not out of line with what un-AMers have been seeing in their receivers all along anyway. So... not to worry. Just my .02 cents, George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Donald Chester Sent: Monday, August 26, 2002 1:00 AM To: amradio@mailman.qth.net Subject: [AMRadio] Specific Bandwidth Limits for AM Another point to consider... From the looks of Rinaldo's letter, the ARRL may be considering petetioning the FCC for specific bandwidth limits of 3 kc for SSB and 6 kc for AM. I see a couple of problems with that idea, besides the fact that it would limit phone signals to telephone-like communications quality audio. Even the SSB'ers are getting away from that, with the current interest in HI-FI SSB (an oxymoron?) First, even if you wanted to limit the upper high frequencies to 3 kc, it would be IMPOSSIBLE to maintain a flat response that high, without transmitting a signal bandwidth of at least 4 kc for SSB and 8 kc for AM, due to the rolloff characteristics of even the best filters. There is no such thing as an audio or rf filter with vertical skirts. Even the famous Collins mechanical filters are rated at -3/-30 dB points. Usually the -30 dB point is nearly twice the -3 dB point. To limit the significant bandwidth of a phone signal to 3 or 6 kc would require the audio to start rolling off at 2 kc or less. Secondly, this would render most presently-used vintage AM rigs and many older SSB rigs obsolete. Most AM rigs simply use a mic driving an audio amplifier which in turn drives the modulator. There may be some bypass capacitors across an audio transformer or two, and/or across the plate resistors of some of the low level audio stages, but this generates, at best (or worse, depending on what you think of the idea), a gradual rolloff of highs. Extremely sharp audio filters are possible (I have one), but not generally available, and to install them would require what would undoubtedly be difficult and expensive modifications to existing rigs. If this becomes mandatory, I suspect that many AM'ers will simply give up and say hell with it. So maybe the bandwidth proposal would not immediately kill AM as Docket 20777 would have, but in the long run it would have the same effect. Hopefully, knowledge of what is presently going down is not limited to members the AM Reflector and those who monitor the AM Window BB. There are still many members of the AM community who don't have computers or internet access. Also, I think many in tho SSB community would be allied with us on this issue, if they were aware of what may be about to happen. 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] Illegal 27 MHz dealers
No wonder those guys talk the way they do... with all that RF cooking their brains! Not to mention the nearby unknowing cars. They should be arrested. George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Monday, August 26, 2002 12:09 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] Illegal 27 MHz dealers If you dont believe it go take a look at davemade.com..amazing.Al/W8FAX --- 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
RE: [AMRadio] Fw: A rumor about ARRL
Gentleman, If the bandwidth limit of 3.5 KHz is to be implemented (unlikely I believe)... how unfair it would be in contrast to the broadcash stations that obliterate our hambands with super high power double sidebands with 10KHz bandwith playing music! For this reason and others, I think that this proposal (if real) is rediculous, not to mention that FM, TV and other wide band modes at the higher frequencies may be affected. If the FCC were real about this, maybe they would have previously implemented single sideband AM in the broadcast band so they could squeeze in twice as many AM atations, and phase out double sideband receivers in the general public. In fact... they could do and would have to do this in advance of changeing the transmitters, the same way the High definition TV format is getting it's foothold on us. If that commercial $$ power isn't enough to push bandwidth limitations, why would anyone care about ham radio? Besides, one could make a good case for using simple transmitters for emergencies that just happen to have double sideband emmissions, in light of the homeland security issues. Just some thoughts... George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of WILHITE, JIM Sent: Thursday, August 15, 2002 10:25 AM To: AMRadio Subject: [AMRadio] Fw: A rumor about ARRL I took the time to send a message to one of the directors mentioned in K1ZZ's message and here is his reply. I don't want to alarm people but now is the time to influence the direction of this proposal. I am hopeful the directors will listen to us. I think it gives a little insight into why the subject has arisen. Best we be on our toes. 73 Jim de W5JPW - Original Message - From: Tom Frenaye Sent: Wednesday, August 14, 2002 5:32 PM To: WILHITE, JIM Cc: Walt Stinson Subject: Re: A rumor about ARRL At 06:30 PM 8/14/2002 -0400, you wrote: Although I am not in your district, I wish to express my feelings that this can be a good thing or a bad thing depending on its proposal. I agree!! Quite a number of things have to be worked out before we go forward to the FCC. Any action won't be for many months (at least)! The rumor has stated that the maximum bandwidth be limited to 3.5 KHz. If this rumor is true, I want you to know I am deeply opposed and will file comments with the FCC as will many other members of the ARRL who are involved with AM operation. Can you substantiate this rumor please? Nope, can't substantiate it... Setting specific limits on maximum bandwidth was not discussed at the Board meeting as far as I recall. Just a rumor, something the Internet and some users like to start! But, now that the issue has been raised, are there limits to the bandwidth of different emission types that ought to be in our goals? The FCC often speaks to good engineering practice and I believe they would not like to hear a 5 khz wide SSB or RTTY signal, for example. -- Tom --- 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
RE: [AMRadio] Suggestions Please
The 1956 handbook has a very nice 500 watt class C all band 813 transmitter on page 198. I had that item in my hands many years ago. It was given to me by the High school I went to. I operated it and enjoyed it very much for a couple years. It also had the 811 modulators and the supplies in a rack. I did not know at that time that it was THE TRANSMITTER documented in the handbook until years later, when I found it in the 1956 handbook at a ham fest. When I opened the book and saw THAT transmitter on page 198, I almost cried! It was like looking at the gost of a long lost friend. I parted it out (kept the parts), and some of it is here and there in my 4-1000 rig, and the mod transformer is now in my DX100 (art-13 type). The final tank circuit is now my antenna tuner. Anyway... check it out. It is a beauty! Sometimes I just look at those pictures and think back when I was 16 yaers old on 11 meters with that thing (really)! My father insisted I get my license, so It was the start of my hamming. Every solder connection was right where I remembered it to be. Memories of the 813. George AB2KC -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] Sent: Monday, July 22, 2002 3:17 PM To: amradio@mailman.qth.net Subject: Re: [AMRadio] Suggestions Please HiThere are MANY examples of single band 813 amps in the old handbooks. I have a 1963 open now, and it gives a very good explanation, pics and componant list. Also shows a power supply and control circuits. Good luck..Al/W8FAX --- 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
