Re: [AMRadio] What do they mean?
figured it was time to start using my -real- name ;-) check out qrz.com that, and W0VY(?) in Mississippi - it's so we don't get confused. -- 73 = Best Regards, -=Geoff/W5OMR=- - Original Message - From: "Tommye & Jim Wilhite" <[EMAIL PROTECTED]> To: Sent: Monday, November 18, 2002 15:59 Subject: Re: [AMRadio] What do they mean? > Hi Jeff: > > What is the "Goeff" business? Did you get a big raise? > > Jim > de W5JO > > > > > -- > > 73 = Best Regards, > > -=Geoff/W5OMR=- > > ___ > AMRadio mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio > >
Re: [AMRadio] What do they mean?
> I dunno. Frankly, I'm looking for a "4-pill job" myself! I need an amp with > four MRF 455, or 454, for my 10M mobile rig. Just because these amps were > initially targeted for CB use doesn't mean we Hams can't use 'em > legitimately. Some amps, such as the "RM" brand made in Italy, is actually > of very high quality, and is truly broadband, with coverage from 3 to 30 > MHz. Just the thing for your FT817. With four MRF454's, they require about > 20W drive for about 300W PEP out, and they are properly AB1 biased. There's a ham store, that sells the "Golden Eagle 377/XL" two transistor amp. Why limit yourself to MRF 454/5's? Why not the 2SC2978's? A pair of those, with about 20w of drive is 300 to 500w out, depending on the band. > Yeah, so the CB'ers are buying them. It's a problem, especially when they > buy the junk that runs class C. > Either you have a free market, or you don't. > > When linears are outlawed, only outlaws will have linears. Same can be said (and has!) for AM kW's. -- 73 = Best Regards, -=Geoff/W5OMR=-
Re: [AMRadio] Supply for PP 304TLs ??
Subject: [AMRadio] Supply for PP 304TLs ?? > 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. Sounds like someone I know (not me) :-) > 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). Screen Supply? for a pair of Triodes? > 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? a regular Choke-input supply can't be simpler... I think even I could probably muddle through one, now. ;-) 73 = Best Regards, -=Jeff/W5OMR=-
Re: [AMRadio] UTC CG-305
> >Sorry for the erroneous post. > > > >In all my catalogs, CG refers to audio transformers. Are you sure of the > >number? Yup - it's a CG-305 - verified it this morning. Odd, though - Someone else said that the output was High voltage 2400-1750-0-1750-2400VAC, DC voltage 2000/1500, 300 mA continuous yet the critter is labled (engraved, even) 3500 and 4800. That's -gotta- be across the entire secondaries. Half of that (what you get when you measure from CT to outside winding) fall exactly half of what the transformer has engraved on it. > CG means "commercial grade". It applies to both audio and power > transformers. This line of transformers was originally designated "PA" > (public address). The CG numbers and PA numbers are the same, and the > electrical characterists are usually t he same, but they may be physcially > different. The changeover took place in 1948. > > CG (and PA) is UTC's mid-line. It includes the CVM and VM series modulation > transformers. Their top line was the LS series. There are audio and power > LS transformers as well. LS transformers were very expensive, even before > WWII. LS audio transformers are rated as hi-fi and suitable for broadcast > service. > > Their lowest grade transformers are the S series. These are typical "ham > radio" qualty transformers, with marginal power/voltage ratings and mediocre > audio performance. > > I'll look up the transformer when I get home f rom work. I'd appreciate it, Don. I'm reasonably sure the previous post is correct, though. 73 = Best Regards, -=Jeff/W5OMR=-
[AMRadio] UTC CG-305
Looking for this transformer on the internet proved useless. Google let me down :-( Does anyone have an old UTC Catalogue and can tell me what the current ratings on this plate transformer are? The two secondary windings are 3500v and 4800v. I believe it to have 110/220vac inputs. there are 6 lugs on the input, and 5 on the back (one center-tap) 73 = Best Regard"S" -Jeff/W5OMR-
[AMRadio] 75m AM Contact 12 September 2002 K4KYV es W5OMR
> > > >Callsign: WA4D Class: Extra Codes: HAI USA > >Name: MICHAEL E WHATLEY > >Addr1: 5844 DORIS DR > >Addr2: ALEXANDRIA, VA 22311 > >Country: USA > >Effective: 24 Aug 1995 Expires: 24 Aug 2005 > >Lookups: 1113 > > > Yes, I remember him well. Don't remember the retiree stuff, but he was a > QRM'er and a jammer. He would come on a frequency with SSB and announce > that the occupants had 10 minutes to terminate their QSO. If they didn't > comply, he would come on with an exceptionally loud and distorted signal and > jam the frequency until everyone was gone. "Dog" was his phonetic for > wa4"D". He tromped over AM and SSB alike. Like many such individuals, he > was widely detested, but also enjoyed a cult following. This was in the > days when there was practically no FCC enforcement, but somehow he raised > his profile high enough that they took proceedings against him. I forget > what the outcome was, but he was not heard jamming after that. Yea, I remember all that, too. Seems I had just gotten on the air, back in 1984 when he was in his "heyday". It was good to contact you again tonight, Don. Sorry for the fuse blowing in the middle of the transmission :-) I have -got- to re-wire that shack. I've talked extensively with John/WA5BXO about the modulation reactor that you and he built out of a pair of 12HY chokes. What I did here, was to string four chokes in series - 2 of which are [EMAIL PROTECTED], 1 is [EMAIL PROTECTED] and the 4th is [EMAIL PROTECTED] So, essentially I've got [EMAIL PROTECTED], which is then capacitivly coupled with two [EMAIL PROTECTED] capacitors. Rig here is a pair of 250TH's in push-pull, link coupled and they're modulated by a pair in Class B, using that old RCA Open frame modulation transformer we discussed. I agree - the application that those small-ish pieces of iron were built for doesn't add up, according to the nomenclature plate on those critters. All the ones I've seen are 5,500ohms 1:1 ratio and the secondary current is stamped as 0.198ADC. I'm still trying to figure out why though, they would use A2 emission instead of straight CW. Seems that there would be more cause for a loss of signal, with phase shift and band conditions, etc. When nothing else works, CW does. I'll go out and look for some more 120v 30amp line fuses. Not only is the rig on that circuit, but so is a window unit for the house. Apparently I hit an audio peak at the same time the compressor kicked in. ka-Blewy! The whole shack went dark. CUL Don, and thanks for the QSO. 73 = Best Regards, -=Jeff/W5OMR=-
Re: [AMRadio] Subbands and FCC
> why did Riley, et crew give > >OO notices to three hams for "operating phone in the CW sub-band of 160m"? > > > >Dennis Clouter(sp?) was one of them, and the three are listed in the > >archives of the "FCC Enforcement" logs. > > There are no government-mandated subbands on 160. There is a "band plan" > published by ARRL. The story I heard was that the stations in Houston were > firing up on top of existing cw QSO's in the "dx window" and either ignoring > calls that the frequency was in use, or actually saying over the air that > they didn't care if they QRM'ed the cw stations. Riley sent them a letter > saying they could be cited for deliberate interference, and not following > good amateur practice, since it appeared that they knew the cw stations were > there. > > This incident instigated a petition to the FCC to create a cw subband on > 160. So far, the FCC has not acted on it, and at the FCC forum at Dayton, > they left the impression that they would not be inclined to adopt the > proposal. I never heard the actual story, either. That one sounds (unfortunately) plausible. thanks, Don. 73 = Best Regards, -=Jeff/W5OMR=-
Re: [AMRadio] Subbands and FCC
> I say let's go the way of Canada and most of the rest of the world. Get rid > of subbands altogether - by mode AND by licence class. Let all the bands be > like 160 is now. It has worked pretty well without subbands the past 20 > years or so since LORAN restrictions were lifted. Don, if 160m is all modes, all over the band, then why did Riley, et crew give OO notices to three hams for "operating phone in the CW sub-band of 160m"? Dennis Clouter(sp?) was one of them, and the three are listed in the archives of the "FCC Enforcement" logs. I point out Dennis, because he's from the Houston area, and he's also the first time I was 'exposed' (pardon the pun) to 10GHz. 73 = Best Regards, -=Jeff/W5OMR=-
[AMRadio] Technical Question
I've got a 20MHz Hitachi Oscilloscope, model V-212. Recently, the horizontal sweep disappeared. Does anyone have any info on one of these, or better yet, a manual for one? 73 = Best Regards, -=Jeff/W5OMR=-
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. > > Jeff - > > I recall someone referred to as the 'dog' back in the early 80s who > ripped this off and instead used 'No lids, no kids, no retirees' or > such. Fortunately he was removed from the bands at some point for his > behavior(far worse than his intro), and fortunately - he operated SSB. > Think the call was WA4D? Probably still out there, somewhere Callsign: WA4D Class: Extra Codes: HAI USA Name: MICHAEL E WHATLEY Addr1: 5844 DORIS DR Addr2: ALEXANDRIA, VA 22311 Country: USA Effective: 24 Aug 1995 Expires: 24 Aug 2005 Lookups: 1113 Appears as if he's still licensed. Active? I dunno. 73 = Best Regards, -=Jeff/W5OMR=-
Re: [AMRadio] No Kids, No Lids.......
> 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. Think I found something but it's certainly not definitive... === SPACE CADETS _ VERSION 1 CQ CQ CQ - No Lids, No Kids, No Space Cadets -- "Attributed to the late W2OY, Mike, back in the late 40's on 75 meters when it was a Class "A" only band. Mike was known around the northeast for this everytime he called CQ." >From Bob Wilder, W4RHW SPACE CADETS - VERSION 2 If you didn't hear W2OY, you missed a one-of-a-kind. Actually, he said, "CQ CQ CQ. No kids, no lids, no school bus riders or space cadets. No kings, no queens, no jacks. This is the NO PHONETICS station, W2OY." I heard that hams in his town got so worked up over his antics, that somebody sneaked into his yard one night and drove a pin through his coax, but I have no way of knowing whether this story is true. -- From Bill, NG3O === I'm not sure the full text is found, yet... oh, well... it was fun to remember. 73 = Best Regards, -=Jeff/W5OMR=-
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"
Re: [AMRadio] 500.00 Rangers
> >The Parts Collectors Creed: "Tis better to have and not want, than to want > >and > >not have." > > > The way I heard it was: "It's better to have it and not need it, than to > need it and not have it." (From John Mohn W5MEU). Close... I stumbled across some of his old "Radio Parts Collectors Association" and it says: "It is better to have and not need than to need, and not have."
Re: [AMRadio] 500.00 Rangers
> BTW, I enjoy very much the stories you related Jeff (I've broken a 75th and dropped > 250th *ouch*), and the large wealth of knowledge imparted on this list. Getting to > learn from the actual experiences, vastly different knowledge bases and types of > people on here truly adds to my rather lacking knowledge in many areas. No sarcasm > intended, but I have a junkbox which is the size of a garage. Oh, wait a > minuteit *is* my garage! hehehe... I can relate. my *shack* is a closed in car port. boxes of 833's, the AM Final, a BC-610 E model, 2 boxes of plug-in coils for the 610, a Viking II, and SX-73, 3 shelves on one wall full of transformers, oil-filled caps, a box of big tuning caps, a couple of dozen of cigar boxes full of fuses, xtals, tubular electrolytic capacitors, switches, potentiometers, a few reel-to-reel tape machines, some old dead cassette machines, some working, some of everything, a lot of nothing. To most people it's junk. To a builder, it's paradise. To an 'appliance operator', it simply looks like there's not enough desk space (of which I have three in that room) to place their Yea-Com-Wood's and "2-holer" amps. The Parts Collectors Creed: "Tis better to have and not want, than to want and not have." 73 = Best Regards, -=Jeff/W5OMR=-
Re: [AMRadio] 500.00 Rangers
> > Yes I know, $500 rangers. But look, you don't have to buy it! Just how > > bad do you want one anyway? > > This is the main point. No one is being forced to pay anything. Strictly a > choice. > > >I have 2 that I paid $25.00 each for. > > Money in the bank collecting interst? You bet. To be certain, I would not > > pay $500 for any Johnson Ranger, not even NIB. But I already have 2. > > Would you sell them for $25? For 'the good of ham radio'? If I find a gold piece > in the dirt, should I give it to someone else because I was in the right place > at the right time and found it? That seems to be what some would like us to do. I don't know about you, but I didn't get into Ham Radio, and subsequently AM because I wanted to make a business out of my Radio Hobby. Example: I needed some 872's. I know of a Ham who had some, and he offered them to me. A mutual ham friend needed some 8008's. Due to some misfortune, what was to be a pair of 872s turned out to be one (the other was cracked). So, the guy who wanted 8008's was asked if he had any spare 872's. He did. I only wanted 1 more, but for the trouble of traveling to Ham B's house (which was on the way) and dropping off the 8008's, I was rewarded with 3 (three) 872's. And I got them ... because they had them. John Coleman was putting his 250TH rig back together. As he was tightening the grid cap on one, I said "John, don't tighten the screw too tight you'll (sickening sound of glass breaking around the small, thin grid pin) "CRACK!" ... break one...:-( I was going back to John's the next weekend, and I had a spare or two... so I brought all my 250TH's I had, at the time - let him pick and choose which one he wanted, and he put one in his rig, and off it went. No money. Why? Because I had spares, because John needed one. Because John is a friend I made, through Ham Radio. And a truer friend can not be found. Jim Candela/WD5JKO and Scotty/W5CCV came down from Austin, TX this week because I was having trouble neutralizing my rig. Still am, but that doesn't excuse the FACT that Jim and Scotty were HAM enough to come help another ham who's back was up against a wall over a problem that shouldn't be a problem (but still is :-< ) Tony Cypert/W5OD (the guy who started this) is in the process of building a rig with a 450TH in the final. I had gotten a filament transformer from Ronnie/W5SUM for my 450TL modulator project, and I had an extra 7.5v @ 12amp filament transformer, laying around. At a ham's place I did a deal at, I dropped off the filament transformer for Tony (no charge, and it's 150 miles closer to him, than being here) because it was 'extra'. THIS, gentleman, -is- the true spirit of Ham Radio. Where have all the HAMS gone? What ever happened to HomeBrewing? Johnson Rangers, indeed! Xtal -> 6C4 -> 12BY7 -> pair of 6146's = 100w. Oh, wait - I know... There are no junk boxes anymore, because people would rather BUY something that was commercially made, 60 years ago... I'm not in this business to make a living (aka: be a Feather Merchant) I, too, want to promote Ham Radio, and especially AM. But if I'm going to have to start paying the prices being asked for things like 250TH's (anywhere from $150 to $300 PER TUBE!) then I might as well turn in my ticket and exchange it for a re-sellers license. There's my .02c -=- keep the change. 73 = Best Regards, -=Jeff/W5OMR=-
[AMRadio] 40m
Anyone in the 5th call area that can get on 40m during the daytime?? How about a gathering on Saturday afternoons and Sunday mornings? Say around 9am Sundays, and 2 or 3pm on Saturday afternoons (family ties permitting, of course) 73 = Best Regards, -=Jeff/W5OMR=-
[AMRadio] W5AMI?
W5AMI, this is W5OMR calling. Brian, are you lurking around here, somewhere? any one else in the 5th call area, that can get on 40 or 75m in the afternoon/evening times? 73 = Best Regards, -=Jeff/W5OMR=-
Re: [AMRadio] changing subject (testing for Brian)
I've got two in the que to go that way, but they're still here. this is a reply to a message from me, that showed up. Regards, -Jeff - Original Message ----- From: "Jeff Edmonson" <[EMAIL PROTECTED]> To: Sent: Sunday, August 18, 2002 08:08 Subject: Re: [AMRadio] A.R.R.L. es AM mode > Thanks, Tom! > > Regards, > -Jeff > - Original Message - > From: "K0PJG" <[EMAIL PROTECTED]> > To: > Sent: Friday, August 16, 2002 12:44 > Subject: [AMRadio] A.R.R.L. es AM mode > > > > A discusion is ongoing under Talk es Opinions on QRZ.COM. Please do drop by es > read/give your opinion on minute 64 > > of the last Board meeting. > > > > 73, > > > > > > Thomas F. Fischel > > 8274 Cullowhee Mountain Road > > Cullowhee, Nc 28723 > > [EMAIL PROTECTED] > > > > To view Collins equipment ; > > http://www.qrz.com/callsign/k0pjg > > > > > > --- StripMime Report -- processed MIME parts --- > > multipart/related > > multipart/alternative > > text/plain (text body -- kept) > > text/html > > application/octet-stream > > 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 mailing list > AMRadio@mailman.qth.net > http://mailman.qth.net/mailman/listinfo/amradio > >
Re: [AMRadio] A.R.R.L. es AM mode
Thanks, Tom! Regards, -Jeff - Original Message - From: "K0PJG" <[EMAIL PROTECTED]> To: Sent: Friday, August 16, 2002 12:44 Subject: [AMRadio] A.R.R.L. es AM mode > A discusion is ongoing under Talk es Opinions on QRZ.COM. Please do drop by es read/give your opinion on minute 64 > of the last Board meeting. > > 73, > > > Thomas F. Fischel > 8274 Cullowhee Mountain Road > Cullowhee, Nc 28723 > [EMAIL PROTECTED] > > To view Collins equipment ; > http://www.qrz.com/callsign/k0pjg > > > --- StripMime Report -- processed MIME parts --- > multipart/related > multipart/alternative > text/plain (text body -- kept) > text/html > application/octet-stream > 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] Neutralizing a push-pull final.
I've been trying to get my old 250TH rig back on the air. for the most part, I've been rather successful. but, I've run into a kink... I can't seem to neutralize the final. The exciter is a Johnson Viking II - plenty of drive, and at the same time, variable. This is good. I'm not gonna have my fingers in there, twisting on the big disks of the neut. caps while there's 100w of RF flowing through there :-) but, things just aren't as they should be - or so it seems. I was talking to John/WA5BXO about this, and he suggested putting it here in the reflector. Here goes. == well, I'm more frustrated than I was before... removed the B+ lead to the final, got my meter out, connected a clip lead from the center conductor of the coax connector of the link output to a diode, then to the meter probe, and a clip lead from the shield of the coax to the other meter probe. We're ready to measure output voltage! And, measuring voltage wasn't a problem. the problem was, that every time I thought I was getting the output down to (as low as 50!) millivolts, I'd run the main tuning condenser through resonance again, and the voltage would shoot back to nearly where it was, when I started. I thought "well, maybe the grid current through the relay is causing problems." So, took another clip lead from the grid bias voltage input on the back of the final, and ran it to ground. ==(insertion)=== (John came up with the 'relay' idea. quite simple. Instead of a bias supply, attach a relay from the bias point to ground. The relay should require about the same amount of current to close, as do the tubes. In the case of 250TH's, around 90mA for 2) (continuing) Fired up the exciter again, (grid meter don't work, unless it's got a ground return) and ran the excitation level back down low, and started again. Same thing - I'd get to a point where it looked low, then I'd run the final capacitor through resonance again, and the output would go back to nearly where I started from. So, I chased that down, for another hour. I never got the output voltage from the link lower than a volt or two DC (as rectified by the diode) and as a result, while I'm not seeing a dip in grid current anymore (with no B+ applied) I am seeing a difference of about 100mA's between dip and resonance (max power out) What the heck is going on? -=-=-=-=-=-=-=-=- that was the first time I tried. I've since been told, that there needs to be a load, on the output of the link, so I plugged it into my 50ohm dummy load and measured the output there, at the dummy load. but, I got the same results. Here are the facts: The final uses Cross Neutralization. The final "C" section is a B&W Butterfly tuning capacitor Neutralizing caps are on the end of it. Thoughts? Regards, -Jeff
Re: [AMRadio] Trade nos Stancor A-3894 poly-pedance 125 watt modulation xfmr
Wish you were closer, Bob - I've got something here like that, too, but I'm not gonna pay for shipping from San Antonio to NC... Regards, -Jeff - Original Message - From: "Bob Login" <[EMAIL PROTECTED]> To: Sent: Saturday, August 10, 2002 21:39 Subject: 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 : : ___ : AMRadio mailing list : AMRadio@mailman.qth.net : http://mailman.qth.net/mailman/listinfo/amradio : :
Re: [AMRadio] what to use for a mod reactor???
: >...just in case you're not sure how to connect it, I tie one end of the : >modulation transformer (that WAS going to the B+ supply) to ground. : >The other side is connected to a large capacitor (5uf @ 5kV) on the Final : >side of the B+ line to the final. : > : >So, from the B+ supply, attach to one side of the choke, the capacitor to : >the other side, that's connects to the mod xfmr and then B+ from the choke : >to the final. This shunts the DC off of the secondary of the modulation : >transformer, allows the transformer to react more linearly, and prevents : >core saturation on the secondary of the modulation transformer. : >More Core in the transformer = broader range of frequencies, generally : >speaking. : : Actually there are 3 ways to connect it. The above corfiguration has the : disadvantage that one winding of the modulation transformer is always : grounded, putting high voltage stress on the insulation between windings. the alternative to that, is to put another capacitor from the low-end of the modulation transformer, to ground. Just to be clear, Don - I'm shunting, entirely, the DC off of the secondary of the modulation transformer. Capacitivly coupling the transformer coupled audio to the B+ line, on the 'high' end (or the tank circuit end) of the reactor choke. : You can use a string of filter chokes in series, but that is bulky, and : sometimes power supply chokes have so much stray capacitance that you lose : high frequency response. Ask me or John, WA5BXO sometime to explain how we : made a nice compact mod reactor @ 30 Henries using two identical 12-Henry : filter chokes. I've been there, seen it, held it in my hands, when I went there and helped John put the rig together, when he bought the trailer and put it on the property there at Delta Plaza. Then the floods came in, and floated the trailer, and bounced it around the pylons under I-45 where it crosses Spring Creek, finally cracking the trailer open like an egg, with the force of the water. : With so many old tube type BC transmitters being junked as they are replaced : by solid state units, modulation ractors and transformers should not be that : hard to find. I need to keep looking, then. I'm just trying to get something going, with what I've got. I -have- been working on a modulator deck. Building it up, using the configuration as a combination deck, that'll handle either 250TH's or 450TL's. some pictures (so far) of the rebuild are at http://w5omr.shacknet.nu:81/~w5omr/250-rebuild/ 73 = Best Regards, -=Jeff/W5OMR=-
Re: [AMRadio] what to use for a mod reactor???
: I been readin as much as I can about modulation reactors... and I am going : to try to use a common inductor in place of one... it's the same thing. A fixed value Choke - something like 40 or 50 Henries at *at least* the current you're drawing in the final tank circuit. : I have one huge inductor that is about twice the size of the VM3 mod iron : I plan to use... I'm not sure of its inductance... I think it may be : 'high' current but got to check... I don't have such "big" iron around here, but several smaller chokes (10Hy @ 500mA type) that I'll be stringing together, at right angles to each other to make up 50 or so Hy at 400mA (I think the smallest I'll be using only has a max of 400mA @ 20Hy) : I also have more mod iron laying around... possibly use a mod tranny for a : reactor And, just in case you're not sure how to connect it, I tie one end of the modulation transformer (that WAS going to the B+ supply) to ground. The other side is connected to a large capacitor (5uf @ 5kV) on the Final side of the B+ line to the final. So, from the B+ supply, attach to one side of the choke, the capacitor to the other side, that's connects to the mod xfmr and then B+ from the choke to the final. This shunts the DC off of the secondary of the modulation transformer, allows the transformer to react more linearly, and prevents core saturation on the secondary of the modulation transformer. More Core in the transformer = broader range of frequencies, generally speaking. : Any ideas on the ins and outs would be appeciated... : : I'm going to finish this rig if it kills me... or drives me crazier than : I already am... heeheeheehee hope that helps. 73 = Best Regards, -=Jeff/W5OMR=-
Re: [AMRadio] V10 in GSB-100?
: Just acquired a Gonset GSB-100 transmitter over the weekend, and : everything appears to be in order with it except for the crystal : oscillator tube (V10). The book lists a 12AT7 in this location, but the : book's schematic and the transmitter itself show a 12AV7 instead. WHich : is correct? These two tubes aren't nearly the same, but on the other : hand the transmitter works, so should I just not worry and be happy? I don't know... There's not a whole heckuva lot of difference in the 12AU7 and the 12AT7, but I'm not sure what the differences are... So, I'm going Googleing (http://www.google.com) Back, and I came up with this... for a 12AT7 HIGH-MU TWIN TRIODE Specification and max ratings(*) Filament Voltage 6.3-12 V Filament Current 300-150 mA Plate Voltage (max) 300 V Plate Current (max) 15 mA Plate Dissipation (max) 2.5 W Screen Voltage (max) --- V Screen Current (max) --- A Screen Dissipation (max) --- W Pin Element Unit 1 Plate (Anode) Triode 2 Control Grid 2 3 Cathode 4 Filament 5 Filament 6 Plate (Anode) Triode 7 Control Grid 1 8 Cathode 9 Filament Center-Tap 12AT7 Standard version of this double triode in 9 pin miniature package. 6201/12AT7WA Milspec version of the type 12AT7. Genuine versions of these have extra thick mica wafers to help eliminate microphonics. Some have extra support rods which give even more stability. Late versions by Philips/ECG, etc don't have this feature. They really shouldn't be called 12AT7WA's (or WB or WC). 6679 Mobile communications version of the 12AT7. This tube is supposed to be able to maintain rated output/transconductance over a +/- 20% filament excursion. Otherwise, this tube is the same as type 12AT7 7728 Premium instrument grade tube made only by CBS/Hytron. This tube has heavily plated gold pins. ECC801/ECC801S Super premium grade tube made by Telefunken. The "S" version is a special selected tube. for a 12AU7 Specification and max ratings(*) Filament Voltage 6.3-12 V Filament Current 300-150 mA Plate Voltage (max) 330 V Plate Current (max) 22 mA Plate Dissipation (max) 3 W Screen Voltage (max) --- V Screen Current (max) --- A Screen Dissipation (max) --- W Pin Element Unit 1 Plate (Anode) Triode 2 Control Grid 2 3 Cathode 4 Filament 5 Filament 6 Plate (Anode) Triode 7 Control Grid 1 8 Cathode 9 Filament Center-Tap The 12AU7 is a medium mu multi-purpose double triode in a 9 pin miniature package. There are several different versions of the 12AU7. Below are most of the commonly known variations of the 12AU7. 12AU7/12AU7A The only difference between the 12AU7 and the 12AU7A is the "A" version can be used in series string filament circuits due to it's controlled warm-up cathode. Otherwise, there is no difference. 6189/5814 Both of these are "milspec" versions of the 12AU7. They may also be marked with 12AU7WA. They both have thick mica wafers which give the tube extra rigidity which minimizes any microphonic problems. Their cathodes have been specially designed so they can withstand many on/off cycles and long periods in cut-off without any degradation of performance. The 5814 has a slightly higher filament current demand than the 6189/12AU7. Some (not all) Sylvania Gold Brand versions of these tubes have gold plated pins. 5963 This tube makes a decent substitute for the 12AU7 as the characteristics are almost the same. The 5963 has a slightly lower plate voltage rating compared to regular 12AU7. The 5963 has a max plate voltage of 250V while 12AU7 has a max of 330V. This tube has a specially designed cathode which can withstand long periods of time in cut-off without hurting the tube. 7730 This is a premium version of the 12AU7 made only by CBS/Hytron. This tube has very low noise characteristics and heavily plated gold pins. These were intended for critical test instrument applications, but due to their superior low noise performance, these make excellent choices for audio applications. 6680 This is the mobile communications version of the 12AU7 which can withstand +/- 20 % variations in filament voltages without any degradation of tube performance. ECC802/ECC802S These are "premium" 12AU7's which were marketed by European manufacturers. I don't think that there was any difference in manufacturing technique, to create these, rather they are just specially tested 12AU7's that exhibit very low noise/microphonics and matched sections. 7316 This is an Amperex tube that was a premium grade 12AU7. and, while I was at it, I went ahead and got the 12AX7 info... 12AX7 Specification and max ratings(*) Filament Voltage 6.3-12 V Filament Current 300-150 mA Plate Voltage (max) 330 V Plate Current (max) 6 mA Plate Dissipation (max) 1.1 W Screen Voltage (max) --- V Screen Current (max) --- A Screen Dissipation (max) --- W Pin Element Unit 1 Plate (Anode) Triod
Re: [AMRadio] Audio response and Long distant QSO's (was: Suggestions Please)
: : I'm hoping that Don can come in here, and remind me how it is/was : >he was peaking the audio at around 3kc, and then rolling the whole thing : >off at 3.5kc (or slightly higher). And, what's the bottom end? : > : : I do it by using a rising pre-emphasis between curve in the mic preamp, : starting at 800 cps and peaking 8-10 dB at 3 kc/s and above.Also, I use : a D-104 mic (for highs) and a dynamic mic (for lows) mixed together in : phase. The low-pass cutoff is accomplished using passive L-C filters. With : the flip of a switch I can choose between a gradual hf cutoff filter at 5-6 : kc/s, a very sharp cutoff filtor at 3400 cps, or no lowpass filter at all. : The bottom end goes down to 30 cps or so, but the scope shows visible : distortion on a sinewave below about 40 cps. and at those low frequencies, it's rather difficult to hear the bass, anyway. So, would you say that decent (someone define "hi-fi" Ham AM Audio, please) audio could be well received from 50Hz to 4kHz, or less (on the High end)? : With the 3400 cps filter in the circuit, the response curve is flat from 40 : cps to 800 cps, then rises steadily up to about 2 kc/s and begins to : flatten off beyond 3 kc/s, but hits a brick wall at 3400 cps. I bought the : filter at a military surplus store in Washington DC back in 1973 ( I wish I : had purchased half a dozen of them). There is virtually no attenuation at : 3300 cps; at 3400 it is over 25 dB down, and at 3500 cps you can't detect : the signal on the oscilloscope. : The only other filter I have ever seen that has that sharp a cutoff is one : designed by W2WLR that he sent me to evaluate. On the air, when tuned onto your signal, you've got some good, loud CLEAN audio, Don. Your signal isn't as wide as some of the others who are trying to put 10kHz of signal into a 6kHz bandpass. Please, everyone - excuse the comparison, but it does indeed sound a lot like the 'rack audio' SSB guys who are adding pre-emphasis, tone-tailored audio into their SSB rig, AFTER the Balanced modulator, to get a 'wider' spectrum to pass their audio through, taking up sometimes MORE than the conventional AM signal space, and while doing that, complain that "that ol' AM mode takes up too my bandwidth". Just some thinking, while sitting here at 02:18 (insomnia is a bitch!), does anyone think that the rack-audio guys are working on their radios as they are because they hear the AM'ers with decent audio, and are trying to mimick them (of course, without admitting that the AM mode has superior audio -smirk-) or is it because they see that AM is still allowed on the bands, they know damn well how wide an AM signal is, and figure (in their infinite wisdom) that "well, if the AM'ers can do it, than WE CAN TOO!" They just don't remember the AM/SSB wars from years ago. Back then, the fight was over not which MODE was better, but which mode was better for HAM RADIO. The SSB'ers argued that their signal took up 1/3 of the space, of a conventional AM signal. They're right. The AM'ers said that the resulting audio of a SSB signal, at 2.1kHz, was like trying to push an elephant through a keyhole. We were right about that, too. Now, the SSB'ers are using up to 10kHz of audio, AFTER the balanced modulator and when I hear a comment from someone who's fairly connected with Riley and the FCC that says that between Bob Heil and Riley Holingsworth, they're talking about limiting signals to 3kHz (that would be for SSB *only*, I hope!) and I share this informatoin, only to get told "you don't know what you're talking about". Am I the only one that see's the handwriting on the wall? I'm not trying to be a handwringer guys, but hey - something could be happening and party, it might be the blame of the wide-band, "hi-fi" AM audio that 'some' of the AM community runs. Yes run decent audio, yes make air-checks, yes homebrew it all! LIMIT the total bandwidth, so that ALL amatuers can get along on the same band(s). : One thing that is often overlooked is that the audio system capability needs : to extend one octave above and below the intended frequency response of the : program material, to minimise phase distortion effects. This is per : information in the United Transformer Corp. catalogue. For example, if you : intend to transmit high quality voice audio from 100 to 3500 cps, your audio : chain from the mic through the modulator stage needs to be as flat and : distortion free as possible from 50 to 7000 cps. Good "communications" : quality audio 300-3000 cps would require the transmitter to be capable of : 150-6000 cps (that is almost exactly the audio specification of the BC-610). Interesting about the '610... when I fed the output of the Solid State Audio Driver straight to the grids of the 100TH's in the W5MEU "E" model, the difference in audio was (according to others) tremendous, compared to the BC-614 Speech-amp, and that's one that John himself had modified for audio. : Any limiting of frequency r
Re: [AMRadio] Audio response and Long distant QSO's (was: Suggestions Please)
Subject: Re: [AMRadio] Audio response and Long distant QSO's (was: Suggestions Please) : : : Jeff: You are too logical!! Wideband for strong signals, narrowband for : weak signals. Almost all AM signals in Nebraska are weak so I : guess that makes me "narrow minded". By the way, there are several : systems that automatically adjust either audio or IF bandwidth : depending upon signal strength (AVC) or signal to noise ratio. : I have used both until DSP came along. Good luck in your discussion. Charlie, (and Bill and others) the whole point is, why are some hams trying to sound better than most broadcast stations? If you listen to most broadcast stations, there's some distortion there that you'd hope you'd never see on your Ham station, but those stations are TRYING to pass frequencies lower than 50hZ - in fact, they're trying to pass as low as 30hZ and that requires some BIG iron, UNLESS you're using PWM/PDM. Methinks most mic equalizers could use some tweaking, and some rolling off of the bass. 73 = Best Regards, -=Jeff/W5OMR=-
[AMRadio] Audio response and Long distant QSO's (was: Suggestions Please)
: If you have to ask, then you are probably using too much. If you are : listening, you probably aren't using enough. If all you think about is : comparing AM to SSB, then you are just looking for a silly argument. Trust me, Bill, this is not someone "trolling" for a fight in a group. I'm serious when I ask, though - what's the purpose of trying to run audio, starting at 50Hz, on a noisy HF band like 160, 75 or 40m? honestly, from across the nation, those transmitters who have that much low-end response are the same people who want that low-end response enhanced, and in periods of QRM/QRN and selective fade, it's more of a determent to be able to copy, than an enjoyable, enhanced audio performance. I'm absolutely sure that the later is the goal intended, but for talking cross-country on noisy bands, SORRY!, it's just not gonna happen. Now, it's possible to have GREAT audio and still filter and tailor the audio so that it's not out of the passband, such as that of Don Chester, K4KYV. I'm hoping that Don can come in here, and remind me how it is/was he was peaking the audio at around 3kc, and then rolling the whole thing off at 3.5kc (or slightly higher). And, what's the bottom end?
Re: [AMRadio] Suggestions Please
In case some of you have forgotten, or haven't seen it, there's some good technical discussion concerning driving Class B modulators, the inherent distortion, and one proposed solution for getting away from it http://www.qsl.net/wa5bxo/driver1.html Regards, -Jeff
Re: [AMRadio] Suggestions Please
: Thanks for the info, John. : : I'll look through some of my old handbooks for ideas. I suspect you're : right: hi fi wasn't what they had in mind for that rig! Why should our AM transmitters of today be considered "hi-fi"? I mean, audio is nice and all, and we're getting a helluva lot more than what can be heard on SSB and if we're only using from 200 to 3.5kHz, we're using plenty more audio spectrum than our SSB counterparts. but, running a rig, with an audio response of 50hZ to 5kHz? Where does the "excessive" line stop? 73 = Best Regards, -=Jeff/W5OMR=-
Re: [AMRadio] Thordarson 6699/Heaven help the neighbors
While folks is looking for transformers, I could use a 5 volt transformer for a pair of 872's. What are they, 7.5amps each? 15amps total needed. 73 = Best Regards, -=Jeff/W5OMR=- Subject: Re: [AMRadio] Thordarson 6699/Heaven help the neighbors : ok John - I'll look, once in a while one gets lucky. Good luck and thanks : again., Scott
Re: [AMRadio] AM operating in Central FL
: : I seriously doubt he'd get you in Wyoming anyway! : : People move there to get AWAY from population centers, and 40m is short skip : daytime band. It's also a place to work JA's and VK's and other DX places at night. Instead of fussing about working 40m during the day - why not go populate some of the more popular daytime, long distance bands, like 20, 17, 15 or 12m? 14.286 Make a place on 17 - is there anything that specifically says we CAN'T operate on 17m? 21.400Mc on 15m. Where on 12m? I more like the 15m idea... I hardly hear -anything- above 21.350Mc anyway. 73 = Best Regards, -=Jeff/W5OMR=-
Re: [AMRadio] Bandwidth
Very true. I had tried to post the information, a week ago, but I used the wrong e-mail address to do it with, and consequently it came back to me, like an Australian boomerang :-) I can not go into detail on my source, but it has in the past been quite reliable. 73 = Best Regards, -=Jeff/W5OMR=- == : Thanks Mike I think your words are spoken with wisdom and fairness! : Let's get more information before we get too heated on this one... : > Gentlemen: : > : > Before lambasting Bob and Riley, should we not verify the story? I sent : some : > email to Bob asking him if what was being passed around is true. He flatly : > denied it and was dismayed when he saw it. There is no plan to limit BW. : > There is, however, some concern on Riley's part about the 7 to 8 kHz SSB : > signals being heard on the bands these days. That is ALL I will say about : > that. : > : > 73 all, : > Mike : > WA5CMI
[AMRadio] Bandwidth
I got this out of discussion not too long ago (few weeks...) == Another thought occurred. wow! While visiting with Bob Heil (the microphone guy) he mentioned that Riley Hollingsworth is working on a bandwidth plan for ham radio signals. The idea is to limit the entire signal to 3kc. They (Bob and Riley) want to limit those individuals who mis-use audio shapers and compressors. This would also allow more people on the band at one time. I know it would hurt the AM signal. Maybe you could come up with a method to limit the size of the AM signal. This is mentioned to be 1-2 years away, but still on the plate. == who can confirm/deny this? 73 = Best Regards, -=Jeff/W5OMR=- --- 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.---
