Yep, I think it was a 6-month suspension, not a year as I stated earlier. (I plead slightly flakey memory.)
Bacon, WA3WDR ----- Original Message ----- From: "Donald Chester" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Saturday, February 18, 2006 8:45 PM Subject: RE: [AMRadio] AM Transmitter Advice?? > John, WA5BXO wrote: > > >As I understand it the trick, that the FCC was to prevent, and someone was > >trying to get away with, was to run a 304TL with about 100 Volts on the > >plate in a GG configuration. Forward bias it to a high plate current like > >1 > >Amp, so that it acts like a switch that is on. Then drive it with 5 KW > >PEP. > >It may have been some other some scenario as this but I think you get the > >picture. > > I had never heard of that, but it makes sense that someone might try it. > > > > Then there was the trick that a gentleman up in 3 land, I think, was > >going to run the high level double sideband reduced carrier generator type > >rig but he was not reducing the carrier just increasing the SBs via an > >extra > >upside down tube, as it was commonly called. The sideband power would > >continue to go up without distortion (if copied on a proper synchronized > >product detector) after the first tube was over modulated in the negative > >direction. The voltage and power would be diverted to the upside down tube > >where sideband power would continue. There was trouble with the specific > >rule interpretation at the time in the FCC. Of course any of us today, > >would > >be able to see that the upside down tube's audio plate current and audio > >voltage must also be counted as part of the input power. But the FCC was > >having trouble deciding, at least as I understand it. At any rate, I think > >they got him for being outside the 40 meter band limits. You may remember > >more of the specifics on this Don. > > I knew the gentleman personally. It was Fred, W3PHL, near Phila, PA. I met > him at many hamfests, and visited him one weekend back in about 1971. I saw > his rig, but by that time he had converted it to a big SSB linear. He liked > to ragchew with VK's and ZL's in the pre-dawn hours on 40m, using a 120 ft. > high beam. He not only fought the FCC, but had to deal with a tower case as > well (which he won). > > The loophole in the regulations was that the definition of power was DC > input to the final. With the upside down tube circuit, he ran about 600 > watts DC input, and then applied several kw of audio. The rig was basically > a high-level balanced modulator, but with DC applied to one tube, which > effectively unbalanced the modulation, he claimed it was a plate-modulated > AM rig, and that the legal power measurement was limited to the DC input to > the final. > > The signal was double-sideband reduced carrier, with several kilowatts in > the sidebands and less than 500 watts carrier power. Althhough a > synchronous dectector would have have taken full advantage of both > sidebands, most of the people he worked actually used SSB receivers, and > simply copied either USB or LSB, and used the carrier only as a pilot > carrier for setting the frequency on their receiver. > > The FCC couldn't make up its mind on how to deal with the issue, even > though they could have cited a rule on the books that limited modulation to > 100%, and they could have said he was modulating over 100% in the positive > direction, regardless of the fact that the signal was clean. Instead, they > ended up citing him for splattering outside the 40m band. He liked to > operate at 7290, and even though he had engineering data to prove that his > signal met all FCC specifications regarding spurious sideband products, they > said that the rules allow no detectable signal whatever outside the limits > of the amateur band, and he had detectable sideband products above 7300, > even though they might have been 50-60 dB down. > > I understand this whole thing was part of an ongoing feud between Fred and a > SSB group that was competing for the frequency, and the issue was brought > up when the SSB group complained to the FCC. They suspended Fred's licence > for six months based on the citation for out-of-band distortion products. > > The FCC referenced that case when they railroaded through their p.e.p. power > rule. > > Don K4KYV > > _______________________________________________________ ________ > > This message was typed using the DVORAK keyboard layout. Try it - you'll > like it. > http://www.mwbrooks.com/dvorak/ > http://gigliwood.com/abcd/ > > > _______________________________________________________ _______ > AMRadio mailing list > Home: http://mailman.qth.net/mailman/listinfo/amradio > Help: http://mailman.qth.net/mmfaq.html > Post: mailto:[email protected] > AMfone Website: http://www.amfone.net > AM List Admin: Brian Sherrod/w5ami, Paul Courson/wa3vjb >
