My memory is getting old, and it was always a little flakey, but I really seem to remember that there was, at least at one time, an FCC spec on the time constant of the plate meters in amateur transmitters.
I did a search, but all I could find was this hint: http://www.dproducts.be/Drake_Museum/l-4b.htm Drake L-4B Linear Amplifier "Plate Current Meter time constant is consistent wit Bacon, WA3WDR ----- Original Message ----- From: "Jim Wilhite" <[EMAIL PROTECTED]> To: "Discussion of AM Radio" <[email protected]> Sent: Saturday, February 18, 2006 7:28 PM Subject: Re: [AMRadio] AM Transmitter Advice?? > Bacon, not trying to be contrite, but where in the old rules did the .25 > second time constant appear? I have a copy of the old rules and don't see > it. It says only that "have the means". > > 73 Jim > W5JO > > > At that time, plate power input to an AM > > transmitter was measured by the reaings of DC meters > > with approximately 0.25 second time constant. That > > time constant would make the meters read average > > voltage and current, which smoothed out SSB and > > controlled carrier signals. But on plate-modulated AM > > it did not read true power during modulation, because > > it was looking at average voltage and average current > > separately, while in AM the voltage and current are not > > separate, but they increase and decrease together, > > resulting in higher power input during modulation. > > > _______________________________________________________ _______ > 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 >
