How do you figure that? _______________________________________________ Amps mailing list Amps@contesting.com http://lists.contesting.com/mailman/listinfo/amps
That's true with AM as no-modulation carrier power became reduced but I believe most other modes, including SSB and CW benefited from the FCC's rule change. Paul, W9AC ______________________________
There was no limit on the peak envelope power we were allowed to run; only a limit on the average power as read on the plate meters. Peak envelope power can range from 5 to 10 times or greater than
AM'ers lost some ground when cut back to 375W carrier for a 100% plate modulated rig. No other modes should be complaining. 73, John WA4TT _______________________________________________ Amps mailing
Tom, I believe AM was the only mode adversely affected by FCC Docket 82-624. A 100% sine-modulated carrier of 375 watts output produces ~ 1500W PEP out. But under the old rules of a maximum limit of
Also, I always claimed 70% or better for my class C finals-- but had no way of really knowing. Didn't own a watt meter til the late 70's. :>) ................/ TT ____________________________________
Wasn't there also an FCC rule that the time constant of the meter should not be greater than 0.25 seconds? How an FCC field engineer could have checked that was left to the reader's imagination. -- 7
OK, I see your point. Good point Gary and one that almost everyone misses. Conventional thought is the peak to average power ratio is only about 2:1. While that may be true for processed speech (eve
For unprocessed speech, the CCIR long ago established an 8 dB peak/average ratio. This may be on the low side, as I have seen 9 and even 10 dB ratios in literature about FDM carrier system loading. U
I believe that Bell Labs many years ago published that the ratio of average to peak speech power was 15 or 16 db. As to the .25 second meter time constant I remember reading somewhere that it was acc
Hi Tom, Back then most people did believe that PEP was 2x the average power which was true for a two tone test but not with voice. Even then most manufacturers published specs on amplifiers and radi
Gary, Most of the amplifiers of that day did not have the power supply and/or tube capacity to supply even a 6 dB peak to average ratio. In many cases the amplifier was doing the "speech processing"
Also I think most people believed that with 1 kw average Correct me if I am wrong, but didn't the ARRL license manual back in the early 60's early 70's perhaps say that PEP was about 2 times DC plate
About peak versus average or DC: I am fairly sure that such a statement WAS made - but it was for two-tone testing, where you had a pair of sinusoids added to form the modulating signal, continuously
The ARRL ssb handbook used to say something like that. They did say with 2 tone test but also alluded to the 2 times average for voice also. I Not sure what you are saying here? Are we getting over
That is for UNPROCESSED speech (that is, no compression, peak limiting, AGC, or peak clipping, and little or no EQ). Dynamics processing and EQ can easily reduce that ratio to 3-6 dB. Stick a modulat
Author: Peter Chadwick <g3rzp@g3rzp.wanadoo.co.uk>
Date: Mon, 16 Oct 2006 10:01:08 +0200 (CEST)
the peak output to be linear ... < Not necessarily, if it has the right metering. Provided the metering can look at the relative phase and amplitude of anode and input volts, the amp can be tuned cor
Correct. [ snip ] That is peak - I mean peak instantaneous as in 50 microsecond charge time for the timing capacitor. This is a whole nuther number when compared to average or RMS. Lengthen that cha