[Boatanchors] 813 grid to filament short

[Rob Atkinson]

Forgot to mention another reason why this notion of precision
measurement of power is ludicrous--who delivers transmitter power into
a 50J0 load when operating.

Run your rig, whatever carrier it puts out--fully modulate it and
forget it.  Leave the illusion of "375 watts" power nonsense to phony
operators who think they can measure it.  I usually tell folks I run
300 watts give or take 25 to 50.  That's into a Bird dummy load with a
thermocouple RF amp meter and Bird 43 and I interpolate.

73
Rob
K5UJ

On Thu, Oct 1, 2015 at 11:09 AM, Michael Clarson <wv2zow at gmail.com> wrote:
> On the PEP issue, here is a brain exercise. I know there is a mathematical
> basis for PEP, and, that mathematically, 375 watts AM is 1500 watts PEP. So,
> lets assume (to simplify the math) that our transmitters are 100% efficient.
> On CW, if we output 1500 watts, PEP is 1500 watts, and our 100% efficient
> amplifier draws 1500 watts from the power supply. Makes sense. Now, if we go
> to AM, and we put out 375 watts 100 % modulated, the RF puts out 375 watts,
> and the modulator adds 187.5 watts. Total draw from the power supply is
> 562.5 watts, yet produces 1500 watts PEP. The 1500 W PEP on CW requires 1500
> watt dissipation in a dummy load, yet the AM 1500 watt PEP only requires a
> 562.5 watt load. Perhaps a single PEP value is not he best way to specify
> transmitter power. --73, Mike, WV2ZOW
>