[TowerTalk] SWR question

[GEORGE PRITCHARD]

I would actually  PREFER TO MEASURE THE INPUT DC POWER since I prefer operate a vintage home brew "1KW input" Class C AM transmitter. If I get 75% efficiency, I get 750 watts forward power. On positive modulation peaks (X4 since the voltage is doubled) I would read 750 X 4 or 3000 watts peak. This was the way it was before the 1500 watt rule change, so now the AM transmitter must be -3dB foward power since the old days. On the other hand, the SSB operators use to be under the 2KW input rule, giving an output power of about 1KW for a typical lower efficiency linear amplifier at about 50%. With the forward power permitted now at 1500 watts... a SSB operator gets an increase in power of +3dB from the old rules.  If we want to be "qute", we could put the power sensor at the antenna feed to give ourselved the loss of the feedline, maybe 1dB? not much to worry about. Whats 1to 3 dB among friends anyway?
Georgwe AB2KC   1KW AM