Hi All,
Class C, D, and E amplifiers are not that hard to modulate. Rather than do
anything so drastic as tinkering with PWM in the RF driver stages, apply PWM
methods to the power supply for the final!
Yes! I have tried this with PSK31 (at QRP level) and it works very well.
I got my inspiration from Clint Turner and his beacon:
http://www.ussc.com/~turner/psk_transmitter.html
At higher power levels, more attention must be paid to reduction of
sidebands from the finite resolution of the PWM and of course the
PWM frequency itself.
Good luck with your 340V PWM modulator Andy! Perhaps the
explosions can be heard here in Sweden? ;-)
73
Johan SM6LKM
|
