Can anyone point me at a design for a linear amplifier
suitable for running data modes such as PSK08 or WOLF?
Not many seem to be doing this any longer, but an audio power amplifier is a
possibility. I'm using an unmodified Hafler P3000 amp at the 200 watt level.
Picked it up from eBay at considerably less than the new price. I confess to
not having made any linearity measurements, though, and it's possible that
the thing is less than perfect.
I haven't gone beyond 100 watts in the continuous key-down modes, partly out
of respect for the present output transformer and low pass filter. All of
the bits are here for heftier versions of both, and they should be ready for
the next season. I do have two small fans blowing air through the amp's heat
sinks, and that makes a big difference.
John Andrews, W1TAG/WD2XES