Phil Clements wrote:
>
> Your amp is doing better than factory specs on all bands, Vic.
> Read the specs again....750 watts SSB and 500 watts DC.
I presumed this referred to duty-cycle considerations. In other words, 500
watts RTTY. Anyway, if the amp can't deliver 750 watts CW for a short period,
then it is saturating at not able to deliver 750 watts peak in CW either.
> I did find a problem in my amp in the 10 meter low pass filter. A cap
> had changed value (or never was in tolerance) and moved the 10 meter
> cut-off frequency up into the 10 meter band. The output will never be a
> much on the higher bands, as an attenuator is switched in @ 20 meters
> and above to cut the drive considerably.
Henry said that the small increase in output that I see when increasing drive
past 100 watts indicates that the amp is saturating (I'm not sure exactly what
this means) and that reducing the attenuation wouldn't help. It would be easy
to change the attenuator, but I'm afraid of damaging something by increasing the
drive further.
> If you ever see a lower output on a particular band, sweep the output
> filter for its cut-off freq. It may have moved. The disk caps are a little
> small IMO.
I think I will feed a few watts from my calibrated signal generator (otherwise
known as a TS850s) through the filter to a dummy load. I'll put my scope across
the dummy load and see if I can determine anything. That will be a fun
experiment, and I'll report the results.
73,
Vic, K2VCO
Fresno CA
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