[Elecraft] Unusual Behavior K3S / KPA500 Drive Power Greater Than 12 watts

[Rick Bates, NK7I]

Except that it only happens in SSB, it sounds suspiciously like the high 
power amp (final) has failed in your K3S.  But start with your audio.  
Are the settings normal (comp, mic gain etc)?

Can you try another microphone and turn on the monitor function to hear 
what your mic is producing?  Is the two-tone function accidentally on?

What power output can you read when not using the amp and going above 12 
watts?  If more than 12 watts, a calibrate output would be in order for 
for your confidence.

Is it confined to one band?

If you don't get direction of the cause from these tests, a phone call 
to Elecraft service is in order.

73,
Rick NK7I


On 3/3/2020 10:48 PM, Tony wrote:
> All:
>
> I've noticed an unusual thing happen with my K3S and KPA500 amplifier 
> while in SSB mode. When I increase the K3S drive beyond 12 watts, the 
> KPA500 power drops-off dramatically. This only happens in SSB mode.
>
> The KPA500 functions fine with other transceivers as well so the 
> condition appears to be unique to the K3S. Any suggestions?
>
> Tony
>
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