[Elecraft] K3 powers off when after several minutes of 12W carrier

[Wes Stewart]

Doubt that.  From what I've gathered during a lot of TX IMD testing on my 
original K3 and my K3S, with several (lost count) different LPA and HPA modules, 
it's a 10W amp.  It's allowed to go to 12W but that's a really, really bad idea, 
from an IMD standpoint.  IIRC it's been asked that this be "fixed" in firmware 
but it hasn't seemed to be put "on the list."

Wes  N7WS

  On 3/29/2018 4:50 AM, hawley, charles j jr wrote:
> How do we know that’s pushing it? Maybe the LPA is designed for 20 Watts and the K3 cuts them off at 12 Watts.
>
> Chuck Jack
> KE9UW
>
> Sent from my iPhone, cjack
>
>> On Mar 28, 2018, at 7:23 PM, "john at kk9a.com" <john at kk9a.com> wrote:
>>
>> Instead of pushing the 12 watt PA this hard it would sure be nice (and
>> cleaner) to have the option of using the KPA3A for 10-12 watts output.
>>
>> John KK9A
>>
>>
>> K7TV wrote:
>>
>> I have been testing sustained power capabilities of wideband HF transformers
>> for feeding EFHW antennas. This involves running high power through HF
>> transformers back to back into a dummy load. When running 200W out of the
>> KPA500, the K3 was indicating 12W, and I think that means the 100W PA was
>> not operating. After a few minutes the K3 totally shut down. This had
>> nothing to do with the transformers under test; I get the same result when
>> running the KPA500 at 200W directly into the dummy load. After restart the
>> K3 shows no sign of problem unless the 200W endurance test is run again.
>> Then I increased power just a little bit so that the 100W stage kicked in. I
>> got 300W out of the KPA500, and now the K3 keeps going without shutting
>> down. I can see how 12W may be a bit much for the driver stage, but if so,
>> shouldn't the 100W stage kick in sooner? Also, I expected the K3/KPA500
>> combo to be able to produce any power level I wanted within its range. What
>> I see is that when the 100W stage kicks in, the output (as seen on an analog
>> meter) makes a big jump so that certain power levels cannot be achieved.
>>
>> Thanks,
>> Erik K7TV
>>