[Elecraft] KPA500 finals blown

[Jim Miller]

I've run echo tests on 6m EME for hours at a time which is 50% duty cycle
and 500w+.

I always run RTTY contests at 500+.

Yes the fans get going. That's what they're supposed to do. But I've never
had a problem.

73

jim ab3cv



On Thu, Jan 21, 2016 at 1:12 PM, Fred Jensen <k6dgw at foothill.net> wrote:

> Well ... it says that, in any 15 minute interval, you can be key-down
> continuously for 10 minutes followed by key-up for 5 minutes which looks
> like a 0.66 duty cycle on my slide rule.  Presumably, this could be
> followed by another such sequence.
>
> Is 10 min down/5 min up repeatedly the same as 40 sec down/20 sec up
> repeatedly?  Intuitively, it seems to me that the PA-heatsink will come to
> some equilibrium temp and a 10m D/5m U duty cycle may not yield the same
> final temp as a 60s D/20s U duty cycle.  Then again, I struggled through
> Thermodynamics.
>
> I know the original KPA500 field testers were encouraged to run the amp at
> "full bars."
>
> 73,
>
> Fred K6DGW
> - Northern California Contest Club
> - CU in the Cal QSO Party 1-2 Oct 2016
> - www.cqp.org
>
> On 1/21/2016 7:53 AM, Phil Wheeler wrote:
>
>> This in the specs in the KPA500 manual "Duty Cycle at 500 Watts 10
>> minutes key down / 5 minutes standby" seems pretty definitive for normal
>> operations, even RTTY, Earl.
>>
>> 73, Phil W7OX
>>
>
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