[Elecraft] KPA500 finals blown

[Eric Swartz - WA6HHQ, Elecraft]

The KPA500 will automatically go into standby if it feels it is getting too hot. 
This is done with a safety margin between that temperature and the max operating 
temp for the PA's.

Its perfectly OK to operate it at the full fan speed. We expect it to go there 
in normal higher duty cycle operation.

73,

Eric
/elecraft.com/

On 1/21/2016 10:20 AM, Jim Miller wrote:
> 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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