[Elecraft] KPA500 finals blown

[Michael Cozzi]

     Irwin,

     There's an easy modification you could do that might net 4-5c 
reduction in temperature.

     On the top of the amp install an additional matching fan blowing 
*in* through the intake. One could conceivably wire it to the fan power 
on the amp (though I would check what max draw is for that circuit). 
This will increase the air velocity, turbulence, and the CFM of the 
entire cooling chain.

     Learned this little trick working with computer water cooling. Was 
trying to keep a 220w TDP processor below 50c under load. If you can't 
get more surface area on a heat sink or radiator- increasing CFM and air 
turbulence can make a big difference.

     Michael KD8TUT

On 1/21/2016 11:26 AM, Irwin Darack wrote:
> In discussions with Elecraft at Dayton, we should be able to run the KPA500
> at 300 watts during a RTTY contest. This would include Running versus S/P.
> The fans on mine do come on high and I keep an eye on the temp reading. I
> do need to stop occasionally to allow the amp to cool down. I am not sure
> if there is a way to add an addition external fan to increase the air flow?
>
> Irwin KD3TB
>
> On Thursday, January 21, 2016, Phil Wheeler <w7ox at socal.rr.com> 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
>>
>> On 1/21/16 6:44 AM, efortner wrote:
>>
>>> I would like to know what the continous keydown power output rating is.
>>> The
>>> manual talks about ICAS. I know when I get on RTTY I does not take long
>>> for
>>> The fans to come up to full speed running 300 watts.
>>>
>>> Earl, K4Kay
>>>
>>> -----Original Message-----
>>> From: Elecraft [mailto:elecraft-bounces at mailman.qth.net] On Behalf Of
>>> Nand
>>> Kishore
>>> Sent: Thursday, January 21, 2016 4:29 AM
>>> To: elecraft
>>> Subject: [Elecraft] KPA500 finals blown
>>>
>>> KPA500 shut off with a bang while operating RTTY @300W.
>>>
>>> Antenna is a steppir beam.
>>>
>>> On opening the KPA500,found 2 ceramic? caps of VRF2933
>>> adrift with underside of the said caps,black.
>>>
>>> Have written to support.Is this the first time this has happened
>>> in a KPA500?
>>>
>>> 73 and HNY,
>>> Nandu
>>> VU2NKS
>>>
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>