[Elecraft] KPA500 thermal clicks

[Bob McGraw K4TAX]

Yep, mine sounds about the same.   And I too run the fan on #2 when 
working FT-8.  Otherwise, I set it to normal and it cycles on and off as 
needed.  The clicks and pops are considered "normal" as per the KPA-500 
manual and also a friend that was instrumental in me making my 
purchase.    Fact of the matter, the static crashes are louder than the 
amp clicks.

I have acoustic material on the wall behind the amp.  That absorbs a lot 
of sound that would normally be reflected into the room, both from the 
fan and from the clicks.

73

Bob, K4TAX



On 7/18/2018 6:45 PM, Michael Blake via Elecraft wrote:
> Andy, mine sounds very much like your recording.  When on FT8 and using the KPA500 I usually set its fan to 2 and it seldom ramps up past that speed.
>
> Your recording sounds very normal to me.  Maybe not a good thing but normal :)
>
> 73 - Mike - K9JRI
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>> On Jul 18, 2018, at 7:25 PM, ANDY DURBIN <a.durbin at msn.com> wrote:
>>
>>
>> I placed my Android phone on top of my KPA500 and made a recording while making a few cycles of FT8 TX/RX.  The audio files can be found here:
>>
>> https://www.dropbox.com/sh/amfy3dz8pgl083n/AAAKi2GYripXyIDjiLpJ2hDwa?dl=0
>>
>>
>> One file is the raw recording.  The second has been processed in Audacity to amplify to 0 dB peak.  The file starts before the first TX. Next the hum of the transformer can be heard with FT8 modulation in the background from TX moni.   As the recording progresses the changes in fan speed can be heard.   The click are always well above the fan noise.
>>
>> I used this recording to perform some spectral analysis of the clicks.  I took one sample at the click and another sample of the noise just before the click.  I then subtracted the noise from the click and I think I have a reasonable click signature to use as a baseline for evaluating any mechanical changes I make in an attempt to reduce the clicks.
>>
>> Crank it up and enjoy, especially if you think it's normal.
>>
>> 73,
>> Andy k3wyc
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