[Elecraft] KPA500 thermal clicks

[Martin Sole]

I think a more realistic measurement than the original, phone on the amp 
cabinet would be to place the phone on something like a tripod roughly 
where the operators head might be. That is likely to be a more balanced 
level.

That said I'm not sure that having the specific absolute level in one 
particular environment is necessarily all that useful, in this case. 
Having a number, defined in specific terms doesn't help me to feel one 
way or the other if that would impact on my operating. But if I can hear 
what Andy hears and it sounds anything like what he recorded then I 
would be looking at ways to mitigate it. Recording and amplifying the 
offending sound as much as necessary in order to identify the root would 
seem a good start.

What Andy showed is that there is a ticking sound and that sound is 
being produced by an action on one or more materials. If they can be 
identified it is possible that sound can be reduced. Whetherit is a loud 
or quiet sound is of less significance, we all hear differently.

Martin, HS0ZED




On 19/07/2018 09:31, Bob McGraw K4TAX wrote:
> All of these "relative" recordings have little to no value in terms of 
> "how loud" the noise may be.   Yes, it is there. Amplify it enough and 
> it will blow the side of the house out.  The phone on top of the amp 
> is certainly not where ones ear may reside.
>
> If one wishes to cite how loud a sound exists, then use a sound level 
> meter and measure the noise at a specific and stated distance and 
> several different axis and report the level in dB. A weighted or C 
> weighted.   Also measure and state the level of the room ambient.    
> Use a spectrum analyzer to quantify the nature or content of the 
> sound, frequency and waveform.   Those numbers will then equate to 
> something that is meaningful.   If others do the same, then there is 
> contained evidence of units which may contribute to the artifact of 
> concern.
>
> 73
>
> Bob, K4TAX
>
>
>
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