[Elecraft] K3: KPA100 Squeal

[Guy Olinger K2AV]

A repeated 12 kHz would be echoed all over the room and lose a lot of
it's pulse nature.  This continues to look suspiciously like crap from
a 12 volt switching power supply that is somehow finding something
mechanically resonant in the K3.

Back to asking for 12 volts from a linear supply (transformer and 60
Hz rectifiers) or battery.

Is this particular K3 serial # prior to the introduction of gold
plated pins for the KPAIO3 connection?

73, Guy.

On Thu, Jun 30, 2011 at 1:52 PM, W5UXH <Chuck.Broadwell at gmail.com> wrote:
> I looked at the MP3 file using Goldwave.  It appears to me that the "12 KHz"
> component is present only during the tics, not continuously.
>
> The tic period is roughly 270 msec (I have no idea what the tic is of
> course).   I zoomed in to a single tic (see PDF of images at the link
> below).  It appears that each tic has a very distinct pattern seen in the
> individual samples which I suspect is the 12 KHz energy.
>
> I have no idea what any of this means.
>
> 73,
>
> Chuck, W5UXH
> Las Cruces, NM
>
> https://sites.google.com/site/k3lineoutrecordings/ab3ls-mp3-file-analysis
> Images and comments from Goldwave view of the MP3 file
>
>
> Guy, K2AV wrote:
>>
>> Hi Geoff, below...
>>
>> On Thu, Jun 30, 2011 at 9:24 AM, Geoff Wolf AB3LS
>> &lt;liltechdude13 at gmail.com&gt; wrote:
>>> And, for even more information, I analyzed the audio that I recorded and
>>> the
>>> squeal is right around 12Khz. It peaks at -48dB (louder than the QSK
>>> relay
>>> clicking)
>>>
>>> http://imgur.com/V8o5t - image of the analysis
>>>
>>> AB3LS
>>
>> With your image I realize I had been making some assumptions.  I need
>> to fill in some details...
>>
>> Are you listening to the audio in earphones or are you hearing it in
>> the free air.  I had been assuming listening with your ears only in
>> free air to miscellaneous sound in the neighborhood of the K3.
>>
>
>
> --
> View this message in context: http://elecraft.365791.n2.nabble.com/K3-KPA100-Squeal-tp6518460p6534295.html
> Sent from the Elecraft mailing list archive at Nabble.com.
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