[Elecraft] K3: KPA100 Squeal
Geoff Wolf AB3LS
liltechdude13 at gmail.com
Fri Jul 1 01:24:25 EDT 2011
This is a brand new K3 that I assembled about a month ago. The Serial Number
is 5517.
I have been using an Astron SS-25A power supply with this which is indeed a
switcher. I have a battery that I'll be hooking up to it to see if this is
still a problem.
On Thu, Jun 30, 2011 at 4:41 PM, Guy Olinger K2AV <olinger at bellsouth.net>wrote:
> 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
> >> <liltechdude13 at gmail.com> 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.
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:Elecraft at mailman.qth.net
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> >
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:Elecraft at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
More information about the Elecraft
mailing list