[Elecraft] K2/100 birdie at 28.020 MHz

[jeff martin]

Bruce, Geoff and Don,
Sorry I am late in replying and thanking all for their help. The little power plant I work at here in South Texas has been demanding my attention with the cold weather here! They didn't build these plants with this kind of cold in mind!

I will give the ideas a try this weekend, and let you all know how it worked out. 

73,
Jeff N7KRT
--- On Wed, 2/2/11, Don Wilhelm <w3fpr at embarqmail.com> wrote:

> From: Don Wilhelm <w3fpr at embarqmail.com>
> Subject: Re: [Elecraft] K2/100 birdie at 28.020 MHz
> To: "jeff martin" <n7krt_1 at yahoo.com>
> Cc: "Elecraft Discussion List" <elecraft at mailman.qth.net>
> Date: Wednesday, February 2, 2011, 7:54 AM
>   It may also be helpful to tuck
> the ribbon cable and speaker wire up 
> into the space above the control board.  Remove the
> right side panel and 
> tuck the wires in front of the heat sink.
> It may not help with this particular problem, but it will
> help with 
> other "noises and funny sounds" on SSB.
> 
> 73,
> Don W3FPR
> 
> On 2/2/2011 9:46 AM, Geoffrey Mackenzie-Kennedy wrote:
> > Jeff,
> >
> > I see that Bruce K1FFX has made you aware of Don's
> (W3FPR) and my comment on
> > the "birdie" that Bruce found on 21029 kHz, which also
> disappears when the
> > KPA100 is not active. However may I add a little
> more.
> >
> > Don speculated that some of the oscillator energy (HV
> Bias oscillator) could
> > be picked up by the T/R switch when the KPA100 is
> in-line, and I can confirm
> > that this is fact. The fundamental and harmonics
> generated by this
> > oscillator and the assocated voltage multipliers are
> also found in many
> > other places in the KPA100.
> >
> > It might be worthwhile to remove the audio leads from
> the KPA100 board, i.e.
> > those which connect to the K2 and to the speaker, to
> see if in your case
> > this affects this particular "birdie". The bundle of
> pcb traces in this area
> > (and other areas) of my KPA100 was quite hot with RF
> from the HV bias
> > oscillator/ voltage multiplier.
> >
> > 73,
> >
> > Geoff
> > GM4ESD
> >
> >
> > Jeff Martin N7KRT wrote on Wednesday, February 02,
> 2011, at 12:26 AM:
> >
> >
> >> I have a loud birdie at 28.020 MHz on my K2/100.
> The KPA100 is integral to
> >> the K2. I thought it might be from the 4.0MHz
> oscillator on the KPA100, but
> >> the birdie does not respond to changes of C27. The
> birdie stops when the
> >> power is reduced to low power mode. The birdie is
> loud...can be heard when
> >> the 2nd antenna is selected with no antenna
> connected.
> >>
> >> This may have been covered before, but I seem to
> recall that there was no
> >> firm resolution? I never reaaly worried about it
> for the past few years,
> >> but with the solar cycle waxing, I might miss some
> DX!
> >>
> >> Thanks all for any insight.
> >>
> >> Jeff Martin
> >> N7KRT
> >> K2/100 #5471
> >
> >
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