K2 Drifts in Transmit

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K2 Drifts in Transmit

WB3AAL
Hello,

 Wondering if anyone has the same issue with their K2.

K2 is a QRP radio SN 01392.

 This happened to me two times today. Occasionally when I come down into the
shack and turn on the K2 I will tune around for a few minutes looking for
anyone calling CQ. When I hear a station I will send my call sign. When I go
to give the usual RST, name and QTH the VFO will drift up. The weird thing
is that I can clear the problem by turning off the radio, wait 10 seconds,
and then turn it back on. The VFO is stable and will not drift while I
transmit.

Today when I saw the rig drifting again I placed the rig on the dummy load.
It will continue to drift until I turn it off and wait 10 seconds then turn
it back on. Like I said it does not happen all the time.

73
Ron Polityka
WB3AAL


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Re: K2 Drifts in Transmit

Don Wilhelm-4
Ron,

Does the displayed frequency change?
Is there some drag on the VFO tuning knob?  If the knob is
"free-wheeling", it can drift from its position easily.

It may be that a solder connection in the PLL Reference Oscillator, or
the BFO or the VFO has developed some oxidation over the years.
Reflow the soldering in those areas.  To identify the components, look
at the RF Board schematic sheet 1 - everything on the top of that sheet
has to do with the PLL and VFO.  The BFO is on the lower right corner of
sheet 2.

73,
Don W3FPR

On 11/7/2015 6:17 AM, WB3AAL wrote:

>   This happened to me two times today. Occasionally when I come down into the
> shack and turn on the K2 I will tune around for a few minutes looking for
> anyone calling CQ. When I hear a station I will send my call sign. When I go
> to give the usual RST, name and QTH the VFO will drift up. The weird thing
> is that I can clear the problem by turning off the radio, wait 10 seconds,
> and then turn it back on. The VFO is stable and will not drift while I
> transmit.
>
> Today when I saw the rig drifting again I placed the rig on the dummy load.
> It will continue to drift until I turn it off and wait 10 seconds then turn
> it back on. Like I said it does not happen all the time.
>

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