SB-401 CW Chirp problem

[Darwin D. Geiselbrecht]

I know this sounds a bit far fetched. But in my case, I traced this problem
to the fact that the het osc is not fed from a source of regulated voltage.
As I remember,  the stock SB-301 lacks Bplus regulation of any kind.  In my
case, the source of power to the station (years ago) was kind of soft such
that the RX Bplus dropped when the TX was keyed.  I installed a OA2 regulator
on a small metal bracket under the chassis to clear the problem.  However, if
the cause is similiar, you might try a simpler approach by ensuring that the
source of power to the rx and tx are as separate as possible (i.e. for sure
don't feed them from a common power strip).  Just a hint from my experience,
your mileage may vary.

Good luck 73 - Darwin K5DOA

PS - the equivalent het osc in the 401 has a regulator. Hence no issue when
operating standalone.

In a message dated 12/29/02 18:08:06 PM Central Standard Time,
mvjohn at SYMPATICO.CA writes:

<< Wondering if anyone has had problems with "Chirp" reports using  an
 SB-401/SB-301 combo. I've gotten them  (chirp reports) on 20 and 15
 meters lately and I have it narrowed down to the  Het Osc in the SB-301.

 When I listen to my signal  on another receiver while transmitting into
 a dummy load, I can hear the frequency shift enough to be "chirpy". When
 I transmit using only the SB-401 in stand alone (I have the optional
 Xtal pac) the chirp goes away. >>

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