Drifting SB-301

[Fred Wittman]

Janusz Juryk wrote:

>Greetings everyone,
>
>I have recently started having problems with my SB-301
>receiver. The 301/401 combo is setup in the transceive
>mode using the receivers LMO.  Couple weeks ago
>towards the end of a lengthy QSO, the receiver started
>drifting 4-5 khz up and down and I was not able to
>bring it back to the frequency that I was operating
>on. A few days later I fired up the receiver and let
>it warm up for a good 30 minutes and surfed the bands
>and had the same problem and also had a lot of  say
>chirping birds as I moved the main dial.
>
>Could anyone help me out in rectifying this situation?
>
>I love my Heathkits and have a blast operating them.
>
>Cheers
>
>Janusz   ve2zhp 
>
>
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Janusz,

First thing that comes to mind is that, due to the age of these rigs, 
corrosion sometimes creeps into ground connections, particularly in 
VFO's.  The "birdies" may indicate a grounding problem in your IF 
circuitry.  A good place to start would be to retighten every screw/nut 
combo that attaches the board to the case, possibly even remove the 
board and clean the case contact points.  Also, when you operate the 
VFO, try pushing against the case or pressing against the knob to see if 
you can repeat the drift.  I'm suggesting this because I'm reserecting 
an old HW-101 with a similar problem.  Hope this helps.  73's.

Fred - KG6NYK

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Products bought, sold or traded here is the responsibility of the
parties involved.  This list and the City of Tempe are not responsible
for losses or misrepresentations of any kind.  Buyer beware!

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This list is a public service of the City of Tempe, Arizona
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