[Heath] Dead SB-101 IF?

[Alexander N. Gerli]

Hi, gang,

I have a working LMO, rx audio stages and the LSB and USB oscillators are
working (LSB and USB settings sound correct), SSB and CW Filters seem
correct, RF and AF Gain controls work and the S-Meter Zero control zeroes
correctly.

Now...the Preselector doesn't work. no change in tuning sensitivity
regardless of band. I CAN hear a signal. At the top of the LMO, like 490
out of 500, I hear a type of beacon signal fairly weak from WLO, a
commercial mobile Marine Radio voice/data station located in Mobile AL.
AND, the signal is there regardless of the chosen band (so just the LMO is
being amplified, right?). The frequencies they operate on are not anywhere
near the LMO range of 5-5.5MHz.

Somehow the IF and mixers are not working. Tubes check out OK. Wiring
appears clean and original, and someone added a RP Electronics Speech
Processor at some time. But that's in the TX audio line and I'm not going
to deal with that until I get the RX working.

ICOD in my SB-102 Manual has no suggestions if the "Preselector does not
work on Receive" symptom. Can someone on the List help me with some
places/board areas to check?

​73,​


​Sandy AC1Y​


Alexander N. Gerli, Sr.
548 Allred Mill Road
Mount Airy, NC 27030-2202

Scotsmen walk about 900 miles each year.
A Scotsman drinks around 45 gallons of Whisky a year.
Scotsmen get about 20 Miles Per Gallon.
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