Drake R-4B Issues; Part V
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This has been a great learning process and a lot of fun.
What I now believe the issue of crazy S-Meter readings is due to the
frequency of the Second LO Crystal (5,595 KHz) being off frequency.
In the Alignment Procedure (para. 6.4.5) it calls for zero beating with
C61. In my case, C61 (1-8 pf) had little or no effect. I added 24 pf cap
across C61 and saw a dramatic decrease in tone frequency. I changed
out the 24 pf for a 50 pf and saw the tone frequency drop further.
I also saw a corresponding increase in S-Meter reading. So my guess is,
the Crystal being off-frequency shifts the resultant signal in the passband
enough to cause the S-Meter to read wrong.
However, there's just so much C you can add before the Oscillator stops.
So, what I need to find is an organ donor R-4 and either just get the
Crystal, or get the whole board.
Any donors out there ??
73, Dick, W1KSZ
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Dick