Pierre,
When something changes like that, my first suspicion is that there is a poor
solder connection somewhere in the BFO area. I suggest reflowing the solder
connections a both crystals (sorry, but you have to lift L33 to get at the
crystal pins), then the varactors (D37 and D38) also the connections for the
voltage to the varactors (RP6 and the connections back to the Control Board
for the V BFO signal (Ctrl Bd U10 pin 14 is the origin and P2 pin 31 is the
connector - also the RF board connector J7 pin 31).
If that does not resolve the range problem, check the voltage on the V BFO
signal while checking the range in CAL FCTR mode (check at Control Board U10
pin 14) - the voltage should be near 8 volts for one end of the range check
and near zero volts at the other end of the range.
73,
Don W3FPR
> -----Original Message-----
> I recently built K2/100 # 5170. At the BFO Test (page 62), using
> CAL FCTR, I got correct readings: Center at 4913,55 kHz, BFO High
> 4917,23 and BFO low at 4912,41 respectively.
>
> But something new is happening. The readings changed to 4913,85
> (C), 4915.97 (H) and 4913,58 (L).. so that the narrow filters (<1
> kHz) are almost impossible to center correctly. I use the
> Spectrogam method to adjust the filters.
>
> Where should I look to get it back to the previous range?
>
> Thanks de Pierre VE2PID
>
>
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