Heathkit SB-10 Series Troubleshooting Manual page 33

l) FREQ CONTROL - LOCKED NORMAL.
m) RF GAIN - fully clockwise.
n) FILTER - SSB.
o) METER - ALC.
p) AF GAIN - 9 o'clock position.
p.1. S-Meter Adjustment
After a few minutes warmup, adjust the METER ZERO control (on the IF circuit board
directly behind the FREQ CONTROL switch) for a zero reading on the panel meter.
p.2. Receiver Alignment
Set the VTVM switches so the meter will indicate a negative (-) DC voltage.
Connect the common lead of the VTVM to the chassis and the other lead to the circuit
board foil at TP on the screened side of the bandpass circuit board near tube V19.
The heterodyne oscillator output will be checked at each position of the BAND switch in
the following steps.
a preliminary output voltage reading. Final adjustment will be made later.
p.2.1. Preliminary Heterodyne Oscillator Alignment
With the BAND switch· at 3.5, the VTVM should indicate about -0.5 to -2 volts DC. If
necessary, adjust coil 3.5 (near tube V11 on the top side of the RF -driver circuit board)
for the proper VTVM reading. NOTE: When adjusting this coil in one direction, the
oscillator output voltage will change rapidly; when adjusting the coil in the opposite
direction from the peak, the output voltage will change slowly. Adjust the coil in the
direction that gives the slower change in output voltage.
Similarly, check the heterodyne oscillator output voltage at all positions of the BAND
switch. necessary, adjust the correct heterodyne oscillator coil for any BAND
If
switch position that does not give an indication of about -0.5 to -2 volts DC on the
VTVM. The heterodyne oscillator coils for bands 3.5, 14, and 28.5 are marked, and
adjusted at the top side of the RF –driver circuit board; the coils for the other bands are
marked on the shield cover, and are adjusted from the bottom of the chassis:
Note: If adjusting from the bottom side of the chassis, the 3.5 MHz core is also the
core on the 7 MHz coil that is closest to the chassis, the 14 MHz core is also the
core on the 21 Mhz coil that is closest to the chassis and the 28.5 MHz core is also
the core that is closest to the chassis on the 29.0 MHz coil.
Alignment
necessary, the heterodyne oscillator coils will be adjusted to obtain
If
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