Figure 10-5. Wattmeter Interconnections.
Section III. OPERATION
g. Slowly adjust the VOX BAL control until the
10-6. Phone Patch Operation of Collins
relays stop tripping.
312B 4/5 With Collins KWM-2/2A
h. Repeat f and g above, until it is no longer
possible to advance the VOX GAIN control without
Set the EMISSION switch to LSB,
causing the relays to trip.
ANTIVOX GAIN at minimum, MIC GAIN at
minimum, VOX GAIN at minimum, and RF GAIN
1. The phone patch will balance on the
and AF GAIN as required for normal operation.
average telephone line with the circuit
b. Set the FUNCTION switch to CAL, and tune
capacities provided. Unusual line
in the calibrate signal to produce approximately a
conditions may require a change in
900-Hz audio tone.
capacity to compensate for these
c. Set the VOX BAL control on the Collins
conditions. If necessary, cut C7 loose,
312B -4/5 /5 fully counterclockwise.
or add the extra capacitor (furnished)
d. Lift the telephone handset, and dial a single
in parallel with C6 and C7 to produce
digit to remove the dial tone.
a null within the range of the VOX
e. Set the PHONE PATCH switch to ON.
f. Advance the VOX GAIN control on the
More precise balancing may be
transceiver until the vox relays begin to trip back
obtained if an a.c. vtvm is used.
and forth between receive and transmit positions.