Procedural Step (Cont):
d. Turn the SQUELCH CONTROL KNOB (2) counterclockwise (off).
Turn the VOLUME CONTROL KNOB (16) all the way clockwise.
f . Turn the VOLTAGE CHECK/OPERATE SWITCH (28) to the receiver circuits
portion of the scale; 1,2B (approximately the one o'clock position).
g. Turn the power source on. The input voltage to the R-123M power supply
should be 24 + 1 vDC for best operation.
h. Turn the POWER SWITCH (23) and the DIAL LIGHT SWITCH (26) to the on (up)
position. At this time the FREQUENCY DIAL VIEWING WINDOW (5) and the
INDICATOR METER (12) will light. After the tubes are heated, a rushing noise will be
heard in the earphones. Adjust the VOLUME CONTROL KNOB (16) for the desired