shall be squelched. Increase the signal generator
(c) A VC characteristic check. With the equip-
output to a point which just opens the squelch. The
ment connected as shown in figure 3, vary the sig-
signal level shall be between 1 and 4 microvolt. If
nal generator input level from 10 to 100,000 micro-
these results are not obtained, adjust the signal
volts. The audio output shall not vary more than ±
generator output to the level which produces a 6 db
3 db from the 1,000 microvolt reference valve. The
signal-plus-noise to noise ratio and adjust the re-
ceiver squelch resistor A7R51 for squelch threshold.
same check shall be made for the guard receiver
and the same values shall apply.
Reject the equipment if this adjustment cannot be
Figure 1. Equipment and test units for making
power output and sidetonr measurements.