receiver-transmitter and external noise from being
an aid to fault isolation. The meter consists of a 12-
conducted out of the receiver-transmitter by wiring to the
position selector switch (A10A1S2) and a meter circuit
radio set. In addition, all audio and data lines (J22-A
composed of dc milliameter A10A1M1, resistor
through F and J22-L through S) that enter and leave
A10A1R8, and diodes A10A1CR1 and A10A1CR2.
Diodes A10A1CR1 and A10A1CR2 provide protection to
through A10A3CR16, A10A3VR1, and A10A3VR2) that
the 0- to 1-milliampere dc milliameter from application of
provide protection to the receiver-transmitter from
excessive voltage by shunting excess current around the
destructive transient voltages or spikes.
dc mllliameter when the voltage drop across A10A1R8 in
series with A10A1M1 exceeds about 200 millivolts. To
4-307. TEST POINTS. Refer to figure FO-33 and to
measure voltage, resistors located in the voltage
figures FO-14, FO-15, and FO-16.
regulator and power amplifier modules are selected by
A10A1TP1 through A10A1TP14 provide front panel
A10A1S2. These resistors limit current through the
access to signals within the receiver-transmitter and can
meter in proportion to the voltage being measured to
be used to monitor system performance or as an aid to
provide the proper indication on the meter scale. Meter
accuracy is about 5 percent for voltage measurements
signals monitored by each test point.
and about 10 percent for power and percent modulation
4-308. METER. Refer to figure FO-33. The meter
provides indication of power supply voltages and signal
levels within the receiver-transmitter and can be used to
signals measured by each position of the selector switch.
monitor system performance or as