Optics Housing Assembly - The optics assembly located above
the receiver includes two diffusers and an aperture.
attenuate the output pulse of the LR to a level acceptable to
the LR Tester receiver. The optics assembly located above the
transmitter consists of a lens to collimate the transmitted
optical energy from the LR Tester to the LR.
Oven Assembly - The oven assembly keeps the
temperature of the Xmt/Rcv board at 140 F (60 C).
Xmt/Rcv Board Assembly A1A1 - The Xmt/Rcv board assembly
consists of two circuits:
the transmit circuit and the
receive circuit (see figure 1-12).
The Transmit Circuit - The transmit circuit accepts an
input pulse and emits an optical pulse for each input
The Receiver Circuit - The receiver circuit receives an
input optical pulse through the PIN diode detector and
generates one or two output pulses, depending on the
received optical energy.
The electronics board assembly A2 (figure 1-11, item 14) is
controlled by the MODE switch and interfaces with the Xmt/Rcv board
assembly A1A1. It contains a dual timer circuit consisting of a 50
Hz oscillator U4A and a range timer U4B (see figure 1-13).
electronics board assembly generates either one or two output pulses
upon receiving stimulus to the input.
pulses are generated to coincide with the stimulus and output pulses.
The electronics board assembly also controls the LASER OUTPUT LOW,
DS3 and the LASER OUTPUT NORMAL, DS2 (see figure 1-13).
switch S2 resets the flip-flop circuits, which in turn is used to
reset DS2 or DS3.
The electronics board assembly provides three test points for testing
and troubleshooting. The three test points are:
TP1 monitors the output from the range timer U4B.
TP2 measures the input pulse to the range timer U4B.
TP3 monitors the output from the 2 TGT PULSE generator U1A.