TM 11-6625-596-45
CHAPTER 4
REPAIRS AND ALIGNMENT
4-1.
General Parts Replacement Techniques
material from the part to be replaced with a hot
a. Most parts of the TS-716/U are readily
accessible and are replaced using conventional repair
(3) When diodes or transistors are to be
installed, use approximately the same length and dress
locating parts and making repairs.
of leads as used originally.
b. Use a pencil-type iron with a 25-watt maxi-
(4) If the copper foil peels off the bottom
mum capacity for transistorized circuits. When a high
of the board during repair, discard the board.
temperature iron is to be used for installing diodes and
transistors, grasp the lead between the soldering iron
d. Repair or replacement of the following units
and the component with a pair of long-nose pliers. This
requires recalibration of portions of the test set circuitry.
protects the component from excessive heat. If the iron
(1) If test loudspeaker 1A2A2 is replaced,
between the iron and the line. Check the iron for shorts-
(2) If microphone 1A2A4A4 or capicitor
to the tip before it is used. See TB SIG-222.
1A2A14C1 is replaced, adjust 1A2A14R2 (, para 4-5).
c. If printed boards are to be repaired, note
(3) If meter amplifier 1A3A2 is repaired or
the following precautions:
(4) If dial break board 1A3A9 is repaired
(2) Remove the conformal coating
4-2.
Test Equipment Required for Alignment
Test equipment
Technical manual
Common name
Signal Generator TS-382/U-----------------------------
TM 11-6625-261-12-----------
Voltmeter ME-30/U----------------------------------------
TM 11-6625-320-12-----------
TM 11-6625-535-15-----------
Oscillcscope.
Calibrated microphone flat within -2 dB, 200 to 6, 000 Hz
Sound level meter.
Capable of measuring sound pressure of 28 dynes/cm'
and General Radio Sound Level Meter Model 1551C or
equivalent.
4-3.
d. If
necessary,
readjust
NOISE
GENERATOR control 1A4R12 to bring the needle of
a. Start the test set as described in TM 11-
meter 1A4M1 back to the red CAL mark.
6625-596-12.
e. Repeat c and d above as many times as
b. Depress NOISE GEN ADJ button 1A136A
necessary until the sound pressure at the screen of the
and vary NOISE GENERATOR control 1A4R12 until
test loudspeaker is 28 dynes/cm2 when the needle of
meter 1A4M1 reads at the red CAL mark.
meter 1A4M1 rests on the red CAL mark.
c. Holding the standard microphone at the
screen of test loudspeaker 1A2A2, adjust 1A3R11 until
4-4.
Meter Amplifier Gain Adjustment 1A3R16
the ground pressure at the screen of the test
loudspeaker is 28 ynes/cm2 (103 dB + 1 dB -0 dB).
a. Start the test set as described i-n TM 11-
6625-596-12.
4-1