To test IC amplifier 1 (IA1SA A5)

TM 11-6820-695-35

MODULE TEST press-to-test switch. If the output signal

grounds the 4.02 kHz monitor input thus removing its

level of amplifier 1 is normal, the lamp driver is biased

output voltage. This causes the lamp driver to be

off. Thus, the MODULE TEST indicator is extinguished

biased on and the MODULE TEST indicator conducts

indicating amplifier 1 is operating normally. However, if

and glows red.

the output signal level of amplifier 1 is low, the 4.02 kHz

c. To test IC amplifier 1 (IA1SA A5), the MODULE

monitor cannot develop a dc voltage sufficient to bias

TEST selector switch is set to position 2, connecting the

the lamp driver off. With the lamp driver biased on, the

4.02 kHz oscillator output signal through selector switch

MODULE TEST indicator lights red indicating that

contact S1C-2 to one input IC amplifier 1. This signal is

amplifier 1 is defective.

designated +4.02 kHz. The 4.02 kHz oscillator output

signal is also connected through transformer Ti. and

d. Amplifiers 2 through 6, the peak limiters, and

selector switch contact SID-2 to the output input of

the speaker amplifier are tested in the same manner as

amplifier 1. Transformer T1 reverses the phase of the

described above for amplifier 1. The selector switch

signal which is designated -4.02 kHz. The output signal

positions and input and output contacts associated with

level of amplifier 1' is applied to 4.02 kHz monitor Q2

each test are listed in the following chart.

through contact S18-2 of the selector switch and the

is set to position 11. Ground is applied to the oscillator

e. To test 1.6 kHz oscillator 1A13A5Q1, the

input through S1E-6 and SlE-11 causing the oscillator to

MODULE TEST selector switch is set to position 10

provide a 1.1 kHz tone output through IC amplifier

which connects ground to the oscillator input through

1Al1OA2A1. The 1.1' kHz tone signal is connected to

91E-2 and S1E-10.

With its input grounded the

the 1.1/1.6 kHz input of the 4.02 kHz monitor by the

oscillator starts to oscillate and provides 1.6 kHz tone

TEST TONE switch, emitter follower Q6 and IC

output through IC amplifier l'A13A5A1. The tone signal

amplifier A2 on board No. 2 lAr3&A2, and selector

is connected to the 1'.1/1.6 kHz input of 4.02 kHz

switch contact SlA-11.

monitor lA13AIQ2 through emitter follower Q5 and IC

amplifier A2 on 1A13A2, and contact SlA-10 of the

g. To test the central alarm monitor circuit on

selector switch. If the 1.6 kHz oscillator and emitter

meter panel assembly 1A15A8 and the monitor circuit

follower Q5 are operating normally (IC amplifier

on IA13A.2, the MODULE TEST selector switch S1 is

1A13A2A2 was tested for normal operation in position 9

set to position 12. Sections SlE and SIE-12 apply

of the selector switch), the MODULE TEST indicator

ground to simulate power amplifier alarm input OR

should be extinguished. If the 'l.6 kHz oscillator and/or

gates A and B on

emitter follower Q5 are not operating normally, the

MODULE TEST indicator will light red.

f. The 1.1 kHz oscillator lA'13A2Q7 is tested in a

manner similar to that described above for the 1.6 kHz

oscillator except that the MODULE TEST selector switch

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