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5-5 seA DEMODULATOR ALIGNMENT (A6
Assembly)
1.
Complete ali9nment of A2 assembly (Section 5-2) and A3 assembly
(Section
5-3).
2.
Apply an input signal of 67000
Hz
into the COMP IN (AIJ13).
Adjust input level until MOD PEAK lamp just lights at 100% ..
3.
Reduce input level by exactly 20 dB.
4.
Depress
SeA I NJ.
NARROW
t
t~
I N
but ton on
D I SPLAY SEL EeT
swi tch
(AISll) .
5.
Adjust
A6R9
until
CH.A
meter (AIM2A) reads 100%.
This is equal
to 10%
SCA
injection.
6.
Depress
SCA INJ. WIDE,
SeA MOD button on
DISPLAY SELECT
switch
(AlS
11).
7.
Adjust
A6R25
until
CH.A
meter (AIM2A) reads 100%.
This is
equal to 10%
SeA
injection.
8.
Connect a scope probe to A6U2-9.
Adjust A6R33 until signal on
A6U2-9
locks onto incoming 67 KHz.
9.
Reduce SeA injection to 3%.
Adjust A6R39 until
SeA PRESENT
lamp
(AIDS4)
just lights.
10.
Connect your
SeA
generator to the
COMP
IN (AIJ13).
Adjust
COMP
LEVEL
(AIR4) for 10% injection.
11.
Depress
SCA INJ.
NARROW, MAIN button on DISPLAY
SELECT
switch
(A1Sl1).
Place OEV switch (AlS9) in 4 KHz position.
12.
Modulate the
SCA
generator with a frequency of 1660 Hz.
Increase
the audio input until the
CH.A
meter
(AIM2A)
nulls for the first
time.
NOTE:
This is a Bessel null function for 4KHz deviation.
13.
Depress
SeA INJ. WIDE, seA MOD
button on
DISPLAY
SELECT switch
(AlSll) .
14.
Adjust
A6R15
until
CH.B
meter
(AIM2B)
reads
100%.
5-6 RECEIVER ALIGNMENT (A4 Assembly)
1.
Complete alignment of
A2
assembly (Section 5-2), A3 assembly
(Section 5-3),
A5
assembly (Section 5-4), and
A6
assembly
(Section
5-5).
2.
LOG
AMP ALIGNMENT
a.
Put probe from DC coupled scope on A4U6-6.
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