TM 11-6625-586-45
y. Turn BAND SWITCH to B and select fre-
n. Check output voltage at E29 with oscillo-
quency of 32 MHz.
scope. It should be greater than 2.5 volts rms.
o. Turn FUNCTION switch to 400 HZ.
z. Turn DEVIATION CAL control R38 fully
p. Adjust 400 HZ ADJ R18 for 400 HZ indi-
clockwise.
cation on electronic counter.
aa. Check reading on external deviation meter.
q. Connect test equipment to signal generator
If greater than 48 kHz; repeat steps w and x .
as shown in figure 55.
ab. Readjust R38 for 38 kHz indication on
external deviation meter.
below.
ac. Turn FUNCTION switch to 1000 HZ. Ad-
Switch
Position
j u s t DEVIATION control for DEVIATION
DEVIATION RANGE KHZ 40
metier reading of 40 kHz.
RF OUTPUT
62.5 KUV
ad. Measure and record for future reference
BAND SWITCH
A
the external deviation meter reading and the dis-
RF TUNING
22 MHz
tortion at band B center frequency of 32 MHz
and end frequencies of 26 and 38 MHz.
required in accordance with the following chart:
ae. If distortion is greater than 3%, increase
Band
Frequency
Bias
Adjustment
bias 0.4 volts with R28 and repeat step ad above.
A
22
8.25
0.1
volt
R29
af. Interpret results using guide lines given in
B
32
11.05
0.1
volt
R28
45
C
10.1
0.1
volt
R27
D
67
10.4
0.1
volt
R26
ag. After a satisfactory bias level has been de-
termined for band B, calibrate bands A, C and D,
t. Turn DEVIATION control fully clockwise.
in that order. The recommended starting points
are given in the following chart:
Hz output at 2 volts rms.
v. Adjust DEV METER CAL control R29 for
Adjustment
Band
RF frequency
Deviation setting
40 kHz indication on DEVIATION meter.
R37
22
MHz
39
kHz
A
w. Turn DEVIATION control for reading of
R38
32
MHz
38
kHz
B
35 kHz on DEVIATION meter.
R39
45
MHz
38
kHz
C
x. Repeat step v.
R40
D
67
MHz
39
kHz
Table 5-5. Internal Modulation Deviation and Distortion Check.
Change 1
5-9
