TB 9-6625-1998-35
9. Frequency
a. Performance Check
(1) Connect OUTPUT to audio analyzer INPUT high.
(2) Set ATTENUATOR switch to X1V and adjust TI OUTPUT CONTROL for 1.0
on OUTPUT RMS (VOLTS RMS) meter.
(3) Set FREQ RANGE MULTIPLIER switch to X1K and frequency dial to 200. If
audio analyzer does not indicate between 196.000 and 204.00 kHz, perform b below.
(4) Repeat technique of (3) above at FREQ RANGE MULTIPLIER switch and
frequency dial settings listed in table 4. If audio analyzer does not indicate within limits
specified, perform b below.
Table 4. Frequency
Test instrument
Audio analyzer indications
FREQ RANGE
Frequency
MULTIPLIER
dial settings
Min
Max
switch settings
X1K
100
98.000
kHz
102.000
kHz
X1K
20
19600.0
Hz
20.400
kHz
X100
20
1960.00
Hz
2040.0
Hz
X100
100
9800.0
Hz
10200.0
Hz
X100
200
19600.0
Hz
20.400
kHz
X10
200
1960.00
Hz
2040.0
Hz
X10
100
980.00
Hz
1020.00
Hz
X10
20
196.000
Hz
204.00
Hz
X1
20
19.600
Hz
20.400
Hz
X1
100
98.000
Hz
102.000
Hz
X1
200
196.000
Hz
204.00
Hz
b. Adjustments
NOTE
Perform (1) through (15) for AN/URM-127.
Perform (16)
through (26) for AN/URM-127A.
(1) Set FREQ RANGE MULTIPLIER switch to X100 and frequency dial fully ccw
to mark on dial.
(2) Adjust C11 (fig. 1) until audio analyzer indicates between 21.400 and 21.500
kHz (R).
(3) Slowly rotate frequency dial cw until audio analyzer indicates 20.000 kHz.
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