TB 9-6625-1998-24
Table 4. Frequency - Continued
Test instrument
Audio analyzer indications
FREQ RANGE
FREQUENCY
MULTIPLIER
Min
Max
dial settings
switch settings
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. 2) 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.
(4) Reposition frequency dial to indicate 200.
NOTE
Remove frequency dial knob and loosen set screws to reposition
dial to 200. Tighten set screws after repositioning dial.
(5) Set frequency dial in turn to 100, 60, 40, and 20. If audio analyzer does not
indicate within 2 percent of settings, repeat (1) through (4) above for best in-tolerance condition.
(6) Repeat a (4) above. If audio analyzer does not indicate within limits specified,
perform (7) through (15) below.
(7) Set C14 (fig. 2) to the half-open position.
(8) Set FREQ RANGE MULTIPLIER switch to X1K and frequency dial to 20.
(9) Adjust C5 and C13 (fig. 2) until audio analyzer indicates 20.000 kHz (R).
(10) Turn OUTPUT CONTROL fully cw.
(11) If required, readjust C5 and C13 (fig. 2) until OUTPUT RMS meter indicates at
least 1.15 and audio analyzer indicates 20.000 kHz.
8
