TB 9-6625-2076-35
a. Performance Check
NOTE
Since all of the audio tones are derived from the same reference
crystal, only the accuracy of one tone is checked.
(1) Connect frequency counter to TI COMP (rear panel).
(2) Enter a frequency of 108.000 MHz into TI and press TONE SELECT 9960 Hz
pushbutton (all other TONE SELECT pushbuttons off).
(3) Measure period of 9960 Hz tone. Frequency counter will indicate between
100.39658 and 100.40662 s. If not, perform b below.
b. Adjustments. Adjust A2A3C7 (located on left side of TI, top front of board A2A3)
for a 100.4016 s frequency counter indication (R).
a. Performance Check
(1) Connect audio analyzer to TI COMP (rear panel).
(2) Measure distortion, using standard measurement techniques. Distortion will be
0.5 percent or less.
(3) Repeat technique of (2) above for TI frequencies and indications listed in table 7.
Distortion will be within limits specified.
Test instrument
Distortion analyzer
Frequency (MHz)
TONE SELECT (Hz)
maximum distortion (%)
108.00
1020
0.5
332.00
90
0.25
332.00
150
0.25
75.00
400
1.0
75.00
1300
1.0
75.00
3000
1.0
a. Performance Check
(1) Position oscilloscope controls as listed in (a) through (d) below:
(a) VERTICAL MODE to CH1 vs CH2 and XY.
(b) CH1 and CH2 VOLTS/DIV to .5 V.
(c) CH1 and CH2 COUPLING/INVERT t
