TB 9-6695-263-35
(5) Connect calibration fixture FM 4 output to TI INPUT.
(7) Set calibrator for a wideband output frequency of 10 kHz at an amplitude of 0.5 V.
(8) Press MEASUREMENT FREQ pushbutton.
(10) Position TI controls as listed in (a) through (d) below:
(a)
MEASUREMENT FM pushbutton pressed.
(b)
LP FILTER 15 kHz pushbutton pressed.
(c)
2.0 SPCL pushbuttons pressed.
(d)
DETECTOR AVG. pushbutton pressed.
(11) Adjust calibrator output for a 20 kHz average deviation as displayed on TI.
(12) Press TI RATIO % pushbutton.
(13) Move connection to FM 32 OUTPUT without disturbing calibration fixture
controls. Multiply displayed ratio by value recorded in (2) above. Result will be between
12.35 and 12.65 percent REL.
b. Adjustments.
Adjust A4R50 FM
SENS (fig. 1) for a
100 percent indication on TI
display (R).
16. FM Distortion, Accuracy, and
Rejection at
1.5 MHz IF
a. Performance Check
(1) Connect equipment as shown in figure 2, except connect calibration fixture FM
4 OUTPUT to TI INPUT.
(2) Position TI controls as listed in (a) through (c) below:
(a) HP and LP FILTER pushbuttons pressed to off.
(b) DETECTOR PEAK + (positive) pushbutton pressed
(c) RATIO pushbuttons pressed to off.
(3) Set calibrator for a wideband output frequency of 100 kHz at an amplitude of
370 mV.
(4) Adjust calibrator output for a 100 kHz indication on TI display.
(5) Measure distortion on audio analyzer with all filters off. If audio analyzer does
not indicate 0.1 percent or less distortion, perform b below.
(6) Adjust calibrator frequency to 10 kHz and output level for TI display equal to
100 kHz times calibration factor recorded in a 15 a (2). (For example, if calibration factor
in 15 a (2) is 100.4 percent, set output level for display of 100.4 kHz.).
(7) Adjust calibrator to frequencies listed in table 4. TI display will indicate within
limits specified.