TB 9-6625-2184-35
9. Frequency Accuracy, Stability and UNBAL Response
a. Performance Check
(1) Connect equipment as shown in figure 3.
TI
VOLTAGE DIVIDER
TRUE RMS VOLTMETER
FREQUENCY COUNTER
(2) Position controls as listed in (a) through (c) below:
(a) MOD. BAL. - BAL. - UNBAL. switch to UNBAL.
(b) RANGE switch to X1.
(c) AMPLITUDE FINE and COARSE controls fully cw.
(3) Adjust frequency dial to 50. True rms voltmeter will indicate at least 6 V.
perform b (1) through (3) below.
(5) Repeat (3) and (4) above with TI RANGE switch set to X10, X100, and X1000.
(6) Adjust AMPLITUDE FINE and COARSE controls fully ccw.
(7) Adjust frequency dial to 50 and set RANGE switch to X1.
(8) Readjust AMPLITUDE COARSE and FINE controls until true rms voltmeter
indicates 0 dB. Frequency counter will indicate between 19.60 and 20.40 mS.
(9) Adjust frequency dial to 500. True rms voltmeter will indicate between -1 and
+1 dB. If frequency counter does not indicate between 490 and 510 Hz, perform b (4) and
(5) below.