TB 9-6625-2088-24
11. Sine Distortion
a. Performance Check
(1) Connect audio analyzer to FUNCTION OUT using 50
feedthrough termination.
(2) Position controls as listed in (a) through (c) below:
(a) FUNCTION switch to (sine).
(b) FREQ/PERIOD MULTI (Hz/s) switch to 1 K and VERNIER control to CAL.
(c) Frequency dial to 1.0.
(3) Measure distortion at 1 kHz. If audio analyzer does not indicate less than 0.5
percent distortion, perform b (2) and (3) below.
(4) Set FREQ/PERIOD MULTI (Hz/s) switch to 100K.
(5) Measure distortion at 100 kHz. If audio analyzer does not indicate less than 1
percent distortion, perform b below.
b. Adjustments
(1) Repeat a (2) above.
(2) Connect oscilloscope to audio analyzer output. Sync oscilloscope with SYNC
OUT using 50 feedthrough termination.
(3) Adjust R120 (fig. 2) for symmetrical wave form as indicated on oscilloscope.
(4) Slightly adjust R93 and R107 (fig. 2) for minimum distortion.
(5) If R93 or R107 (fig. 2) is adjusted near a stop, recenter both adjustments and
repeat paragraph 9 above.
12. Frequency
a. Performance Check
(1) Adjust ATTENUATION VERNIER control to midrange and set FUNCTION
switch to (sine).
(2) Connect frequency counter to FUNCTION OUT.
(3) Position controls to values listed in table 4.
If frequency counter does not
indicate within limits specified, perform b below.
Table 4. Frequency
Test instrument
Frequency counter indications
FREQ/PERIOD MULTI
Frequency dial
(Hz/s) switch settings
settings
Min
Max
.01
2.0
48.50
s
51.50
s
.1
2.0
4.850
s
5.150
s
1
2.0
0.485
s
0.515
s
10
2.0
48.50
ms
51.50
ms
