TB 9-6625-2271-40
Table 7. Distortion Measurement Accuracy at -40 dB
Test instrument
Test instrument indications
SOURCE FREQ
(dB)
settings
Min
Max
21
Hz
-41
-39
1
kHz
-41
-39
19.99 kHz
-41
-39
21
kHz
-42
-38
50
kHz
-42
-38
100
kHz
-42
-38
(8) Connect calibrator OUTPUT HI and LO to TI INPUT LOW.
(9) Set calibrator for a 0.1 V, 222 Hz output. Repeat technique of (5) above using TI
SOURCE FREQ settings and indications listed in table 8.
Table 8. Distortion Measurement Accuracy at -20 dB
Test instrument indications
Test instrument
SOURCE FREQ
(dB)
settings
Min
Max
21
Hz
-21
-19
1
kHz
-21
-19
19.99 kHz
-21
-19
21
kHz
-22
-18
50
kHz
-22
-18
100
kHz
-22
-18
b. Adjustments
NOTE
The adjustments provided are for the notch filter. These
adjustments will not affect distortion accuracy; however,
capability will be enhanced by lowering residual distortion.
Perform the following only if TI indications are high.
(1) Connect TI OUTPUT HIGH to INPUT HIGH and OUTPUT LOW to
INPUT LOW.
(2) Press keys and enter values using DATA ENTRY keys as listed in (a) through
(d) below:
LCL INIT.
(a)
SOURCE LEVEL.
(b)
3 V.
(c)
ANALYZER DIST.
(d)
(3) Adjust A2R57 and A2R58 (fig. 4) for minimum distortion indication on TI.
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