TB 9-6695-288-35
Example
Determine the difference in amplitude of second harmonic in
(12) above and third harmonic in (13) above. Add dB number
in figure 4 to largest value of harmonic amplitude.
(16) Induced distortion will be <-95 dB.
(17) Repeat technique of (1) through (16) above for fundamental rejection and
induced distortion measurements using settings listed in table 8. Fundamental rejection
and induced distortion indications will be within limits specified.
Test instrument
Oscillator settings and
Fundamental rejection
Induced distortion
FREQUENCY switch
spectrum analyzer center
indications (dB)
indications (dB)
settings
frequency
2.0 x 10
20 Hz
>-100
<-95
1.0 x 100
100 Hz
>-100
<-95
1.0 x 10K
10 kHz
>-100
<-95
2.0 x 10K
20 kHz
>-100
<-95
3.0 x 10K
30 kHz
>-90
<-90
5.0 x 10K
50 kHz
>-90
<-85
10.0 x 10K
100 kHz
>-83
<-70
b. Adjustments
(1) Adjust A4R16 NOTCH FILTER NULL ADJUST and A4R43 NOTCH
analyzer (R).
(2) Set FUNCTION switch to INPUT LEVEL and FREQUENCY switches to 2.0 x
10.
(3) Set oscillator to 20 Hz and a full scale indication on TI meter (1 on 0 - 1 scale).
indication on spectrum analyzer (<-95 dB including DISTORTION RANGE switch
setting) (R).
(5) Repeat a(1) through (10) above.
14. Distortion Accuracy
a. Performance Check
(1) Connect equipment as shown in figure 5.
NOTE DELETED
CHANGE 1 15
