TB 9-6625-160-24
11. Distortion and Noise
a. Performance Check
(1) Press TI numerical key for 41.0 and then SPCL key to initialize TI.
NOTE
For 8903B (S/N below 2742), use the impedance switch to set
the proper impedance. For 8903B (S/N 2742 and above), 47.0
SPCL sets impedance to 600 Ω and 47.1 SPCL sets impedance
to 50 Ω. Verify the IMPEDANCE light is either on or off for
50 Ω or 600 Ω respectively.
(2) Set TI INPUT and OUTPUT FLOAT switches to ground. Set IMPEDANCE to 50 Ω.
(3) Connect TI OUTPUT HIGH connector to INPUT HIGH connector through 50 Ω
feedthrough termination.
(4) Set TI SOURCE FREQ and AMPTD to first set of values listed in SOURCE
Freq and Amplitude columns of table 14.
(5) Set TI MEASUREMENT mode and LP FILTER switches to first corresponding
positions listed in table 14. (For DISTN, set LOG/LIN switch to read in dB.)
(6) TI right display must indicate within values listed in Limits column of table 14.
(7) Repeat technique of (4) through (6) above for each remaining values listed in
Table 14. Residual Distortion and Noise.
Source
Measurement
Limits (dB)
Freq (Hz)
Amplitude (V)
Mode
LP Filter
Minimum
Maximum
20
6.0
DISTN
80 kHz
- 80
1k
6.0
DISTN
80 kHz
- 80
1k
5.0
DISTN
80 kHz
- 80
1k
3.8
DISTN
80 kHz
- 80
1k
0.6
DISTN
80 kHz
- 80
1k
0.6
SIG/NOISE
80 kHz
+ 85
20 k
6.0
DISTN
80 kHz
- 80
50 k
6.0
DISTN
OFF
- 70
50 k
0.6
DISTN
OFF
- 70
50 k
0.6
SIG/NOISE
OFF
+ 70
100 k
6.0
DISTN
OFF
- 65
100 k
5.0
DISTN
OFF
- 65
100 k
3.8
DISTN
OFF
- 65
(8) Set TI SOURCE AMPTD to 0 V and disconnect test setup.
b. Adjustments. Perform adjustments in paragraph 17 below.