TB 9-5915-214-35
w. Alternate calibrator and TI frequencies between 25 kHz and 250 kHz using
technique of f above to enter TI frequency. Adjust R160 (fig. 1) for a -5.33 dB true rms
voltmeter indication or split the difference between the two readings.
x. Repeat p through t above.
y. Repeat technique of a through x above for CH 2.
17. Passband Unity-Gain
a. Connect calibrator to INPUT CH 1 using 50 : termination.
b. Connect true rms voltmeter to OUTPUT CH 1.
c. Press MODE parameter key until CUTOFF FREQUENCY display indicates bYP.
d. Press corresponding keys as listed in (1) through (4) below and verify CUTOFF
FREQUENCY indicates 25.00.
(1) 2 data entry key.
(2) 5 data entry key.
(3) KILO parameter key.
(4) FREQ parameter key.
e. Adjust calibrator for a 200 Hz, 1 V output and reference true rms voltmeter to 0 dB.
f. Press MODE parameter key until CUTOFF FREQUENCY display indicates L.P.
If true rms voltmeter does not indicate 0 dB, r0.01 dB, adjust R250 (fig. 1) until true rms
voltmeter indicates 0 dB, r0.01 dB.
g. Press corresponding keys as listed in (1) through (4) below and verify CUTOFF
FREQUENCY indicates 256.0.
(1) 2 data entry key.
(2) 5 data entry key.
(3) 6 data entry key.
(4) FREQ parameter key.
h. Press MODE parameter key until CUTOFF FREQUENCY display indicates bYP.
i. Adjust calibrator for a 10 kHz, 1 V output and reference true rms voltmeter to 0 dB.
j. Press MODE parameter key until CUTOFF FREQUENCY display indicates h.P.
If true rms voltmeter does not indicate 0 dB, r0.01 dB, adjust R251 (fig. 1) until true rms
voltmeter indicates 0 dB, r0.01 dB.
k. Repeat technique of a through j above for CH 2.
18. Output Frequency Response
a
Press MODE parameter key until CUTOFF FREQUENCY display indicates h.P.
b. Press corresponding keys as listed in (1) through (3) below and verify CUTOFF
FREQUENCY indicates 2.000.
(1) 2 data entry key.