TB 9-5915-214-35
k. Press corresponding keys as listed in (1) through (5) below and verify CUTOFF
FREQUENCY indicates 2.100.
(1)
2 data entry key.
(2)
. data entry key.
(3)
1 data entry key.
(4)
KILO parameter key.
(5)
FREQ parameter key.
l.
Adjust calibrator for a 2.1 kHz output.
indication or split the difference between the two readings.
n. Press MODE parameter key until CUTOFF FREQUENCY display indicates L.P.
o. Set calibrator and TI frequencies for a 256 kHz output, using technique of c above to
enter TI frequency. If true rms voltmeter does not indicate -3 dB, adjust C234 (fig. 2) until
true rms voltmeter indicates -3 dB.
p. Alternate calibrator and TI frequencies between 25 kHz and 250 kHz using
technique of c above to enter TI frequency. Adjust R228 (fig. 2) for a -3 dB true rms
voltmeter indication or split the difference between the two readings.
q. Press MODE parameter key until CUTOFF FREQUENCY display indicates h.P.
r. Set calibrator and TI frequencies for a 256 kHz output, using technique of c above to
enter TI frequency. If true rms voltmeter does not indicate -3 dB, adjust C204 (fig. 2) until
true rms voltmeter indicates -3 dB.
s. Set calibrator and TI frequencies for a 2 MHz output, using technique of c above to
enter TI frequency, but press MEGA instead of KILO. If true rms voltmeter does not
indicate between -2.36 and -3.75 dB, readjust C204 (fig. 2) until true rms voltmeter
indicates between -2.36 and -3.75 dB.
t.
Press MODE parameter key until CUTOFF FREQUENCY display indicates L.P.
u. Set calibrator and TI frequencies for a 256 kHz output, using technique of c above to
enter TI frequency. Verify true rms voltmeter indicates between -2.36 and -3.75 dB.
v. Set calibrator and TI frequencies for a 2 MHz output, using technique of c above to
enter TI frequency, but press MEGA instead of KILO. If true rms voltmeter does not
indicate between -2.36 and -3.75 dB, readjust C234 (fig. 2) until true rms voltmeter
indicates between -2.36 and -3.75 dB.
w. Set calibrator and TI frequencies for a 256 kHz output, using technique of c above to
enter TI frequency. Verify true rms voltmeter indicates between -2.76 and -3.29 dB.
x. Repeat technique of a through w above for CH 2.