TB 9-6625-2343-40
(57) Adjust calibrator output for a TI indication of the product of the following:
(10 kHz peak deviation multiplied by the 40 kHz ref value recorded in (9) above).
(58) Press calibrator NEW REF key.
(59) Change calibrator output frequency to 10 kHz.
(60) If TI does not indicate within limits specified in first row of table 8, perform b below.
(61) Repeat technique of (59) above for remaining calibrator frequency listed in table 8.
If TI indications are not within limits specified, perform b below.
Table 8. 455 kHz IF Accuracy
Test instrument
Calibrator
indications
frequency
(kHz)
Output
Min
Max
10 kHz
9.79
10.21
20 Hz
9.79
10.21
(62) Change calibrator output frequency to 10 kHz at an amplitude of 400 mV.
(63) Adjust calibrator output for a TI indication of 10 kHz peak deviation.
(64) Set audio analyzer for a DISTORTION measurement with 30 kHz low pass and
400 Hz high pass filters activated.
(65) If audio analyzer does not indicate ≤ 0.1%, perform b below.
(66) Reduce all outputs to minimum and disconnect equipment setup.
b. Adjustments
(1) Disconnect equipment setup.
(2) Connect TI sensor module to signal generator No. 1 RF OUTPUT.
(3) Connect oscilloscope Vertical 1 input to A23TP1 SMPL AMPL (fig 7).
(4) Set signal generator No. 1 for an output of 18 MHz at a level of 0 dBm.
(5) Set oscilloscope for the following:
(a) Vertical 1 Coupling to AC.
(b) Vertical 1 scaling to 200 mV.
(c) Sweep speed to 10 s.
(6) Press TI keys as listed in (a) through (c) below:
(a) INSTR PRESET.
(b) DATA 18 MHz.
(c) TRACK MODE.
(7) Fine tune signal generator No. 1 up slowly until a zero beat appears on
oscilloscope. Then increase signal generator No. 1 frequency by 1 kHz. Record the
oscilloscope peak to peak amplitude as PK#1.
(8) Increase signal generator No. 1 frequency by 30 kHz.
(9) Adjust A23R33 OFS (fig. 7) such that when the oscilloscope input coupling is
changed from ac to dc the waveform shifts upward 50 mV. Adjust only when the input
coupling is set to dc. (R)
19