TB 9-6625-2143-24
(18) If AFC is unlocked, release AFC pushbutton and repeat (5) above.
(19) Set multimeter to 100 V range.
(20) Press SCALE LOG 90 dB pushbutton and record multimeter indication.
(21) Press SCALE LOG l0 dB pushbutton and adjust A4R8 (fig. 1) for same
indication recorded in (20) above. (R)
(22) Repeat (20) and (21) above until multimeter indicates the same for both log scale
settings. Multimeter will indicate between 4.85 and 5.15 V dc.
(23) Press SCALE LOG (0 dB) pushbutton and adjust A3R3 (fig. 1) for full-scale
(0 dB) indication. (R)
(24) Set synthesizer level generator amplitude to -67.99 dBm (0.095 mV).
NOTE
To minimize extraneous pickup, place mV card nest cover over
all boards when observing -60 dB indication.
Make
adjustments, then replace cover to observe results.
NOTE
The AFC should remain locked to the -60 dB input signal. If
not, release the AFC pushbutton and manually tune for a peak
meter reading at 10 kHz.
(25) Press SCALE LOG 90 dB pushbutton and adjust A4R9 (fig. 1) for a -60 dB indication.
(26) Set synthesizer level generator amplitude to -7.45 dBm.
(27) Press SCALE LOG l0dB pushbutton and adjust A4R7 (fig. 1) for a full-scale indication. (R)
(28) Repeat (24) through (27) above until indication in (25) above is exactly -60 dB.
(29) Press SCALE LOG 90 dB pushbutton.
(30) Set synthesizer level generator amplitude to -27.45 dBm. If TI meter indicates
between -19.5 and -20.5 dB, go to (36) below. If not, record error and proceed to (31) below.
(31) Adjust A4R10 (fig. 1) until error recorded in (30) above is about 3 times its
original value. (Example: If TI meter indication is -21 dB (1 dB error) adjust A4R10
for -23 dB indication.) (R)
(32) Set synthesizer level generator amplitude to -7.45 dBm (0.0949 V).
(33) Press SCALE LOG 10 dB pushbutton and adjust A4R7 for full-scale TI indication. (R)
(34) Repeat (29) through (33) above until indication in (30) above is between - 19.5
and -20.5 dB.
(35) Repeat (24) through (30) above.
(36) Press SCALE VOLTS pushbutton.
(37) Set synthesizer level generator amplitude to -6.99 dBm (0.1 V rms) and adjust
A4R6 (fig. 1) for full-scale indication. (R)
(38) Set INPUT SENSITIVITY switch to CAL position. (AFC should lock TI to
10 kHz signal.)
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