Product: 492/492P Service Vol. 1 Date: 5-2-84
Change Reference: C1Q1/584
DESCRIPTION
d. The DC503A readout should indicate approximately 110.000 MHz. Adjust
evel as necessary» and adjust the 7L14 Center Frequency for an indication of
10. 0 MHz.
e. Set the 7L14 Time/Div to calibrated display.
f. Adjust variable capacitors C1016» C1020 and C1024 for maximum amplitude»
symmetry and bandpass O d B and 6dB points).
1. Adjust the bandwidth symmetry +/- 0.5 divisions (+/- 0.5 MHz) at the
3 dB and 6 dB points.
NOTE
Check that points 3 dB (1.5 divisions) and 6 dB
(3 divisions) down from the top of the signal
are equidistant (+/- 0.5 divisions) from center
screen.
2. Check that bandwidth at the 3 dB point is 7. 5 MHz. +/- 1. 5 MHz.
3. Check that any ripple present on the waveform is </= 0.2 div
.4 dB).
NOTE
A slight change in display may be observed when
the cover is reinstalled on the module.
g. Check the Coupled Forward Gain (IF OUT port - P1024)
1. Set the 7L14 Spectrum Analyzer Reference Level to 0 dBm.
2. Check that the display on the 7L14 is between 4 and 7 divisions
'n amplitude (-5 dBm» +/—3 dBm).
h. Check the Input Compression.
1. Set the TR503 Output Level and 494 REFERENCE LEVEL in one dB
increments» to higher power level (-24 dbm» -23 dBm etc. )
m .
2. Continue changing the power level until the signal displayed by
e 7L14 amplitude decreases (compresses 1 dB) 0.5 division.
3. Check that the signal displayed on the 7114 indicates >/= 0 dBm
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