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489 RBW 100
490 RBW 100
491 RBW
C300
492 RBW 300
493 RBW
1K
494 RBW 3K
495 RBW
10K
496 RBW
100
497 RBW
100
498 RBW
100
499
CAL
UNLK
Unable to adjust 100 Hz resolution bandwidth.
Unable to adjust 100 Hz resolution bandwidth.
Unable to adjust the resolution bandwidths less than 300 Hz. Crystal
sweep gain problem.
Unable to adjust 300 Hz resolution bandwidth. Crystal sweep gain
problem.
Unable to adjust 1 kHz resolution bandwidth. Crystal sweep gain
problem.
Unable to adjust 3 kHz resolution bandwidth. Crystal sweep gain
problem.
Unable to adjust 10 kHz resolution bandwidth. Crystal sweep gain
problem.
Unable to adjust 100 Hz resolution bandwidth. Inadequate Q.
Unable to adjust 100 Hz resolution bandwidth. Alignment problem.
Unable to adjust 100 Hz resolution bandwidth. Gain problem.
Cal oscillator is unlocked. Verify the unlocked conditions as follows:
1. Place A4 in its service position and disconnect W51 (gray-yellow)
from A4J7.
2. Connect W51 to the input of another spectrum analyzer. This is
the 10 MHz reference for the cal oscillator.
3. If a 10 MHz signal (approximately 0
dBm)
is not present, suspect
the Al5 RF assembly, the A21 OCXO, or the Al5 assembly TCXO
(Option 103). If the 10 MHz reference is present, continue with
step 4.
4. Reconnect W17 to A4J7 and monitor the tune voltage at
A4J9 pin 3 with an oscilloscope.
5. Press
(PRESET)
on the spectrum analyzer under test.
6. If the voltage is either
+15
Vdc or -15 Vdc, the Cal Oscillator is
probably at fault. Normally, the voltage should be near
+15
V
during a sweep, and between -9 V and
+9
V during retrace.
An intermittent error 499 indicates the cal osc phase-locked-loop
probably can lock at 10.7 MHz, but cannot lock at the 9.9 and
11.5 MHz extremes. This may prevent the cal oscillator from adjusting
the 1 MHz or 30 kHz through 300 kHz bandwidths. This symptom
implies a failure in the oscillator, function block X. (See the A4 log
amp/Cal
oscillator schematic sheet 4 of 4.) The oscillator is unable
to tune the required frequency range with the -9 V to
+9
V control
voltage. Troubleshoot A4CR802 (
most probable cause), L801, C808,
C809, and U807.
500 AMPL 30K
Unable to adjust amplitude of 30 kHz resolution bandwidth.
501 AMPL .lM
Unable to adjust amplitude of 100 kHz resolution bandwidth.
7-32 General Troubleshooting