495RBW
IOK
496RBW
100
497RBW
100
498RBW
100
499
CAL
UNLK
500
AMPL30K
501
AMPL
.lM
502
AMPL
.3M
503
AMPL
1M
504AMPL30K
505
AMPL
.lM
506
AMPL
.3M
507
AMPL
IM
508
AMPL30K
509 AMPL
.lM
Unable to adjust 10 kHz Resolution Bandwidth. XTAL SWP GAIN
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.
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
V dc or -15 V dc, 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
i-9
V control
voltage. Troubleshoot A4CR802 (most probable cause),
L801, C808, C809, and
U807.
Unable to adjust amplitude of 30 kHz Resolution Bandwidth.
Unable to adjust amplitude of 100 kHz Resolution Bandwidth.
Unable to adjust amplitude of 300 kHz Resolution Bandwidth.
Unable to adjust amplitude of 1 MHz Resolution Bandwidth.
Unable to adjust amplitude of 30 kHz Resolution Bandwidth.
Unable to adjust amplitude of 100 kHz Resolution Bandwidth.
Unable to adjust amplitude of 300 kHz Resolution Bandwidth.
Unable to adjust amplitude of 1 MHz Resolution Bandwidth.
Unable to adjust amplitude of 30
kHz Resolution Bandwidth.
Insufficient gain during LC BW Cal.
Unable to adjust amplitude of 100
kHz Resolution Bandwidth.
Insufficient gain during LC BW Cal.
6-26 General Troubleshooting