HP 8562E Service Manual page 251

Spectrum analyzer
Table of Contents

Advertisement

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
500 AMPL 30K
501 AMPL .lM
7-32 General Troubleshooting
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
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.
intermittent
An
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
to tune the required frequency range with the -9 V to +9 V control
voltage. Troubleshoot A4CR802 (most probable cause), L801, C808,
Unable to adjust amplitude of 30 kHz resolution bandwidth.
Unable to adjust amplitude of 100 kHz resolution bandwidth.

Advertisement

Table of Contents
loading

Table of Contents