495 RBW IOK

Unable to adjust 10 kHz Resolution Bandwidth. XTAL SWP GAIN

496 RBW 100

Unable to adjust 100 Hz Resolution Bandwidth. Inadequate Q,

497 RBW 100

Unable to adjust 100 Hz Resolution Bandwidth. Alignment problem.

498 RBW 100

Unable to adjust 100 Hz Resolution Bandwidth. Gain.

499 CAL UNLK

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.

500 AMPL 30K

Unable to adjust amplitude of 30 kHz Resolution Bandwidth.

501 AMPL . l M

Unable to adjust amplitude of 100 kHz Resolution Bandwidth.

502 AMPL .3M

Unable to adjust amplitude of 300 kHz Resolution Bandwidth.

503 AMPL 1M

Unable to adjust amplitude of 1 MHz Resolution Bandwidth.

504 AMPL 30K

Unable to adjust amplitude of 30 kHz Resolution Bandwidth.

505 AMPL .lM

Unable to adjust amplitude of 100 kHz Resolution Bandwidth.

506 AMPL .3M

Unable to adjust amplitude of 300 kHz Resolution Bandwidth.

5 0 7 AMPL IM

Unable to adjust amplitude of 1 MHz Resolution Bandwidth.

508 AMPL 30K

Unable to adjust amplitude of 30 kHz Resolution Bandwidth.

 

Insufficient gain during LC BW Cal.

509 AMPL .lM

Unable to adjust amplitude of 100 kHz Resolution Bandwidth.

 

Insufficient gain during LC BW Cal.

6-26 General Troubleshooting