Installation guide

Troubleshooting
Troubleshooting Assembly Level Problems
1-38
409 ALC Modulation Test
• Replace the A13 Output.
410 Burst Modulation Test
• Replace the A13 Output.
411 ALC Detector Test
• Replace the A13 Output.
412 Het Band Test
• Measure the 1 GHz signal from the A18 Reference.
a. With the power off, remove the A13 Output and insert a ribbon cable extender into J11 of the A19
Daughterboard.
b. Power on the signal generator and tune to a CW frequency of 200 MHz.
c. Using a spectrum analyzer, probe pin 19 of the ribbon cable extender
1
for a 1 GHz signal with
an amplitude > -20 dBm:
— If the signal is present, replace the A13 Output.
(Refer to “A13 Output” on page 2-32.)
— If the signal is not present, power down the signal generator and remove the A18 Reference.
(Refer to “A18 Reference” on page 2-42.)
d. Using a DVM, ohm between J11-19 and J51-19:
— If the path is open, replace the A19 Daughterboard.
(Refer to “A19 Daughterboard” on page 2-44.)
— If the path is good (zero ohms), refer to the A18 Reference troubleshooting for the 1 GHz VCO.
413 Bulk R DAC Test
• Replace the A13 Output.
414 Log Offset Test
• Replace the A13 Output.
1. The ribbon cable extender needs to be assembled by the user. It consists of two connector plugs
(part number 1252-1010) and approximately eight inches of ribbon cable (part number 8120-2226).
The ribbon cable contains 26 wires; six of these wires need to be stripped off before being connected
to the plugs.