E8257D/67D, E8663D PSG Signal Generators Service Guide
Troubleshooting
Troubleshooting Assembly–Level Problems
1-54
d. On the A37 Upconverter, disconnect J5 and connect a spectrum analyzer to the cable coming from the
A27 40 GHz Doubler. This is the LO signal to the A37 Upconverter.
e. For RF signals >20 GHz to 28.5 GHz, the IF signal is mixed with the LO to produce the downconverted RF
signal. The LO signal will range in frequency from 26.667 GHz to 38 GHz and will be four times the IF
frequency. The amplitude of the LO signal should be >5 dBm.
• If the signal is bad, troubleshoot the A35 RF path.
• If the signal is good, reconnect A37–J5 and replace the A37 Upconverter.
f. For RF signals >28.5 GHz, the IF signal frequency is mixed with the LO to produce the upconverted RF signal.
The IF signal will range in frequency from 5.73 GHz to 8.82 GHz. The LO signal will range in frequency from
22.8 GHz to 38.2 GHz and will be four times the IF frequency. Repeat steps a through e, but with an RF signal
>28.5 GHz.
Self–Tests 13xx: A11 Analog/Pulse Modulation Generator Self–Test Errors
Before proceeding to the reported self–test error code, check the following voltages. If any of these voltages are out of
specification troubleshoot the supply problem first.
Supply Voltage
(Vdc)
Connector Pins Minimum Value
(Vdc)
Maximum Value
(Vdc)
Origin
+15 P132–28 +14.55 +15.45 Main Supply
–15 P132–3 –14.55 –15.45 Main Supply
+5.2 P132–2, 27 +5.04 +5.37 Main Supply
–5.2 P132–1, 26 –5.3 –5.1 YIG Driver
+5.2 Digital high P131–64, 65, 129, 130 +5.04 +5.36 Main Supply
+3.4 Digital Low P131–60, 61, 62, 63,
125, 126, 127, 128
+3.29 +3.5 Main Supply
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