Tag: Philips Electrolytic Capacitors
Racal 9478: Widespread Electrolytic Capacitor Failure
25th May
The Racal Dana Model 9478 Frequency Distribution System has an internal precision, oven-controlled crystal oscillator, or it can be phase locked to an external signal derived from a GPSDO or other master oscillator. The system will automatically lock to an external signal above 100 mV, and with a standard frequency of 1, 5 or 10 MHz. “In Lock” indication is provided.
I recently repaired two Racal 9478 units. What I found was widespread electrolytic capacitor failure such as I had never encountered before. A summary of the issues found in both units follows:
Virtually all electrolytic capacitors in both units (nearly 90 in all) had failed, showing either very low capacitance and/or very high ESR. Interestingly enough none showed short circuit failure.All the failed electrolytic capacitors were made by Philips in late 1980’s The -15v regulator was originally bolted … Read More »