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Nothing Major
UPDATE, SEPTEMBER 13, 2018
Nothing Major.
From Mike: I hooked up a variac to the chassis a couple of days ago and started it at 25 volts. Then about 5 minutes later I set it to 50 volts and watched the power supply tubes start conducting. They are a set of 5U4’s and there are 3 of them for the different voltages that form the power supply. The purpose of this exercise is to determine the exact running voltages that were originally designed in to the system using the 5U4 vacuum tubes. I got the voltage up to the nominal 120 VAC after many small steps and I got smoke from one of the resistors in the power supply. NOT a surprise at all. The reason for the smoke is an “open” capacitor in the power supply section of the circuitry. As it turns out, Westinghouse made this chassis such that the “power supply” is not limited to the chassis below in the cabinet. That chassis is only the first stages of the supply, which is rectification and “preliminary” filtering of the pulsating DC that is created from the rectifier tubes. There are a number of places in the chassis where they placed “redundancy” filtering to make sure that he DC was always pure everywhere in the system. I will be doing a lot of re-capping as a result of diagnostics in an effort to methodically bring this thing back to life. Once I determine what the “actual” operating voltages are, I will be installing solid state rectifiers in place of the 5U4’s and then applying resistance values in the system to reproduce the proper and “original” DC supply values. This placing of resistance values is necessary due to the fact that the solid state rectifiers are much more efficient than the original 5U4’s that are very inefficient by comparison.
I just placed a very large order for capacitors so I can press on to the next phases.
Regards, Mike.
Author: No photos on this one.
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