Re: 577 AC collector supply not reading zero on display


Reading the manual I notice the following for the collector supply

120 Volts is fed to T101 autotransformer (Variable collector)

K125 turns T101 on or off

The wiper of T101 goes to what appears to be a filter L101 R101 and C101, and then it goes to the primary of T102

From T102 it appears this is where I get 6.5 25 100 400 and 1600V from for the collector

For 6.5 to 100V rectifier CR107 is used and above that CR103-106 is used

Since different rectifiers are used at higher volts I decided to test my problem at higher voltages, the problem appears to get much worse

At 1600V 8kOhms 5V Division 0 collector volts the line is 4 divisions across which should be 20V, not good

The collector supply appears somewhat simple if i look at certain sections of it. I feel like I simply have a T101 autotransformer issue. The wiper is making contact to the very edge but yet it acts like i have it turned up partially. Maybe a issue with T101 or maybe K125 or perhaps C101 is bad? I feel this problem is occurring at the beginning of the collector supply stage.

Join to automatically receive all group messages.