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Power Xformer Question

11/16/1999 11:32 AM
BC	Power Xformer Question Greetings, I have a Princeton Reverb that has been giving me fits and I need a little help with understanding Power Transformers. When I first started to work on it I found that the plates of the 6v6's were seeing 440vdc @ 28 ma…a bit too high for comfort and reliability. Upon examining the PT I found that it is a replacement with multi-taps for the primary windings. One of the wires is solid black, which I assume is the common tap, and the other six are multi-colored with resistance reading ranging from 4.8 - 24 ohms to the black wire. I found one of the wires with slightly higher resistance than the one that was hooked up (giving me 440vdc at the plates) and hooked that one up to see what I'd get. Well, the voltage at the plates dropped to 405vdc @ 29ma….much better. The question I have is does the black wire (common tap?) need to be used? If I can find a pair of the multi-colored wires that will give me a resistance on the primary that is between the two I tried , can I use them safely? I would like to get around 410-420vdc on the plates. Thanks, Bob Cassen

11/16/1999 11:32 AM

Power Xformer Question

Greetings,
I have a Princeton Reverb that has been giving me fits and I need a little help with understanding Power Transformers. When I first started to work on it I found that the plates of the 6v6's were seeing 440vdc @ 28 ma…a bit too high for comfort and reliability. Upon examining the PT I found that it is a replacement with multi-taps for the primary windings. One of the wires is solid black, which I assume is the common tap, and the other six are multi-colored with resistance reading ranging from 4.8 - 24 ohms to the black wire. I found one of the wires with slightly higher resistance than the one that was hooked up (giving me 440vdc at the plates) and hooked that one up to see what I'd get. Well, the voltage at the plates dropped to 405vdc @ 29ma….much better.
The question I have is does the black wire (common tap?) need to be used? If I can find a pair of the multi-colored wires that will give me a resistance on the primary that is between the two I tried , can I use them safely? I would like to get around 410-420vdc on the plates.
Thanks,
Bob Cassen

Replies:

R.G. While there is no way of knowing ex... -- 11/16/1999 1:26 PM