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Marconi 156 power transformer change
2/26/2003 8:25:42 PMJ-F
Hi! The original tranformer is bad (5v, 6.3v, 235v*2). 5V winding is open. Original plate voltage is 2*235V = 470V. Can I change it for another that has 2*350V = 700V plate voltage? Exact replacement is hard to find. And I have this one that fit in hole.

Thanks for your help again!
J-F

2/26/2003 11:32:21 PMNorm Leal
Hi J-F

Unlikely the 5 volt winding is open. It's made from heavy wire. Could lead wires to the winding be open?

If you can't get 5 volts, try adding some additional turns around the core. 5 volts will probably only take 15 turns or so..

Original high voltage was 235 each side of CT ,350 will be too high. You could use a dropping resistor but it needs to be wire wound and will be very warm.

Norm

:Hi! The original tranformer is bad (5v, 6.3v, 235v*2). 5V winding is open. Original plate voltage is 2*235V = 470V. Can I change it for another that has 2*350V = 700V plate voltage? Exact replacement is hard to find. And I have this one that fit in hole.
:
:Thanks for your help again!
:J-F



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