Posted by Damir [ 213.202.96.212 ] on November 20, 2005 at 05:10:03:

In Reply to: Worth my while? posted by Jeff on November 19, 2005 at 20:20:04:

Good price, but 42VA and 55mA DC (with cap input) are not much, and 385-390V DC specification is a little strange to me (no AC secondary voltage given) - that probably means that you can expect this voltage/current after rectification? We need to know AC secondary voltage (probably about 300V AC if 390V DC is specified). You`d need 250-300V DC "through" the tube, and 45-65V "through" cathode resistor tipically for 2A3, and about 10-15V voltage drop through the OPT primary winding resistance. It can work like SS diodes "bridge" rectifier, with small, "tuning" input cap to get voltage you need, then LC filter. With full specs (secondary AC voltage, primary and secondary resistances), you can model the PS with "Duncan PSU II" program.
For the other, "off the shelf parts" you`d need two output transformers, say Hammond 125ESE (~$36 each), two chokes, tubes and other mechanical and electrical parts.
If you choose to build this project and have some additional questions, try "Group Build" forum.

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