Quote:
Originally Posted by dieseljeep
The B+ source is relatively easy to build, the 1.5 volt, high current supply is a little more difficult. The schematic shows that the filaments are wired in parallel.
BTW, the 3S4 is only rated for around 67.5 volts, plate and screen, so I would try to stay around those parameters.
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I was planning on building this:
http://www.antiqueradio.org/art/Powe...ySchematic.jpg
My filament draw is only .2 amps; and quite frankly; I'd those off batteries if I had to. But that has a 300ma 1.5V filament supply and 20ma b+ supply; the b+ draw is about 9ma. I think that transformer is only around $11; and the parts are small enough I could build where the batteries would reside.