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My next project, dad's Philco 40-81
#9

Well here's a primer on a pretty simple way to make a b battery eliminator
http://antiqueradio.org/bsupply.htm. Mind you an isolation transformer would be wise, else you may create a shock hazard. Anything that supplies 60 to 90 volts will work OK.

For the filaments, you could use a couple of D Cells, or do a little more digging, and you may be able to get a small transformer that has both, say 110 volt and 6.3 volt secondaries, say salavaged from a piece of test equipment. Well then, you could then use a LM317 device to supply the correct filament voltage, the above quoted reference to supply the B+, and I think you would be done.

This has been summarized at least twice on this forum in more detail , but I just can't find it today. You know, senior moment. Somebody will remember and post.


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RE: My next project, dad's Philco 40-81 - by codefox1 - 01-22-2013, 03:51 PM



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