If you run tube filiments off DC the filiment life will deteriorate due to filimemt streatching. Halacrafters made a radio that ran on 67.5 VDC and 110 VAC.
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if you are really in to that ancient tech , www.lindsaybks.com has a lot of manuals . old and new on th' suject , including one that tells you how to make yer own and design them for a specific purpose !
Here's a tube tutorial that looks pretty good for a start. Then google "vacuum tube tutorial" if you want more. Lot's of websites on tube radios and amplifiers available. And lots of tubes still around. Good luck.