45 tube types

Are there variations on the 45 tube, numbered in some other way, that I'm simply not seeing?

I'm pretty certain the answer is "no."

You might want to take out a subscription to Antique Radio Classified, which would allow you to place a free want ad each month. 45's were used in a number of high-end antique radios ca. 1932.

Also, some of these places might be worth contacting.

Regards,
-- Al

They are on Ebay fairly often... typically you can get a pair of National's or Philco's new for around $90 a pair. I can't recommend any seller in particular.

Of course you can always go to Emision Labs.