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.
Of course you can always go to Emision Labs.
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Following my earlier post, I received an informative communication from member Audiofeil, who indicated the possibility that variants of the 45 might have been produced under the designations 245 and/or 345, with identical specs and differing only in the shape of the glass (these being what is referred to as globe shaped). I then looked in the book "Tube Lore," written by Ludwell Sibley, who is a renowned expert on early tubes. It lists the 45 as AKA (also known as) the following types: SE-3921 38045 UX-245 VT-45 FR-304 CV596 The book also indicates that 300-series counterparts of many 2-digit tube types were issued under the Cunningham label, so a CX-345 is also a possibility. There was also a 45A, which the book indicates was similar to the 45 except uprated from 250 volts to 325 volts, and from 1.6 watts to 3 watts. Hope that helps, and my thanks to Bill Feil. Regards, -- Al |
Sounds to me like you are in luck! Here is a datasheet on the CX-345, which as you'll see speaks of it as if it were a 45. I compared the spec numbers with those of a 45 that appear in a reprint of an early tube manual I have. There are a few differences, but they are EXTREMELY minor (examples: mutual conductance 2100 vs. 2050; plate resistance 1670 vs. 1700; g-p capacitance 8pf vs. 7pf). As an antique radio collector, I have never encountered any incompatibilities between 2-digit tubes and their 200 and 300 series counterparts. Finally, the Sibley book states that the "only important exception" to the Cunningham numbers paralleling standard industry and RCA practice was the type 373. Good luck! -- Al |
- 14 posts total