any version of the type 27 tubes are very common and were used mostly in
1928-1930 era AC radios. They can be used as audio drivers, which is what
they were in radios. However, the audio community doesnt think much of
them, at least today.
Used, tested ones sell for $5 or less each, usually. Also common from that
era is the UY-224 (24A).
Mark Oppat
Antique Audio


"Nc183d" wrote in message
...
Hi All,
I have a few N.O.S. RCA UY-227 tubes. Is there any use for these anymore
or am
I holding onto them for no good reason? Are they worth anything at all? I
think
that several years ago, I heard them referred to as "heater" tubes. I
didn't
know that anything got hotter than a good old metal 6L6 tube....
rgds,
Mark S.