replacement tubes for Quickie

[sameerverma]

I have a newly built Quickie 1.1

While the tubes that came in the box (Tungsram) are fine, what kind of tubes should I look for to replace these? Only 3S4?

--
Sameer

[mcandmar]

Or DL92 which is the European equivalent, and the MIL spec tubes are labelled VT-174 and CV820.

With a simple change of the heater circuit wiring you can also use 1S4/DL91 tubes.  Identical tubes other then the heater voltage is 1.4volts vs 2.8volts.