One, Radiotron WD-12 tube, with the tubular shaped glass envelope. Metal base, glass tip at the top of the bulb, no chip in the tip. All internal structure is solid, full lime getter. The WD-12 tube is a UV based version of the WD-11 tube, which has a unique base. Tested on a Hickok TV-3 military tester that has been calibrated. Tube tests at 510 where pass/fail is 410 micromho, when tested as a #864 tube. My tester does not have a setting for the WD-11/WD-12 type tube. The #864 tube is a 1.1V filament triode of the 1930's and is the closest relative of the WD-12 tube.  It is actually a hard bar to pass for pre-1924 tubes. This tube was also tested in a period, one tube regenerative homebrew- with success.

Many other lots of tubes for sale this week.

Shipping is free within the continental US. Elsewhere- exact postage only, no packing fee.