[GreenKeys] Radio valve/tube CG 502A

[Jones, Douglas W]

On Mar 22, 2017, at 11:48 AM, E. Groenenberg wrote:

> I have found 10 pieces of radio valves/tubes, metal can with
> the print 'JAN CG 502A' on them

Google finds this document title, published Aug. 5, 1955 and currently listed as obsolete with no superseding document:

MIL-E-1/909 › Electron Tube, Transmitting, Thyratron, Tetrode, Gas JAN-502A

Type 502A tubes appear to be widely available at $5 and up.  I didn't find a spec sheet, though.