[Milsurplus] JAN Dual Tetrodes

[gl4d21a at juno.com]

Hollow state discussion.  Silicon fanatics need not read.  

In the beginning there were 829Bs and 832As and some RK somethings or other, then Amperex upped the ante with the 5894 and it's cousins.  And, somewhere in there, Amperex also introduced the 6252, a little bottle which was good to 500 MHZ, but needed cross neutralization.  Badly needed it.  See ARRL handbooks of the '50s.  Around 1955, GE Mobile Radio went to Amperex and said: "If you can get that bottle self neutralized in the 450-470 MHz band, we'll buy a whole bunch.  Oh, and by the way, it also needs to work from 405 to 420, too."  And, so, the 6907 was born.  And GE Progress Line 450 used two 6907's in every transmitter.  The higher power version of the bottle never materialized, even though all transmitter chassis had two sets of holes for the plate circuitry of the final amplifier, one for the 6907, and a second, slightly further away for a taller, more powerful tube.  No, 5894s won't fit, darn it.

What does this have to do with milsurplus?  Well, I think I asked before, with inconclusive results.  What government equipment used 6907s?  In clearing out the estate of an SK MARS member, I found several 6907s in typical military disintegrating cardboard boxes, and with JAN nomenclature stencilled on the glass.  I have never known of any other application for that bottle than GE 2-way, and am real curious about why JAN versions would be produced.  I suppose it would be a natural in 225 - 400 MHz military aircraft comms equipment, but I am not familiar with enough different models to know of an actual use.  What am I missing?

Experts?

73,
George
W5VPQ

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