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> CK650 650 subminiature mystery pentode tube nos
CK650 650 subminiature mystery pentode tube nos
You get one Raytheon CK650 subminiature pentode tube in a white box. These tubes are New Old Stock, marked and branded. This tube is still a mystery here at TTW, I have not found any specs anywhere online yet. I think sometime in the early fifties Raytheon renumbered some of there tubes, Moving the CK5?? to the four digit series. Most of the online datasheets are for the tubes after they were renumbered and it can be difficult to find data on the old numbers. This tube is a large envelope tube like the 5902 Beam Pentode. It has the same construction as the 5902 and the same base pinout, but the grid wires are more closely spaces so I know it is not a 5902. What is it??? If you have an idea I would love some info on it.
I received this info from Paul Wiggins.
The CK-650 is, apparently, a selected version of the 5639,
a tube that I believe harbors enormous potential for audio
amplification. This guy shares the plate, cathode, and
heater electrodes with the 5902, as you observed; only in
the grids' pitching do the tubes differ. The 5639 is described as a
specifications, closely resembles the 12BY7A of Tek
and H-K fame. However, the 5639 showcase a low-voltage
capability, and a BEEFY mechanical construction that
the larger bottle cannot remotely rival. I have examined
other military data that attest to the outstanding item-to-item
consistency and to the lengthy service lifespan of this
