Sounds like a C-1-K Thyratron.

73,
Dube K4DWW


"Art's Antique Radios" wrote in message
...
Going through a tube lot and found some tubes I cannot identify.

No markings on glass. Base is aluminum with ceramic. 4 pins. Number
printed boldly on base is CIK 1660090. Made in USA.

Anyone have any ideas? Possibly related to Ham gear.