HK-357

The HK-357 is a 150 watt dissipation pentode based on the HK-354 filament and anode structure. This was produced by Heintz & Kaufman starting in early 1934. The example shown has the additional marking Manufacturef for Westinghouse Electric MFG Co. Chicopee Falls, Mass. There is little evidence that this tube was produced in any quantity. It was one of the first gridded tube made by H&K, but within 2 years was not found in any of their literature. This example has a thin ceramic insulator holding the geometry of the grids. Other examples had a different structure. H&K staff pushed the idea of using the 357 as an oscillator/driver for higher powered amplifiers. RADIO in June 1934 had an article showing the 357 used in this way to drive a pair of HK-354 triodes. That transmitter was built by Bill Eitel, W6UF. This article is the only source of tube parameters we have found. The supressor grid is directly connected to the base shield so the shield needed to be jumpered to one side of the filament.

Length = 8.50" Diameter = 3.12"
Max voltage = 2000
Max current = 180 ma
Fil voltage = 5
Fil current = 10 amps         GOTO INDEX