The HK-254 is a 100 watt dissipation triode made by Heintz and Kaufman with a mu of 25 and a maximum frequency of 175 MHz for full ratings. Early versions had an open anode and no shield around the press as in the first example. Similar tubes were also made by Lewis and Kaufman (LK-254), Cascade Research and Eimac (254W).

Length = 7.12" Diameter = 2.62"
Max voltage = 3000
Max current = 225 ma
Fil voltage = 5
Fil current = 7.5 amps         GOTO INDEX