The HF-300 is a 200 watt dissipation triode with a mu of 23 and a maximum frequency for full ratings of 40 MHz developed by Amperex. The early tubes from the late 1930s had a brass "brimmed hat" top cap as in the second example. The third example was made by General Electronics and the fourth by National Union.

Length = 10.25" Diameter = 4.00"
Max voltage = 3000
Max current = 275 ma
Fil voltage = 11 to 12
Fil current = 4 amps         GOTO INDEX