The 5F23A is a 400 watt dissipation tetrode made by Toshiba. The usable frequency for maximum ratings is 75 MHz. This is similar to the 4-400B except for different plate ratings and maximum frequency. The 5F23 is the same tube but has the metal skirt like a 4-400A.

Length = 5.80" Diameter = 3.56"
Max voltage = 4500
Max current = 310 ma
Fil voltage = 5
Fil current = 14.0 amps         GOTO INDEX