DE5B Marconi metal base – B3 balloon British Thompson Houston – Marconi DE6 Pip – Osram DE8HF – B6 British Thompson Houston

Description

Valves in this section are:

Marconi DE5B Metal Base Top Pip. This valve has an amplification factor of 25 and an impedance of 25 Kohm. It is a directly heated triode of the late 1920s. It is an excellent amplifying valve in radio and audio sets.

BBC BTH British Thompson Houston metal base Top Pip B3 The B3 is a dull emitter of 1923 and has thoriated tungsten filament which is straight wire

Marconi balloon pip DE6 pip top. This valve was introduced in 1926 by the MO-V with filament rating at 2Volts. Widely used on many 1920s sets.

Osram DE8HF Top Pip This valve saw the light in 1925 with a 6 Volts heater and was made for R.F. Amplifiers

BTH B6 Top Pip The B6 is similar to the B3 and B4 being a dull emitter