The DE2HF is a dull emitter triode dating from 1925. It was designed for RF amplification. The valves from M-OV of this period used carbonized thoriated tungsten filaments. The carbonizing reduced the effects of any residual gasses in poisoning the thoriated filament.

See also DE2LF.

The BBC logo is present on this valve illustrating the fact that this valve is an original 1920s valve and not a later replacement.

The balloon envelope is 32 mm in diameter and, excluding the B4 base pins, is 73 mm tall.

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	Vg	mAa
	2.0	0.12	45	-	0.5

This exhibit was last updated on 02 December 2007