The L77 triode was specified as both an amplifier and an RF power valve. In the latter role it would deliver 5.5 Watts. With a very small envelope volume, this would make it ideal for hand portable equipment. In larger apparatus it could deliver enough drive power for much larger PA's.

The anode is a blackened flat sided box with ribs pressed into the sheet metal to give extra mechanical stiffness.

The face view. the side flanges aid radiation and provide a flat area for the fixing notches.

The thin glass tube envelope is 18 mm in diameter and has an overall length, excluding the B7G base pins, of 48 mm.

 
Pin Connections

B7G	1	2	3	4	5	6	7
	a	k	h	h	a	g1	k

 
Absolute Maximum Operating Conditions

Triode	Vh	Ah	Va	mAa	gm	Pdriv	Pout	Pdiss	freq	f.max
	6.3	0.15	250	10.5	2.2	0.35W	5.5W	5W	70	150

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 03 July 2009