The CV73 is a beam tetrode that is described for both audio use and television line output service. In the television role the valve can withstand a positive anode surge of 8,000 volts.

Given its number in the Common Valve listings it is a good guess that this valve was designed in the late 1930s to coincide with the start of 405 line broadcast television in 1938.

The anode is blackened to assist radiating away the heat generated. The ceramic insulators testify to the high voltages that appear on the anode in TV service.

The two grids are made of bright wire, probably Molybdenum, and aligned one behind the other to minimise screen grid current.

The classic envelope is 51 mm in diameter and, excluding the B7 base pins, is 116 mm tall.

 
Pin Connections

B7	1	2	3	4	5	6	7	tc
	-	g1	s	h	h	k	g2	a

 
Absolute Maximum Operating Conditions

Beam Tetrode	Vh	Ah	Va	Vs	Vg	mAa	mAs	gm	Pout	D
	4.0	2.0	250	250	-25	85	20	6.3	7.5	9%

Beam Tetrode	Vh	Ah	Va	Vs	mAa
	4.0	2.0	-	300	21.5

This exhibit was last updated on 02 December 2007