The design of the Cossor 203THA triode hexode mixer dates from 1939. The 203THA is electrically identical to the 4-THA apart from the 300 mA heater. Thus this mixer was designed for series heater chain receivers.

As well as the printed paper label the other side of the envelope has the type designation printed onto the external metallisation.

The Classic envelope is 45 mm in diameter and, excluding the B7 base pins, is 110 mm tall.

 
Pin Connections

B7	1	2	3	4	5	6	7	tc
	a(t)	gt,g3	g2,g4	h	h	m,k	a	g1

 
Absolute Maximum Operating Conditions

Hexode	Vh	Ah	Va	Vs	Vg	mAa	mAs	gm
	20.0	0.3	250	100	-2	3.5	5.5	0.85

Triode	Va	mAa
	100	1.5

This exhibit was last updated on 02 December 2007