This exhibit is a late-1930s type TV4, tuning indicator. It has the then standard British 4.0 Volt heater, whereas the (otherwise similar) Type TV6 had the new American standard 6.3 Volt heater.

The TV4 was the first Mullard magic eye on the UK market. It was more compact than other available types (which made it popular with set designers) but early specimens had short lives. This was corrected by alterations to the internal design.

The picture clearly shows the construction of this valve with its end window and triode like electrode structure.

The end window envelope is 26 mm in diameter and the length is 72 mm. The base is Ct8.

 
Pin Connections

Ct8	1	2	3	4	5	6	7	8
	-	h	h	k	-	g1	t	a

 
Absolute Maximum Operating Conditions

CRT	Vh	Va	Vg	mAa
	6.3	250	5	0.13

This exhibit was last updated on 10 July 2005