The EF80 internally screened pentode was a workhorse of the VHF TV receiver and was introduced in 1950. It was described by Mullard as: a high slope RF pentode.

The EF80 was much used for RF, intermediate frequency, and video amplification.

The 'bog standard' TV of the later 1950s was full of EF80s (or equivalents). In those days all British TVs were monochrome, 405-line standard, with a typical video IF of 33 MHz. The EF80 worked well at 40 MHz and also gave adequate performance at up to 100 MHz. The EF80 was superseded in the 1960s by the higher slope EF184.

The circuit designer is given maximum flexibility by having all electrodes brought to external pins. Many pentodes have g3, the suppressor grid, internally connected to the cathode.

The thin glass tube envelope is 20 mm diameter and excluding the B9A base pins, is 80 mm tall.

 
Pin Connections

B9A	1	2	3	4	5	6	7	8	9
	k	g1	k	h	h	s	a	g2	g3

 
Absolute Maximum Operating Conditions

Pentode	Va	Vs	Vg	mAa	mAs	ra	gm
	170	170	-2	10	2.5	0.4M	7.4

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 02 December 2007 {find valves by name}