The PCF80 is from the era of VHF television in the 1950s and early 1960s. This valve is a triode pentode, with separate cathode connections. The PCF80 was designed to function as a mixer and oscillator in the tuner at between 50 and 190 MHz.

Seen from the side the relative sizes of the two electrode structures become clear. The triode, on the right, is much smaller than the pentode section.

See also PCC84 for the corresponding pre-amplifier valve for Band III television tuners from the mid 1950s.

The thin glass tube envelope is 20 mm in diameter and, excluding the B9A base pins, is 47 mm tall.

References: Datasheet & ¹⁰⁴⁰ Type PCF80 was first introduced^¶ in 1953.

 
Pin Connections

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

 
Absolute Maximum Operating Conditions^¶

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	9	0.3	170	170	-5.5	5.2	1.5	0.87M	2.1

Triode	Va	Vg	mAa
	100	-2	14

Thanks to Frank Philipse for supplying the above PDF datasheet

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