This magnificent green metalised valve from Mazda is marked as FO141 but is in fact an FC141.

This low consumption battery heptode was designed for use as a frequency changer. Such valves were very quickly displaced by B7G based valves and were, therefore, never made in large quantities.

Our exhibit is unused, and the typical fate of these valves, and the sets, was that they were discarded when the special batteries became hard to obtain.

The classic envelope is 31 mm in diameter and, excluding the MO base pins, is 80 mm tall.

 
Pin Connections

MO	1	2	3	4	5	6	7	8	tc
	f	-	a	g2	g1	m	g3,g5	f	g4

 
Absolute Maximum Operating Conditions

Heptode	Vh	Ah	Va	Vs	Vg	mAa	mAs	ra	gm
	1.4	0.05	82	45	0	0.55	0.6	0.6M	0.25

Thanks to Frank Philipse for supplying the above datasheet

This exhibit was last updated on 22 February 2009 {find valves by name}