The type S217, is a low cost vari-mu RF pentode imported during the late 1930s as a replacement valve in 2V battery radios. Triotron was an Austrian firm and was at this time probably partly owned by Philips.

The performance figures are good and would enable the S217 to replace any of several BVA types with reasonable efficiency. However, all such valves were obsolescent by the late 1930s.

It has the gold external metalisation that was so popular at the in the 1930s.

The classic envelope is 42 mm in diameter and, excluding the B7 base pins, is 110 mm tall.

 
Absolute Maximum Operating Conditions

Pentode	Vh	Ah	Va	Vs	Vg	mAa	mAs	gm	μ
	2.0	0.18	150	150	-0.5	3.0	1	1.7	900

This exhibit was last updated on 18 July 2007