roland fet

[jhaible]

> Not so much of colour but the letter is written on the side of the can.
> The parameter that determines grade is the Vp, or pinch off voltage. In
> a FET follower circuit, this will affect offset of the output in
> comparison to the input voltage. GR is the worst, highest. O is the
> lowest that you can get hold of, but there is one lower. Y is the
> standard one it seems. There is an overlap between the grades. I have
> tested some O types to be worse than Y types.

This is interesting. I knew they were sorted in threshold groups, but
not which one was which letter.

BTW, "worse" should be relative. Higher threshold voltage, larger
current. Just started breadboarding 14 envelope followers with FETs
as VC switches, and wondered if the "A" types (BF245) have enough
current for this application.

JH.