[Amps] Fwd: 8877 Grid Connection DC or Not

[Bill Turner]

------------ ORIGINAL MESSAGE ------------(may be snipped)

On Tue, 29 Nov 2016 06:37:46 -0500, gudguyham wrote:

>Don't forget a grid trip overload protection.

REPLY:

The 8877 has a grid dissipation rating of 25 watts. The actual
dissipation when driven to 1500 watts is about 2.5 watts. Unless you
are unusually careless, you don't need a grid protection circuit. 

Remember the driving power of 40-60 watts in grounded grid is mostly
"fed through" to the output. There are tubes with extremely fragile
grids but the 8877 is not one of them. 

A commercially built amp is different however. Since the maker has no
control over who is going to operate it, a grid protection circuit is
probably a good idea, but in a homebrew amp where the builder and
operator knows what he is doing, it is overkill IMO. 

73, Bill W6WRT