Mystery Cap

[TIMBO]

Hi guys, this may not be a mystery to some of you but it a new one for me.
My recent buys have had a small value cap across the plate and screen supply on the power tubes.

Can anyone enlighten me on their purpose. Thanks

[kagliostro]

Ciao TIMBO

this is your schematic



and this is the Selmer Stadium TV19/T schematic



I think they are the same concerning those caps

explanation of the function of the caps here

http://el34world.com/Forum/index.php?topic=18467.msg188642#msg188642

Ciao

Franco

[trobbins]

It can also function as anode over-voltage protection - that position needs a lower voltage rating cap, than if it was placed from plate to ground, or plate-plate.

The Selmer TV19 has anode stoppers, so the anode caps would further tame any high frequency instability that may have occurred.