Tube Coating

[CHRIS-F]

Hi All,

Just wondering if the coating on the back of tubes by the Anode is important? and what is it? I scraped it a little discharging the tube, but it was already pretty scraped to begin with, does it need to be replaced and if so what do you use?

Thanks,
Chris.

[buttersoft]

That shouldn't matter. Just make sure the area and the anode cap are clean. If you're still getting a little arcing or even corona after that, you can line the rim of the anode cap with some dielectric grease like spark plug grease.

[bobbyb13]

Certainly looks like primer.
Does anybody know if that was sprayed on first to get the dag layer to adhere better?

I have a few that are scratched like that one and pose no problem thus far.

[buttersoft]

It's not primer, it's only ever put on around the anode button, that i've seen. And only on some tubes. I'd always presumed it was an insulating coating designed to slow down the effects of the carbon buildup from the HV, which causes arcing.

[grantspain]

its called anti corona dope

[lilshawn]

its called anti corona dope

WHO YOU CALLIN A DOPE!?

 

[grantspain]

its called anti corona dope

WHO YOU CALLIN A DOPE!?

 

thats pretty good, unexpected 

[CHRIS-F]

Thanks Guys, I'll leave it if its not that important, I don't have any arcing, I just thought it may need doing to prevent any arcing.
I always thought it looked like the old red led paint