temp coefficient factor for capacitors

[W9BHI]

I'm looking at some doorknob capacitors to use as a plate blocking cap in a tank circuit.
My choices are N750 or N3300.
Wich are more suited for this application?

Don W9BHI

[KA2DZT]

Probably neither.  Why are you trying to use a negative temp coeff. cap??

Fred

[W9BHI]

That's all that is available in 500pf 7.5KV OR 15KV.
Don W9BHI

[KA2DZT]

Good reason,  I guess I would use the N750 at the highest voltage rating.  Lets see what others may think about this.  I'm sure we'll get more input on the subject.

Fred

[W9BHI]

I figure that if it was a padder and changed value with temperature, that might be an issue.
Just being used as a bypass at the bottom of the plate choke or
as a plate blocking cap in a PI output, a slight drift in value may not affect the tuning.
Maybe?
Don W9BHI

[N2DTS]

I would not think it would matter under most uses.
Caps are not stable with temp unless they are npo, so regular caps change, just in the other (positive) direction.

In really high Q tuned circuits, whatever was used would be best, since it was designed for that, but I cant think of anything that fits that description at HF except vfo's or maybe some sort of high Q  filter.