Barrett wrote:
Some one sent me an email and said these will do the job. Ceramic capacitor
disk 10KV/1000pF. Do you think these would work?

Depends on the dielectric material. There are some 10kV 1000pF caps out
there that have a fair amount of loss at RF and a fairly big temperature
coefficient, so as they get hot, the tuning will change.


What you want to know is how much current is flowing through the
capacitor. Then you can look up the capacitor ratings and figure out if
it will explode, melt, or work just fine.

Think about what that trap is doing, too. At frequencies above the
resonant frequency, any current will be flowing through the capacitor
(because its reactance is smaller, while the inductor's reactance is
larger), but, the current might actually be pretty small. Say you have
a 10-20 meter antenna with a trap. On 10m, you want the trap to "turn
off" the 20 meter extension, so it's roughly at the "end" of the 10m
dipole. That's where the current is lowest.

At frequencies below the resonant frequency, the capacitor's reactance
is higher, and more of the current flows through the inductor.