Antenna wire series capacitor

Thread Starter


Joined Aug 31, 2014
I'm building a lightning detector from ( On the page the author describes using a series capacitor with the antenna wiring. Can anyone explain what this would be for? Also - an antenna for a receiver like this - I was going to use some copper wire I have around here, I assume that would be OK? Thanks in advance! Lee


Joined Aug 21, 2008
If your wire antenna is insulated from earth and the circuitry of the detector besides the input you don't need the capacitor. If you have strong low frequency electrical noise (nearby power lines) then a low value series capacitor at the receiver input might help reject the interference.

sparky 1

Joined Nov 3, 2018
That is a good question.
Charles lives where lightning storms are intense. The design might be showing a responsible design or just works out good for his situation.
Years ago in radio antenna systems, lightning arrestors were placed in that arrangement. An arrestor used two plates having a gap, It is conceivable with that type large capacitor that it might be an arrestor. It is difficult to determine what his intention was to deviate. It might eliminate ground loops or used with artificial ground.

I am not certain why, I can show an example of old lightning arrestors.
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