Topband: Homebrew capacitors

[Richard Karlquist]

> On 09/29/2013 07:42 PM, Jim GM wrote:
>> Could have saved more money with a Piece of RF-9913 or RG8 coax cable 
>> about
>> 25pF per foot plenty voltage rating.
>> 
>> 
>> Only thing can some one please help me on this, do I connect the 
>> center
>> conductor on one end of the cable and use the shield on the other end? 
>> Or
>> just use the  center conductor and shield on one end, while the other 
>> end
>> are floating not used and not tied together?

Neither.  Instead fold the coax and connect to both ends in parallel.
IOW, connect the center conductors in parallel and the shields in 
parallel.
This will greatly reduce the loss due to the resistance of the 
conductors.
Constructing a capacitor out of coax is a suboptimal topology, but 
folding it
and connecting the ends in parallel at least mitigates the loss.

Rick N6RK