"Jim" wrote in message
...
i need a variable for a receiving loop antenna. does anyone know how to
determine the area of plates for a given value of cap? for example i
need 365 pf. two half circle plates would be handy, separated by a piece
of plastic or card stock. what surface area for each plate would
approximate that value? does two stator plates with one rotor between
them increase the value if compared to one plate each?


Here is the "How to Build an Air Variable Capacitor" article you are looking
for:
http://www.eham.net/articles/5217

w9gb