Maxwell House RF Choke

A new, highly effective RF-Choke!


Recent ARRL Lab tests determined coffeen to be an excellent impedance to Common Mode Current.

When building this choke, do not use Cafeen-Free coffee.


It was also found that 100% Arabian Coffee produced significantly more Common Mode Impecance (CMI) than South American Coffee.  


To determine the number of turns of coax, use the following formula:

This new design is especially recommended for Beverage Antennas.

(Your mileage may vary.)