Another Really Rugged Coil
I just completed this 20 meter coil which will join my RRC (Really Rugged Coils) antenna system that continues to expand as seen in the lower insert photo.
I build the coliform from 3 pieces of Delrin that I turn to shape in the lathe, that being the main Delrin coliform tube section with the two Delrin endcaps.
The coilform is wound with 14 gauge wire with 8 tpi spacing that I cut in the lathe.
To build the mounting hardware at either end of these coils, I initially start with a UHF to BNC rf connector.
I remove the BNC end and then with the remaining UHF end, I make the modifications required.
The upper insert photo gives you a look at how I replace the center insulators of the UHF rf connector at either end of the coil with solid brass machined inserts to increase the ruggedness of the coil.
There is no need for an insulator, as the screw-threads at either end of the coil are conductive, and all the center pins in the PL-259's are utilized for are alignment when changing out coils.
My RRC antenna system was designed to be driven with 500 watts out regardless of what band coil is mounted in place.
The same 60 inch whip is used with all of the coils
Also my coils are sealed against any and all weather that may occur with temperatures ranging from -40C to +40C
Of course it goes without saying that the coils may be changed out with one's hands, no tools required.
Click on the photo for a closer look....
Another view of my RRC antenna system.....