PAC-12 Antenna
My primary HF antenna for SOTA is a homebrew version of the Pac-12 antenna designed by KA5DVS. I built it according to the instructions on the NJQRP Club website with the following changes (see images at the bottom):
Buddipole Whip:
I used a featherlite whip from Buddipole instead of the Radio Shack Whip. This whip has ¼-20 threads which means that there is no need for any sort of adapter. At only $6 each, they are well worth it.
Coupling Nuts
At the ends of the loading coils and the feedpoint insulator, I used ¼-20 coupling nuts from Home Depot permanently attached to the bolts. The threaded rods screw directly into the coupling nuts during assembly.
Radials
I originally soldered 6 15’ radials into a ring terminal at the base of the feedpoint insulator. With use, the wires broke loose from the ring terminal so I came up with the following solution: I attached a large fender washer to the base of the feedpoint insulater and soldered alligator clips to the ends of all the radials. I used heat shrink over the alligator connector and radial wires for strain relief. I also added 6 short radials.
Base
I designed and built a base for the antenna when used in rocky areas where the spike will not penetrate the ground. It is made of two pieces of 1x2 lumber 24” long. I cut dados in the center of each piece using my router table and drilled holes for a ¼-20 bolt to pass through. CAD Drawing
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© 2012, Stephen Denison
Last Updated: July 29, 2012