The antenna

My antenna is a center-top loaded vertical radiator.  It features a 3/4-inch ID copper pipe mast from trailer-hitch height to the bottom of the coil.  Everything from the coil up removes from the car but the mast and the steel support remain unless unplugged from the trailer hitch which can take a few minutes.  The size of the cage was dictated by my desire to be able to carry the antenna indoors.  The core of the top section is 5/8-inch fiberglass rod.  The entire assembly is strong and rigid.

The 75-meter coil is 9 inches in diameter and 6 inches tall.  There are 16 turns of #10 copper.  There is a tap for 40 meters.

The 160-meter coil is 9 inches by 6 inches with 36 turns of #12 wire.

The cage is 19 inches tall by 16 inches in diameter and lives about 7 inches above the coil.

The mast (below the coil) is approximately 54 inches tall.  The overall height of the antenna is limited by the need to drive under low overpasses without tearing the antenna off the car.  The top of the cage is a few inches over 7 foot from the ground.

The antenna impedance varies by band and is matched using per-band broadband transformers.

The capacity cage

160-meter coil design

Antenna videos

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