Plumbers Delight J Pole Antenna Project
Build a rugged and economical 2-meter J-pole antenna using copper plumbing parts.
Description
Constructing a 2-meter J-pole antenna from readily available copper plumbing components offers a robust and cost-effective solution for VHF operation. This design, dubbed the "Plumber's Delight," functions essentially as a half-wave dipole fed by 50-ohm coax via a gamma match. It incorporates a quarter-wave copper tubing support, which, when affixed to a metal mast or tower, enhances forward power in the direction of the radiating elements.
The original configuration utilized a small ceramic trimmer capacitor for the gamma match, suitable for up to 10 watts. A subsequent modification replaced this with a 50 pF variable capacitor housed in a plastic enclosure, accommodating higher RF power and improving weather resistance. The antenna elements are secured using a copper "T" fitting, and an SO-239 connector mounts directly to this fitting.
Performance includes gain away from the support mast, and tuning is straightforward by adjusting the gamma match capacitor for a 1:1 SWR. The total cost for materials, excluding the capacitor and coax, can be under $10.