Am going to build a copper J-Pole antenna for two meters tomorrow at something called Second Sunday Tech Session. Actually, I’ll build two – one for home and one for cabin QTH.
Question: So what is a J-Pole antenna? Answer: According to my most-recent (1994) ARRL Antenna Book (I know I am chancing it that physics may have changed in past 17 years), a J-Pole is a “vertical antenna (that) doesn’t have stringent grounding requirements and can be made from easy to find parts.” I know my parts will be easy to find tomorrow as I have pre-purchased kits from the project organizer Jim Reed, N4BFR, whom I look forward to meeting.
Question: why copper; why not aluminum like normal antennas? Answer: I dunno. Copper’s a better conductor than aluminum so maybe it’s a better radiator too? Maybe it’s because copper is more attractive when it is properly aged and will enhance your property values more than mill-finish aluminum. Maybe Mr. Reed has a supply of copper tubing left over from a plumbing project he wants to get rid of. I’ll find out why tomorrow.
This edition of the ARRL Antenna Book was not all that helpful as it had plans for a mobile J-Pole (not for me; I just bought a trim-looking black dual band whip for my car for almost $100 so now I have to protect my investment) and a maritime J-Pole (only boat I have is a canoe and as we know, there is very little repeater coverage in valleys where you find the rivers), so I looked elsewhere for info.
Aerials by Kurt N. Sterba & Lil Paddle is fun to read but not organized, and has no table of contents nor index so looking up anything is impossible. W1FB’s Antenna Notebook and the 2011 ARRL Handbook do sport indices and TOC, but neither even mentions J-Poles. What am I getting into?
Come back later for pics and a report.