The PORTABLE or 'BASE' 2m/70cm
Copper-pipe "J" Antenna
by N6JSX 08/2013
This is my revised "BASE" 2m/70cm Copper-Pipe "J", a "how-to DIY" with an optional method to make a "PORTABLE" dual-band "J" for hotel travelers, restricted apartment dwellers, or for limited balcony/patio use. See my previous "J Pole Antenna Stand" project here!
This revision is easier to build while becoming more robust and durable than my previous design. I'm confident you will find this portable "J" to far exceed any other antenna, in the same setup, to more than tripling your 2m & 70cm (440MHz) performance!
Here is a step-by-step to make a portable (or base) 3/4 inch copper-pipe "J" that breaks down into four (~24" long) pieces for easy transporting. This design uses a Bungie-cord to keep all pieces together when unassembled and then insures good element conductivity when assembled. A threaded pipe adaptor was added to the "J" for use with a portable PVC stand or for outside balcony/porch/patio mast mounting.
For a rigid robust base "J" omit theBungie-cord and element items in
red in the text of the article to follow, not the drawing on this page.
The original Zepp "J" design dates back to the early 1900's as an HF antenna hung from the tail of Zeppelin airships. Years later the "J" found its home on VHF/UHF when the following attributes were discovered:
Requires>NO< ground plane creating a very low angle of radiation,
Easy and inexpensive to make giving the best value for the effort;
It has great flatland performance for mobile, marine, or base operations.
See the rest of this article as a pdf download here!
It contains complete build instructions plus a novel portable base stand for the J antenna.
But wait, there is more!
Also see the "Foxhunt" tips and tricks for hiding your "Fox" at the end of the pdf file.
See also The CB-whip HAM "J" Antenna by N6JSX (pdf document download)