[Antennas] J-Pole antennas

[Ron Youvan]

/*snip*/
>> plumbing "T"s and under the short element I add enough copper tubing to be 18 inches long below the 
>> "short" this is a "sleeve balun" and my antennas do not suffer from the usual sensitivity to the 
>> feedline dressing.

> How do you attach you antenna to a mast and do you use a conductive mast?

   I take a full length * of the thicker grade of ridged copper tubing and I cut it 55" from the top 
and install a "T" with the center arm facing sideways. That is the longer element. (above the "T")
I connect the "short" and shorter element to it.  (leaving 41" below the "T" {from a 8' section})
I connect the test feedline across the near bottom of the stub with the used and burnt (from 
previous uses) tiny hose clamps I adjust and wind up trimming about an inch from the 55" section and 
I put a 1/2" pipe cap on it.  I mark the feedline connection point, cut a hole with a large "bur" 
bit on my moto-tool for the coax to come out.

   I use two or three aviation hose bands (screw type) to secure it to a mast or I have put an 
adapter to 1/2" IP (male) and I secured a cast iron flange to the top of a concrete wall and I 
screwed the adapter to it.  It stood there for over 10 years.

   I built two "J" pole antennas (one for a friend) using (1/2") 10 foot long copper coated steel 
ground rods for the long element.  In this case I had to slide the "T" onto the rod and then slide 
1/4" long sections of 1/2" water pipe between the "T" and the ground rod from each end.  (also in 
the cap)  He had the ground rods, (free) and he could slam the point into the ground as a portable 
antenna. Everything else was normal 1/2" thick wall ridged copper tubing. (ID =.61")  Quiet heavy!
It took a lot of heat to solder to the ground rod.

* Costing under $5 with the tax at the time.  (Lowe's or Home Depot)

   The way I feed them, the mounting method or the feedline dress does not effect the tuning of the 
antenna.
-- 
    Ron  KA4INM - The only real problem is death is so final.