This is based on a short article from the July 2003 QST (Hints and Kinks Section).
I have refined some of the assembly sections, instructions
and measurements in the article
First, what do you need for materials? You may already have some of them. You'll need
about 2 feet of RG-6 TV cable (about $ .50 at Radio Shack - No, you can't use RG-58 or RG-59, it isn't stiff enough - You don't want
a "Mighty Floppy Duck".). You'll need a BNC connector (about $ 4.00 to $ 5.00, if you don't have one in your connector collection).
If you can find one (available at most electronics parts supply houses), get one for RG-6, otherwise, use a BNC connector made for
RG-59. You'll need some heat shrink tubing. Enough to put two or three layers over the main part of the antenna (cable)
and some to go over the top end of the BNC connector. You'll be able to figure out the size (diameter) after finishing the article.
Lastly, you'll need a small cap for the top of the antenna (I used a cable end cap from a roll of video cable, but even a wire nut
or a dab of silicone seal would do the trick).
Now, let's get to the assembly. Assuming, you have got everything gathered together,
you start with the BNC connector and the RG-6 coax. Attach the RG-6 coax to the BNC connector in the normal way. Cut the
antenna to exactly 16 1/2 inches (measured from the top of the BNC connector). Next, strip off the outer jacket off the coax
down to the top of the BNC connector (use a sharp knife and carefully cut a line from the bottom to the top of the coax and remove
the jacket. Remove the braid from the coax (use a small pair of scissors and clip off the shield braid at the top of the BNC
connector then slip the braid right off the coax). The antenna is pretty floppy at this point. Put on two layers of shrink
tubing over the entire antenna (from the top of the BNC connector to the top of the antenna - be sure to shrink one layer at a time).
This will help to make the coax more rigid. Now, take some larger diameter shrink tubing and cut a couple of pieces about 1 to 1 1/2"
long. Slip these down to the top of the BNC connector, one layer at a time and shrink them. This helps to make the base more
rigid. Take a piece of shrink tubing large enough in diameter to go over the top of the BNC connector and cut it long enough to fit
over the top of the BNC connector and long enough to go over the top of all layers of shrink tubing at the bottom of the antenna.
Now, put this piece of shrink tubing in place and shrink it. Lastly, put your end cap in place on the top of the antenna.
The Quarter Wave Ground Plane
The Pocket J-Pole Antenna
Most all antennas need a counterpoise to radiate effectively. Here are a couple of simple ones that work well and cost very little
to fabricate.