Sunday, December 4, 2016

This is the Portable Inverted-V Antenna From My Website


Portable Inverted-V
This is based on a design by WE5Y which originally appeared in QST Magazine published by the ARRL. I modified the original
design in how the fishing poles attach to the mast, the top insulator, and length of the fishing poles.

Portable 20-Meter Inverted-V

This antenna is made from a 31 foot Jackite telescoping fiberglass mast. The Jackite is a bit heavier than others and the price is much
better. You can get 2 of these for the price of one of the competitor's masts. If you break a part they are available directly from Jackite.
The dipole design is from an issue of QST magazine with a modification of the cross piece that holds the fishing poles and the top that is the center insulator of the dipole. These Jackite poles came from Ebay. The seller may no longer be selling or they changed their name so the link is removed. In 2007 these were about 35 or 40 dollars each. They can be purchased directly from Jackite
I chose to use a 1-1/4 inch PVC cross and install 2 one-inch reducers in each horizontal end to enable the 1" PVC pipe pieces that hold the fishing poles to be inserted. The fishing poles are 15 ft. crappie poles from Wal-Mart and cost about $13.00 each. Wal-Mart also has the 10 foot ones which are called out in the QST article for about $10.00 each. I chose to just slip the 1 ft pieces of PVC over the fishing pole handles and installed a 1" to 3/4" reducer in the outboard end to center the fishing pole and a 1 inch to 1 1/4 inch adapter on the butt end. This seems to work fine and it makes assembly a bit easier and the whole works a bit lighter. For the top I used a 1/2" PVC T and cemented a piece of 1/2" nylon rod I had to it to mount the apex of the antenna to the top of the mast. The nylon was drilled to fit snugly over the mast before assembly. RG-8X is used for the transmission line although I used RG-58 for the prototype with good results. Both coax types gave me 1:1 to 1:1.5 at the base of the mast across the 20 meter band.

Since I have plenty of speaker stands from doing pro sound work I just use them to mount the mast by removing the plug from the butt of the mast and secure the mast with gaffer's tape. No I do not use duct tape it ruins things. Duct tape has it's places and uses, but not on my masts, cables, and various other things. Speaker stands are stronger and cheaper than the antenna stands. Stands and gaffer tape are available from Parts Express. http://www.partsexpress.com/


Here is the whole works broken down for transport or storage.