Wednesday, June 21, 2017

Random Wire Antennas. Post #1166.


Random Wire Antennas
(http://www.arrl.org/random-wires).
Accessed on 21 June 2017, 23:50 hrs, UTC.
Please click link or insert title into your browser to read the full article.

Comment:

Random wire antennas have been around since the dawn of Amateur Radio early in the 20th century.  Properly designed and attached to a suitable ground radial or counterpoise system, a random wire antenna will perform well and give you many contacts on Field Day or any other portable operation.

This article from the ARRL, gives you all the information you need to make a simple, inexpensive, and efficient random wire antenna.

The best length of a random wire antenna seems to be around 1/4 wavelength of your chosen band.  If you want to operate from 80 through 10 meters, make the wire length to accommodate the 80 meter band (around 135-feet/41.158 meters). For multiband HF use, an antenna "tuner" and a ground radial/counterpoise system are required.

According to the ARRL, a counterpoise or ground radial system supplies the "missing half" of your antenna and will do a lot to reduce RF in the shack:

"A counterpoise is simply a long, insulated wire that attaches to the ground connection on your antenna tuner. The best counterpoise is 1/4-wavelength at the lowest frequency you intend to use. That’s a lot of wire at, say, 3.5 MHz, but you can loop the wire around the room and hide it from view. The counterpoise acts as the other “terminal” of your antenna system, effectively balancing it from an electrical standpoint."

Good luck on Field Day--24 and 25 June 2017.

Aloha es 73 de Russ (KH6JRM).