Thursday, August 9, 2012

Simple Antennas for the Amateur Radio Operator--a continuing series

KH6JRM's Amateur Radio Blog

Post #182

Stealth and hidden antennas

One of my favorite interests within the Amateur Radio hobby is hidden, disguised, and "stealth" antennas.  I'm amazed at the creative ways amateur radio operators stay on the air despite severe space limitations, restrictive housing regulations, and proximity to power lines.  I'm one of the lucky ones--I do have a backyard.  It's small, but it does allow me to keep most of my HF and VHF antennas outside.  I'm always a little uneasy about using indoor antennas.  There are interference and rf exposure issues indoors which are sometime difficult to solve.

Whenever I feel the need to design a concealed antenna, I often refer to the work of Simone, IW5EDI, an Italian ham residing in the beautiful city of Florence.  Ham radio aside, Florence is a true wonder of the world.  I was in that city many years ago and was impressed with its cultural and historical background, parks, and natural surroundings.  Simone has writen a series of articles on stealth antennas that may give you some ideas on how to get on the air without annoying neighbors or homeowner associations (HOAs).

Simone lives in a third floor apartment which leaves him little room to erect a full-sized antenna for 40 meters.  However, by using an AEA magnetic loop antenna (MFJ sells a similar model) and a ham stick vertical with a tuned counterpoise, Simone is able to pursue his amateur radio interests without drawing attention to his station.  In a series of photographs, Simone shows how well the magnetic loop blends in with the furniture of his patio.  His 40-meter hamstick antenna is bundled with a bunch of fishing poles in the corner of his patio, with a counterpoise wire running through his apartment.  He tunes the ham stick with a wire tuner.  From the street below, one can't tell there are two HF antennas in his apartment.

Although my space problems are not as bad as Simone's, I've lived in places where the backyard is virtually non-existant and the neighbor's apartments are just a few feet away.  I'm blessed with good neighbors who don't seem to mind my homebrew vertical and delta loop in the backyard.  When I'm not operating, these antennas are nested to the ground, both for reducing the environmental footprint and for lessening the chance of a lightning strike.

Apparently, Simone has made antenna concealment an art.  He has submitted several articles to the "dxZone" website describing several vertical, loop, and dipole antennas he has designed and built.  In the use of stealth antennas, Simone says it's best to keep quiet about your antenna projects because "you can get blammed for every TVI, RFI, (and) interference incident in the neighborhood...'loose lips sink ships.'".

For more articles by IW5EDI, visit http://www.iw5edi.com.

That's all for now from this side of the Central Pacific.  Have an excellent day!

Aloha es 73 de KH6JRM--BK29jx15