Articles for Amateur Radio Newsletters aimed at new hams
 written by Gerry Crenshaw, WD4BIS, Rowlett, Texas

 

 

NHP #19: Invisible Antennas (almost)

You can put up a HF antenna, almost anywhere!

With all the upgrades in our club lately (including me), one of hot items of discussion on the repeater is how to get on the High Frequency (HF) bands when you live in an apartment or condo. Ideas for reduced space, compact, or invisible antennas for this kind of dwelling have been numerous and interesting.

First, let's remember that the name of the game here is to put radio frequency energy into the air. Never lose sight of that. How we do it is secondary. How we hide the antenna is limited only to the imagination. With a good antenna tuner, almost anything metallic will work. But remember this, your bandwidth is very narrow. Usually, if you vary your frequency more than ten kilohertz you will have to re-tune.

Your First Concern

  Always remember that when you are in the apartment/condo environment, you have lots of neighbors, so be a good one. After you assemble your antenna, tune up your radio and antenna and transmit briefly while your spouse or a friend is listening to the TV and stereo. If you get any kind of interference, quit and work on the problem. Low-pass filters often help for these kinds of problems. Running reduced power helps for other interference problems. Grounding your radio is an absolute must. A good ground in an apartment is often hard to get, but if you can find a copper cold-water pipe in your apartment, that is a good first step. Use a "saddle clamp" to get a good connection. Be aware that the hot-water pipes tend to be "ground isolated" through the hot water heater, so avoid them.

What Next?

Refer to one of the ARRL publications and look at the block diagrams for "Connecting Radio to VSWR meter to Tuner to Antenna". After you are sure you have this right, look at the construction details for dipoles and random wires.

HF antennas in an apartment or condo can be done. Just bear in mind a few things. First, be a good neighbor and if some one has an interference complaint try to solve it. Next, with this kind of set up you can not be a "BIG GUN" so don't try to be. You won't make all the contacts, but those that you do will be special. Experiment. Part of this hobby is trying things and learning and having fun.

One of the biggest thrills I have had was working Germany on 30 foot of 28-gauge wire from my first apartment. That contact sparked a lifetime interest in this hobby.

73 and GL from
Gerry WD4BIS

 

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Copyright 2005 Gerald Crenshaw WD4BIS. All rights are reserved.

Permission in advance is granted to those who use this for non-profit Amateur Radio club newsletters as long as it is used unmodified including this copyright notice and that notice is given to the author via email (wd4bis@arrl.net). In addition, please forward a copy of any newsletter this appears in to: Gerry Crenshaw WD4BIS, c/o GARC, 1027B W. Austin St, Garland, TX, 75040

Web site maintained by Janet Gobeille Crenshaw (WB9ZPH)