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.
Invisible Random Wire: A length of small-gauge enameled wire (my first apartment antenna used #30 wire) between a window and any nearby structure or tree. This will work with modest success. The longer the better, but "space available" is what you use. Remember that this type of antenna will come down in a stiff breeze so be prepared to replace it often. One thing to avoid is picking up a roll of electric fence wire. This kind of wire has so large a resistance that you are putting up a dummy load rather than an antenna.
Gable Dipoles: Wire dipoles stapled along the gable of a house or an apartment work quite well. An antenna with traps is hard to hide, so a dipole antenna per band with a quick-disconnect connector like a BNC is a must. Choose an insulated wire that matches the color of the wood trim of your apartment or house. I had a sharp-eyed apartment superintendent catch me once because of the wire color. I also have to admit that a green wire against an off-white wood was a poor choice. My explanation that I would be using them for Christmas lights did not wash.
Copper Tape Antennas: These usually work quite well but can be hard to hide. The wide copper tape is just too obvious. If you promise to paint over it when you have it mounted, you can be in DX Heaven. Several different manufactures make these and you have to follow the instructions exactly. Don't read anything into the instructions. Just follow them to the letter.
Slinky Antennas/Dryer Duct Antennas: Dipoles made of Slinkys or out of flexible clothes dryer ducts can be supported on monofilament fishing line. A hallway or unused wall can be used for this kind of antenna. Again, follow the construction details for a dipole. When making the solder connections to these devices, be sure and scrape the insulating material well and make sure that the solder connections are solid.
Mobile Antennas: Mobile Antennas such as the Hustler or Outbacker brands can be used in apartments. I have used a large flowerpot, filled it with QuickCrete and placed a piece of large-diameter EMT conduit in the pot for the mast. An Outbacker antenna was mounted to the mast, then placed on the patio of my second-floor apartment. A small American flag was placed on top of the antenna. The same thing can be done with a Hustler antenna. In my wife's case, she had a propane grill on the patio and mounted the antenna to the grill. Just remember not to cook and transmit at the same time. One hundred watts can really tingle when you are flipping burgers.
Screen Doors, Gutters and Railings: Prior to trying to use these, first check to see if you have a resistance path to ground. If you see even a slight resistance to ground, give up the idea: an antenna doesn't work if it is grounded. If, however, you don't see any resistance to ground, give it a try and slowly increase your power. Apartment complexes are funny when it comes to appliances. When a friend of mine used the guttering of an apartment complex and transmitted, the range/ovens in ALL of the apartments turned on. This did not make him many friends.
The DOOR Antenna: This reduced-space antenna has the advantage of being somewhat directional. If you have an unused door to a room in your apartment or condo, start by making an "X" with masking tape from corner to corner. Mark the tape every half-inch from the outside edges. Using pushpins place a pin at every mark on the "X". You have now made a form for the antenna.
Using small-gauge enameled wire, start at the bottom of the door. Anchor the wire to the outside-most pin. Wrap the wire in a spiral fashion using the pins for guides. When the antenna is finished, you get your directionality by moving the door in and out.
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
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 ([email protected]). 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
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