Indoor Antenna Projects 1
Indoor Antenna Projects 1: Practical indoor antennas for everybody
HF Indoor Antennas:
Some practical indoor antennas that can be built by anyone:
** HF foil antennas
** VHF/UHF discones
** Wire beams
** Attic VHF/UHF rotables
** Tape antennas
** Telescoping VHF/UHF indoor beams.
HF Foil Antennas
HF foil antennas are too weak in their physical construction for outside use. Foil antennas are just what the title implies, foil. They are made from ordinary aluminum foil, the kind used for heavy duty cooking, such as roasting a turkey.
This antenna goes in the attic of your home or condo. Apartment dwellers may have a time with this antenna depending on their location within their complex. Materials needed are two to three rolls of aluminum foil, copper tape with electrically conductive glue, a staple gun and staples, and coax with connector. By stapling the foil in a loop or dipole configuration on the attic rafters, a simple antenna can be formed.
===================== ======================= || balun if desired | | | coax to shack
========================================== | | | | | | | | | | | | ==================== ===================== || Balun if desired | | coax to shack
These two configurations are excellent when used with a tuner for the various bands on amateur radio and SWL listening. They are cheap to install and can be made into other configurations, by the amateur, if desired. A relay can be installed to provide dual antenna configurations if needed. With this device you can switch between a dipole and the loop for different propagation conditions. Size and shape is dependent on the attic structure.
Connections from the foil to the coax or BALUN are via the copper tape. There are copper tapes available on the market that are used for EMI applications. These tapes are expensive so if you can get a piece of some of that tape from a buddy, it will work wonders for you.
Otherwise, there is a trick with regular copper tape and the aluminum foil that you can do. It’s a simple folding technique that insures a good connection and yet requires no soldering except for the coax/BALUN connection.
Practical indoor antennas for everybody
====================================== Aluminum |——————————|| foil | =============================== |————————————– Copper tape
This folding method insures good contact on more than one surface. One warning, do not leave air gaps, as it will have a capacitive effect. Solder doesn’t stick to Aluminum foil very well. With enough heat, you can solder anything. Too bad the aluminum foil won’t hold up at that temperature and neither will the solder.
You now can solder leads to the BALUN or solder the coax direct to the copper tape.
For an indoor antenna, the foil antenna works rather well. It can out perform a vertical and pull in the weak ones with ease. I think you’ll find it one of the most inexpensive antennas you can build yourself.