Introduction: Hidden Television Antenna
If you want television reception but have no desire for an ugly indoor TV antenna nor room for one, here is your solution. A very effective antenna can be made from a few odds and ends costing almost nothing. The antenna is made up of four strips of adhesive copper strips of the type used in hobby stained glass making. Two are mounted horizontally on one side of window or patio glass while the other two strips are mounted on the other side of the glass exactly lined up. Two wires are soldered onto the inside pieces. A piece of coax has one end cut off and wires are attached to the inner and outer conductors and these are attached to alligator clips. A barrel "F" connector is used to attach the other end of the coax to another coax that goes to the TV. One coax could be attached directly to the window antenna permanently and the other end to the TV but this would defeat the portability of it. There is some signal level being lost through the alligator clips and barrel connector but it didn't seem to be too much of a problem.
Step 1: How Does It Work?
The copper strips on the outside of the glass act as a dipole antenna. The lengths of the dipole are resonant for the middle of the UHF band. A TV signal passes through the outside dipole and induces a tiny RF voltage of opposite polarities in each arm. This electrical signal is capacitively coupled through the glass to the other dipole which is electrically identical. The signal is taken off the second dipole and sent through the coaxial cable to the TV. This technique has been used for many years to pass a signal through the windshield of a car to an outside antenna. It has been used mainly for improving cell phone reception inside cars. I have found it works well for windows in houses too. I have demonstrated its use on a small piece of single pane window glass in the photos for convenience, but I have tried this on actual windows and it works well.
Step 2: Parts Needed
1) Roll of adhesive copper of the type used in hobby stained glass making. Can be obtained at well-equipped hobby stores or online.
2) (2) Alligator Clips. Purchase at an electronics store.
3) Two pieces of RG6 or RG59 coax. One 6 feet and one 3 feet. Get at an electronics store.
4) Roll of solder and soldering gun, measuring rule, wire strippers and diagonal cutters. Purchase at an electronics store.
5) Roll of vinyl electrical tape or heat shrink tubing. Purchase at an electronics store.
6) Braided hookup wire. Can be purchased at a hardware or electronics store.
Step 3: Mounting Outside Copper Strips
(1) Cut (4) strips of copper 4 3/4" long and stick two of them on the outside of window or patio door horizontal to the floor. Make sure that the glass is cleaned with window cleaner before mounting for better contact. The strips should be 1/4" apart. Mount at any distance above floor or window sill that is most convenient.
Step 4: Mounting Inside Copper Strips
Mount the inside copper strips in exactly the same place on the inside of the glass.
Step 5: Solder Wire to Inside Copper Strips
Solder two pieces of 6" hookup wire to inside copper strips as shown. Do this once the copper strips are mounted on the window. Use only as much heat as is needed to make the connection or you might damage the strips. Make sure you strip and tin the other ends of the wire so that the alligator clips can attach giving good electrical connection.
Step 6: Cut End Off One Piece of Coax.
Cut the end off one piece of RG6 or RG59 coax and solder wires to the inner and outer conductors. Wrap the solder connections in electrical tape. Cut off each wire at three inches and leave stripped ends protruding. Slip a piece of heat shrink tubing over the wires that have been taped up or wrap the whole assembly in tape allowing about an inch and tin the ends with solder.
Step 7: Solder Coax to Alligator Clips.
Take the tinned wire ends and solder them to alligator clips.
Step 8: Put Everything Together
Insert barrel connector in one end of coax with alligator clips. Clip alligator clips to window wires. Take a 6 foot coax and attach one end to barrel connector and other end to TV.
Step 9: Connect to TV and Run a Scan
Depending on which direction your window is facing, you could get signals from up to 40 miles away. To get local signals you don't need to be aimed directly. I have one on a south facing window and my local stations are 40 degrees off to the side of the direction of the antenna and they all come in very well. I am in a bad reception area with a gently sloping hill in front of me to the south. I can sometimes get a station 40 miles away and over the hill depending on the atmospheric conditions. The beauty of this antenna is that it can be stuck on a window and not noticed. When you want to use it you just clip the alligator clips onto it and it instantly works. The copper foil is easily removed from the glass when needed, with a small blade.
If this Instructable is of interest, perhaps you might be interested
in my ebook on Amazon Kindle. Ten Antenna Projects for HDTV by Mr Electro https://www.amazon.com/s/ref=nb_sb_noss?url=node%3D154606011&field-keywords=mr+electro