Home Made HDTV Antenna
About home built outdoor UHF TV antennas
There are many sites with how-to antenna building instructions for use since the HDTV transition. There are some simple homemade TV Antenna designs that can be built at home with parts you may already have around your house that get the job done. The most common basic
indoor coat hanger on – a – board design can be found here:
This is often referred to as a “bow tie” type.
Another good home builder type is the Hoverman-Gray :
The catch is if you live in an area where TV reception has always been difficult then it probably got more difficult since the transition. For those who live near the transmitters inefficient antennas will work but they don’t work where I live. Any antenna works better on a roof than indoors. From the same test location on my deck the simple wire – on – a – board antenna pulled in two transmitters for me. Store bought rabbit ears got none. The antenna below pulls in 6. Most of those transmitters have multiple feeds so I really can select from 15 channels.
The first thing to do is figure out which transmitters you will be trying to receive. The best place to do that is here:
If the stations you want are less than 20 miles away and LOS (Line of sight) you shouldn’t need anything special. In my case all the stations were from 30 to 50 miles away but fortunately mostly grouped bearing south with only the closest one to the north. Most had obstacles in the way. All were UHF. In some areas there may still be VHF-HI stations. VHF is more forgiving of geographic obsticiles like hills, trees and buildings. It also needs a different type of antenna. The bow tie antenna is UHF and so I won’t be discussing VHF requirements.
Terms that are important to the antenna builder:
Transmitter, UHF, VHF, Bearing, Distance, DB, LOS.
Terms that are less important to the antenna builder:
HDTV, Digital, Definition, Channel.
Lastly you can buy an 8 bow tie type (DB8) antenna for $60 to $80 so if you have to buy very much of your project at the hardware store it probably won’t pay. One reason to build one is if you understand how something works you can get the most out of it.
The Bow Tie Antenna
I think the pictures show what you can do. Most home builders can make one of these. The crucial thing is the shape of the “Vee”. It acts as a sort of tuning fork so you don’t want to change the length of the whiskers or the angle. make them 7 inches long and 3 inches apart at the tips. To pull in distant signals you need more mass. To get more mass add more bowties. DO NOT make the whiskers longer. Keep your array of bowties and connecting wires symmetrical and make sure the balun/s are at the middle. If the connecting wires are not balanced and symmetrical they will un-tune your antenna. You can pull in stations from two directions by making another array and using a second balun and coax combiner. I personally like that approach better than using a rotator so I can surf without rotating.
The antenna has two main components. The bow ties and an optional reflector. The reflector is electrically isolated from the bowties. To reduce wind resistance it should be made of wire mesh or rods. The rods should be 2 to 3 inches apart and 2 to 3 inches behind the bow ties. The reflector makes the antenna more directional but you can make it more multi directional by curving the sides toward the bow ties.
Wood is not a good insulator and is worthless when it gets wet which it will if it’s outdoors. If your bow ties are not properly insulated you will lose signal strength (DB). I saw one builder who recognized the problem and used pvc standoffs then held it all together with screws that went from the bow ties – thru the standoffs – into a wood frame. This same builder also wanted to add mass and made his whiskers longer. Be careful. The longer whiskers may have been pulling in VHF better or he may have been close to the transmitters.
You can substitute materials that will perform the same way. Different types of metals, make the frame of wood, etc.
Most of the Vee’s are made of #8 copper wire. Some are made of Brass rod.
The connecting wires are ordinary insulated household wire only stripped where contact is needed.
The bow tie mount is 3/4 inch pvc conduit pipe.
The frame is 1/4 X 3/4 inch Aluminum flat bars from the hardware store.
The reflector is rabbit fencing.