6m/2m/70cm Yagi Antenna Built from Old TV Antenna
This turned out to be a great little antenna. It works the 6 meter, 2 meter and 70 centimeter bands. You can use one common feedpoint or two seperate feedpoints depending on how you would like to connect this antenna to your transceiver.
The design is simple and uses dipole driven elements. I kept the antenna small so that I would not need a gamma match or other matching system but you may customize this antenna by using your own desired spacing and number of elements. You'll find more plans and free yagi antenna design software on the internet.
By the way, I've been corrected on identifying the TV antenna elements. The longer elements are actually the back of the antenna. ;)
The driven and reflector elements for 6 and 2 meters came out a bit short but not too far off. You might try the following lengths. Make both the 6 meter elements adjustable. I started with 109" and 102" and landed in the center of the band.
| Band || Ref || Fed || D1 || D2 |
| 6 m ||109" ||103" ||---- ||---- |
| 2 m ||40-3/8" ||38-3/4" ||36" ||35-7/8" |
| 70 cm ||12-5/8" ||12" ||11-7/16" ||11-3/8" |
For spacing on 6 meters I used 54" due to the length of the boom that I had to work with. On 2 meters I started with 15" and on 70 cm 6". Some of the holes already in the boom were close to these measurements and I reused some of the original holes -- but the spacing is still very close to those sizes. For adding more 2 meter elements you can try using an equal spacing of 12-3/8". You may use equal spacing of anywhere from .15 to .25 of a wavelength.
Getting It to Work
Please also notice in the last video how the coax cable is stretched out at a 90 degree angle from the feed-points and is brought down near the reflector. In order to get the dipole driven elements to work the coax cable should be extened out away from the feed-points for a distance of about close to a quarter-wave length if possible.
If you add a 6 meter director and make the boom longer then plan your design on paper so you can figure how to get the coax cable running at a 90 degree angle from all of the feed-points. On the 2 meter and 70 cm driven elements, the cable can run the opposite direction if needed but the cable will still need to be stretched out far enough for them to work.