Your best OTA antenna design?

[northgeorgia]

My brother bought a commercial built antenna and works great (then again, we're in the Atlanta market, so we're flooded with OTA stations here). I was thinking of tinkering and building my own outdoor antenna. I have heard of several designs: Stealth Hawk, Coat Hanger bowtie, Gray-Hoverman. I know there's more out there. Just for fun, I took a 3 yard roll of aluminum chicken wire and used it as a directional antenna with the RCA balun. It actually picked up quite a few stations, but no where near the commercial antenna's ability. Most of the channels are on UHF, but there are two really great ones on high band VHF I would want, too. Any experiences to share?

 

[Bob2011]

The mclapp modified bowties are probably the best all around for capturing nearby VHF-HI and long distance UHF. The gray hoverman if built right can do slightly better on some UHF frequencies but will not get any VHF(ok maybe if you live next to the transmitter ) If you want to really get serious in antenna building then you can move up to custom built Yagis.

Mclapp antenna designs

http://m4antenna.eastmasonvilleweather.com/index.html

 

[Kraven]

Mclapps's an easy built w/ good results. The gray hoverman w/ narods will improve VHF gain. If you're in middle Atlanta, I'd suggest a basic loop antenna and see what you get.

I might have built 20-30 different models, mostly out of fun. The only one I kept was a DBGH (double bay gray hoverman).

Cheers, K

 

[northgeorgia]

Well, I'm actually 50 miles NE into the suburbs... I get good results with my indoor rabbit ears, but some of the variety channels (RTV, France24, etc) won't come in. There are only two VHF channels (good ones though, NBC and PBS), but I can get those with my rabbit ears indoors without too much fuss. I think I'll try the Mclapps. It does sound fairly easy to build.

 

[northgeorgia]

I built a very cheap conceptual model today of the Mclapp (that is...electrical tape, coat hangers, and cardboard!). Although I still couldn't get the Hi-VHF channels, I was surprised at the massive improvement in signal. I could even pull in a few signals that my brother can't get with his commercial antenna when I put the antenna outside. Since it's just made of cheap temporary materials, I have put it back inside and connected it via a switch to my rabbit ears (so I can still watch the VHF channels). Even when inside, it's pretty amazing. As a test, I checked the signal on WATL-TV. 22Q was the maximum with the rabbit ears. It was watchable, but the rabbit ears were fussy about how they had to be positioned in order to get it. Switch to the Mclapp. 74Q signal! Needless to say, I was able to pull in several more channels, including the massive WANN-TV (huge mux of alternative TV and Radio channels, such as RTV) and WPBA-TV (Atlanta's, not Georgia's PBS). I'm wondering whether a solution to my VHF problem would be if the materials were of higher quality and cut to the proper length (I think I read it should be 9 inches instead of the halved coat hanger length) or if it might be better if I somehow connected the mclapp with an old FM antenna from a radio.

 

[Larry1]

I have built a VHF antenna from the design
http://imageevent.com/holl_ands/yagis/hivhf10elyagilorkoe
http://lh4.ggpht.com/_xp43tcwB5ps/TBgusuw9whI/AAAAAAAABAA/nij0uopKPJE/s1024/IMG_6731.JPG
it works very well. I cut 1 1/8" (or might of been 1 1/4") wide strips of aluminum flashing and rolled then into tubes. Used a 1/2" square metal tubing from rubermaid shelving for the long centre tube. It's been up about 1.5 years now and is going great. For UHF I purchased an Antennas Direct 91XG. You probably don't need that powerful of antenna for your area.

 

[northgeorgia]

Larry, did you somehow combine your two antennas so that you have only one coax going into your TV or do you switch between them at the set?

 

[Jim5506]

You can combine UHF and VHF antennas with a UVSJ (UHF.VHF signal joiner) similar to a satellite diplexer, stacking seperate frequencies on a single wire, not mixing similar frequencies.

 

[Larry1]

Larry, did you somehow combine your two antennas so that you have only one coax going into your TV or do you switch between them at the set?

I have the older Channel Master CM7777 pre-amp that has a separate UHF and VHF input. It is a high gain pre-amp and should be only used in fringe areas or you will overload the amplifier. the UVSJ as Jim5506 points out will combine the UHF and VHF signals into one cable. It has one UHF input and one VHF input to combine the two signals. The CM7777 (older versions) has this built in. The newer version (of the CM7777) no longer has this and requires you to purchase the antenna joiner separately if you with to conbine a UHF and VHF antenna for the amplifer input.
Please note, you do not need to use an amplifer with the UVSJ, the UVSJ works fine without an amplifier.

 

[Mitch Dickson]

I build custom antennas. For close to transmitters anything will do. But for the fringe you got to have something good. I am a retired broadcast engineer and helped install 3 of the digital transmitters in our market. My ham call is AE4YW.

For VHF a custom "cut" antenna is the best. I build one that is 9 feet long. It is a log periodic with dipoles for 7,8,9,10,11,12 and 13. This will really reach out 150 to 200 miles if you got enough height. You can find plans for similar log periodics on line. For UHF I build an 8 bay with reflector. Both go on the same pole and are tuned with a rotator.

One of the problems you will run into is the feed system. You can sustain great loss with such garbage as twin lead and cheap 75/300 ohm baluns. You must use ladder line at 450 ohm and wind your own matching balun to hold down loss. Trying to hook coax straight to an antenna defeats the purpose to start with. You will get even less loss to run the ladder line in to the TV and then convert.

Any old General Class Ham should be able to help you wind a 4:1 balun. Watch the length of the 2 pieces of ladder line that feeds the UHF bays, as they have to be exactly the same length to prevent losses from out of phase conditions.

 

[northgeorgia]

I build custom antennas. For close to transmitters anything will do. But for the fringe you got to have something good. I am a retired broadcast engineer and helped install 3 of the digital transmitters in our market. My ham call is AE4YW.

For VHF a custom "cut" antenna is the best. I build one that is 9 feet long. It is a log periodic with dipoles for 7,8,9,10,11,12 and 13. This will really reach out 150 to 200 miles if you got enough height. You can find plans for similar log periodics on line. For UHF I build an 8 bay with reflector. Both go on the same pole and are tuned with a rotator.

One of the problems you will run into is the feed system. You can sustain great loss with such garbage as twin lead and cheap 75/300 ohm baluns. You must use ladder line at 450 ohm and wind your own matching balun to hold down loss. Trying to hook coax straight to an antenna defeats the purpose to start with. You will get even less loss to run the ladder line in to the TV and then convert.

Any old General Class Ham should be able to help you wind a 4:1 balun. Watch the length of the 2 pieces of ladder line that feeds the UHF bays, as they have to be exactly the same length to prevent losses from out of phase conditions.

Wow...great information! Do you happen to have any pictures of one of these 9-footer systems?