TV antenna advice?

[farmkid]

Does anyone here know much about TV antennas?

Here's my situation: In a couple of weeks, I'll be moving into a house I'm buying. It's a few miles out of town where cable isn't available. The previous occupants had satellite, but that's just out of the budget at the moment, so I'm planning to put up a TV antenna. Here's where I have the question. About half of the stations are in one direction broadcast from about 9 miles away on top of a large hill. The rest of the stations are broadcast from almost the exact opposite direction from about 32 miles away. I would like to use one antenna pointed at the more distant stations and hope to pick up the others from the back. I've been looking at the polar plots of various antennas, but I don't have a lot of background in this kind of thing and I'm not sure I'm reading them right. I'm hoping someone here has more background in antenna design and can help me understand this a little better. So, which design of antenna, bowtie or yagi/corner reflector, picks up more signal from the back? I don't need a wide beam width, but I do an antenna that doesn't reject all the signal from the back.

 

[Mr. B]

Outdoor or indoor?

 

[farmkid]

outdoor

 

[Unimatrix_0]

I'm not 100% sure, but don't they sell omni-directional outdoor antennas? I think I saw a couple of them online for about $100. The one I was looking at looked like a phaser strip bar. According to the web site, you could use it in doors as well, but for optimal service, it should be placed outside.

 

[farmkid]

I'm not 100% sure, but don't they sell omni-directional outdoor antennas? I think I saw a couple of them online for about $100. The one I was looking at looked like a phaser strip bar. According to the web site, you could use it in doors as well, but for optimal service, it should be placed outside.

Yes, those are available, but they generally have lower gain than the directional ones. The area I'm in is served by low-power retransmitters, and I'm not sure something like that would have the gain necessary to receive all the stations. I might look into something like that with an amplifier, though.

 

[Squiggy]

Dumb question but...I'm assuming you have a digital TV or digitial tuner?

 

[Alpha_Geek]

Try http://antennaweb.org

Don't bother with name and contact info there, just give them address and zip codeand you'll be rewarded with a pretty table and map of channels likely to be gotten, and what color code you'll need to tell the drooling idiot at radio shack for the type of antenna you need.

Want more data? This is a more convoluted process, but antennaweb only tells you stations in your immediate TV market. You may well be able to get more channels from neighboring towns. The process to get this info is a little more convoluted, but can be found courtesy of the fine folks at Crutchfield Electronics. Buy something from them to say thanks!

http://www.crutchfield.com/learn/learningcenter/home/antenna.html


So, get the map data, look at the antenna sensitivity patterns, and go from there. In general, corner reflector yagis have less rear rejection than the multi bay flat reflector bowtie types.

Have fun, get a surge suppressor, and watch out for power lines!

 

[farmkid]

Dumb question but...I'm assuming you have a digital TV or digitial tuner?

Digital what?

Yes, of course I do.

 

[farmkid]

Try http://antennaweb.org

Don't bother with name and contact info there, just give them address and zip codeand you'll be rewarded with a pretty table and map of channels likely to be gotten, and what color code you'll need to tell the drooling idiot at radio shack for the type of antenna you need.

Want more data? This is a more convoluted process, but antennaweb only tells you stations in your immediate TV market. You may well be able to get more channels from neighboring towns. The process to get this info is a little more convoluted, but can be found courtesy of the fine folks at Crutchfield Electronics. Buy something from them to say thanks!

http://www.crutchfield.com/learn/learningcenter/home/antenna.html

So, get the map data, look at the antenna sensitivity patterns, and go from there. In general, corner reflector yagis have less rejection than the multi bay flat reflector bowtie types.

Have fun, get a surge suppressor, and watch out for power lines!

I've been to Antennaweb many times, but I'm starting to think they aren't the very accurate. For example, antennaweb lists about half of my stations on channels above 52. Those frequencies were auctioned off and stopped broadcasting with the digital switch over. I found a couple of others that I think are much better, www.rabbitears.info and www.tvfool.com. They give more information that seems more accurate. TVfool even creates maps of reception based on your local terrain. However, they list list the transmitters by call sign, and many of the translators do not have network affiliation information. So, I may see broadcast locations on the map, but I don't know whether or not I want to receive them, since they may be Spanish stations, or duplicates of what I can receive from other towers.

Oh, and I love Crutchfield. I've bought a few things from them over the years.

 

[Mr. B]

A multi-directional antenna such as this model would probably serve you best, although with a stated 70 mile range it could be a tad overkill, especially if the hill your house is on is favorable to reception.

 

[Alpha_Geek]

If you dig down on your TV market in the "listings" section of rabbitears, it'll show you network affiliations. Between that and the city, it may be enough for you to figure out who is who.

Part of the confusion with the digital transition is the channel numbers. I work at NBC29, but the channel 29 analog transmitter is dead and cold and our digital one is humming away, technically on channel 32 while all your sets in TV land show you a "29" on your screen.

70 miles? If you're deep fringe for everything you want to get, buy an amplifier and good coax. Get the type of amp that mounts at the antenna with a dc power injector at the set. These tend to perform better because they are amplyfing the signal BEFORE a long run of coax gets a chance to attenuate it.

 

[Alpha_Geek]

MrB, if his desired stations are close to 180 degrees apart, a corner reflector yagi would probably be better since the multi bay bowtie design has really good rejection of rear signal.

 

[farmkid]

A multi-directional antenna such as this model would probably serve you best, although with a stated 70 mile range it could be a tad overkill, especially if the hill your house is on is favorable to reception.

Yeah, I've been looking at that one and it's little brother, the DB4. What I'm trying to figure out, though, is how this style compares to the yagi/corner reflector style (such as this one) in how well they pick up signals from the rear.

 

[farmkid]

MrB, if his desired stations are close to 180 degrees apart, a corner reflector yagi would probably be better since the multi bay bowtie design has really good rejection of rear signal.

Thanks. Now, how good is the corner reflector yagi style's rejection of rear signal. The signal from the rear is quite a bit stronger than from the front, but I don't really know how much stronger. If I want to pick up that signal from the rear, do I need to be sure I get a very high gain antenna? Will that vary much from one model to another, or will most of them be about the same?

ETA: In reading reviews of the DB4 and the Channel Master 4221, several people have commented on being able to pick up stations from the back rather well. Will a corner reflector yagi do even better?

 

[Alpha_Geek]

Corner reflector yagis typically let more signal from the back come in than a bowtie and planar reflector.

Gain is a trade-off. The higher the gain, the more the antenna is going to get stuff where it's aimed from, instead of where it's not pointed. The gain figure is a comparison to a theoretically impossible antenna that gets signals equally good in all directions.

A simple dipole antenna gets about 3db gain over this "isotropic" antenna because the dipole can't pick anything up anything its own axis, and the sensitivity picks up as the source moves closer to perpendicular from the dipole. A horizontal dipole would have a sensitivity pattern that looks alot like a figure 8.

Look at the patterns of the antennas you're think about with this in mind, it may help you see which might work better for your particular application.

 

[Ar-Pharazon]

Radio Shack (and others probably) carry an outdoor antenna rotator. Pre-amplifiers too, if that kind of thing works with the digital signals.

They were pretty popular back in the day around here, halfway between Chicago & Milwaukee. Add in the potential for Madison stations, and you could get a wide variety, especially when Red Dwarf was carried on one of the Wisconsin PBS stations but not the Chicago one.

 

[Alpha_Geek]

TV antennas and antenna amps don't care if it's an analog or digital TV signal. It's all RF to them.
If the two places the OP wants are really close to 180 degrees apart, he may be able to get by without a rotor.

If you do go with a rotor, get a *real* telescoping mast or 3 leg tower and not the tiny 10 foot stackable sticks of pole. There will be a lot more mass up there at the end of a long lever.

 

[Irishman]

outdoor

Try either the Clearstream 2 or 3. Their range and omni-directionality might be what you want.

 

[Saturn0660]

Radio Shack (and others probably) carry an outdoor antenna rotator. Pre-amplifiers too, if that kind of thing works with the digital signals.

They were pretty popular back in the day around here, halfway between Chicago & Milwaukee. Add in the potential for Madison stations, and you could get a wide variety, especially when Red Dwarf was carried on one of the Wisconsin PBS stations but not the Chicago one.

Pre-Amps do work with Digital.. However, be careful. You can Over-boost..

 

[Alpha_Geek]

The split design that has the power injector near the set and the amp up on the pole helps in those overload situations. Just unplug the injector.

If the OP is in the deep fringe area it won't be an issue though. (CEA blue violet, or pink antenna codes, maybe even red in some cases)