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1 edit | Antennas "Antennas are cheap, and they're old technology so the price likely won't be changing soon."
Not so fast, friend; recent antenna technology has benefited from computer modeling. The newer Winegards, etc., are good designs and affordable, especially if you buy them at the wholesale price. Since HD is carried on UHF frequencies, the antennas tend to be small compared to VHF antennas for a given amount of gain. It is not a bad idea to buy the highest gain "outdoor" antenna you can afford. If the signal level is too high for the input of your set, pad it down with a pad at the input to the TV. The idea is to obtain as much signal as possible from the desired direction; the higher gain antennas are also the most directional and thus less prone to multipath interference. Use quad-shield RG-6 cable with the "snap-and-seal" F-connectors, seal all outdoor connections with stuff made for that purpose (found at Radio Shack), use lightning protection, and don't bend the cable too sharp (sharp bends cause standing waves in the cable).
The inexpensive antennas work well outside in climates like Southern California. In places like New England, if you can get by putting one in your attic, do so. You will sacrifice at least 3 dB of gain, but your antenna won't corrode (and thus act like a diode) or blow apart. Where I live I would not dare put a large inexpensive antenna on my roof; it would easily blow down within a few months.
If you really want a good outdoor antenna that is built to last in severe weather, buy a Scala. They are expensive (over $350.00) but they are the best made period. See:
»www.kathrein-scala.com/uhf-tv.htm
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"Remember, Comrade, people who are willing to destroy an efficient telephone system may not be playing with a full deck." | |
Time4aNAPPremium
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Des Plaines, IL | said by Alex G Bell:It is not a bad idea to buy the highest gain "outdoor" antenna you can afford. If the signal level is too high for the input of your set, pad it down with a pad at the input to the TV. The idea is to obtain as much signal as possible from the desired direction... A caveat: if you are in an area where there are two or more physically separate transmitter sites for your market, more antenna gain might hurt more than help. For example, on the northwest side of Chicago, a "fringe" antenna could give great reception for stations transmitting from Sears Tower, but reject stations atop the John Hancock Center. Or the gain from an antenna pointed halfway between the two, in order to get balanced reception, would be wasted. Granted, you might get lucky with side lobes, but IMO the average viewer would be better off with a less expensive, lower gain antenna.
In areas where the separation is more than a few degrees (Post-9/11 NYC, SF Bay Area...), you have a whole new problem. Neighbors tend to consider rooftop antennae of all kinds an eyesore. Putting up one antenna that's twice as long as the others in the neighborhood will raise some eyebrows. Putting up two or three is just asking for trouble.
Chances are that if you're surrounded by transmitters, none of them are very far away. So an omni or multiple compact directionals can work without the risk of getting local government involved.
...the higher gain antennas are also the most directional and thus less prone to multipath interference. True that. The problem is that the places with the worst multipath tend to be places with the least room for an external antenna. 
Use quad-shield RG-6 cable... ...or if you want to go all-out, use shielded 300 Ohm balanced line cable. Balanced lines give the best common mode rejection. You must use stand-offs to keep it 2-3" away from other stuff, but if you want the best, that's the way to go.
In places like New England, if you can get by putting one in your attic, do so. You will sacrifice at least 3 dB of gain, but your antenna won't corrode (and thus act like a diode) or blow apart. The house that I grew up in had an attic antenna. It works quite well. And you get a rock-solid picture no matter how windy it is outside.  | |
 tschmidtPremium,MVM
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said by Alex G Bell: If you really want a good outdoor antenna that is built to last in severe weather, buy a Scala. Thanks for the antenna vendor link.
We live in NH about 50 miles from Boston. Currently have separate roof mounted VHF/UHF antennas and a rotor. I made sure they were securely mounted and have not had weather problems over the last 25 years. Even including multiple lightning strikes around the house.
I had assumed we were out of luck getting HDTV over-the-air since it is UHF which has shorter range then analog VHF and we have lots of mountains out here creating multipath problems. Hadn't worried about it too much since we have until Feb 2009 before analog stations to go dark. I figured by 2009 Verizon would have installed FIOS to our town. But with the impending sale of Northern NE I figure we'll be on DSL for a long time.
I'm getting an HDTV tuner card for my daughter's PC. That will give us some real world experience.
/Tom | | |
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1 edit | reply to Time4aNAP
"A caveat: if you are in an area where there are two or more physically separate transmitter sites for your market, more antenna gain might hurt more than help. For example, on the northwest side of Chicago, a "fringe" antenna could give great reception for stations transmitting from Sears Tower, but reject stations atop the John Hancock Center. Or the gain from an antenna pointed halfway between the two, in order to get balanced reception, would be wasted. Granted, you might get lucky with side lobes, but IMO the average viewer would be better off with a less expensive, lower gain antenna."
This is entirely true if you live in such an area.
"...or if you want to go all-out, use shielded 300 Ohm balanced line cable. Balanced lines give the best common mode rejection. You must use stand-offs to keep it 2-3" away from other stuff, but if you want the best, that's the way to go."
If your antenna and TV have 300 ohm output/input (very uncommon today). The loss on RG-6 is low, however, and the stray pick-up on quad-shield is much less of a problem than the potential interference caused by routing twin-lead through walls and down poles, etc. A long time ago there was such a thing as shielded 300 ohm twin-lead, but I don't know where one could find it today; it would likely be expensive and it is difficult to terminate or run through a wall jack/plug.
"The house that I grew up in had an attic antenna. It works quite well."
And it also has the advantage of not acting like a lightning rod! Keep the antenna at least a wavelength and a half away from everything else in the attic if possible to avoid interference.
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"Remember, Comrade, people who are willing to destroy an efficient telephone system may not be playing with a full deck." | |
Time4aNAPPremium
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Des Plaines, IL | said by Alex G Bell:If your antenna and TV have 300 ohm output/input (very uncommon today). The loss on RG-6 is low, however, and the stray pick-up on quad-shield is much less of a problem than the potential interference caused by routing twin-lead through walls and down poles, etc. A long time ago there was such a thing as shielded 300 ohm twin-lead, but I don't know where one could find it today; it would likely be expensive and it is difficult to terminate or run through a wall jack/plug. I can imagine that finding fresh, new shielded 300 Ohm antenna lead wire wouldn't be easy. But thanks to the Internet, it's easier than ever, really. All that's required is a balun to convert from balanced to unbalanced operation. Most new TVs come with one, to be used with the rabbit ear antenna that comes with the set. Higher quality parts can be purchased online, or at a local Radio Shack.
I admit that it's been a while since I have seen a TV receiving antenna (aside from the aforementioned rabbit ears) up close. The last time I did, it was a standard horizontal dipole with reflector and director elements behind and ahead, respectively. It used a weatherproof balun to accommodate the coax downlead, but was otherwise a 300 Ohm balanced design.
I'm not saying that everyone should use 300 Ohm antenna wire. As I mentioned, it takes a great deal of care to set up properly. But there are situations where it has distinct advantages over coax. For the hobbyist videophile, it makes a nice weekend project. Those who aren't interested in such things can use coax and be done with it. | |
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| Thanks for the trip back in time ... I installed many thousands of feet of twinlead as a TV Shop kid in the late 70s and early 80s. I had a callous on my middle finger for years from screwing in standoffs. Interference wasn't much of a problem, and we could always try shielded if it was. But coax always required a preamp on the roof.
But enough of that nostalgia. Now I live 1-3 miles from the local towers and I can see all of them from my upstairs window. Analog reception is horrible with multi-ghosts on just about everything. That's the main reason I am hemorrhaging the grand sum of $15 per month for basic cable.
So is there a page somewhere discussing the finer points of OTA HD in strong signal areas? Thanks.
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Time4aNAPPremium
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Des Plaines, IL | said by ArgMeMatey:Thanks for the trip back in time ... I installed many thousands of feet of twinlead as a TV Shop kid in the late 70s and early 80s. I had a callous on my middle finger for years from screwing in standoffs. Interference wasn't much of a problem, and we could always try shielded if it was. But coax always required a preamp on the roof. Thanks for reminding me that I'm old.  I used to equate coax with "new and exciting", but then I studied electrical engineering, and learned the truth about transmission lines. The old stuff wasn't that bad after all. Most of the problems came when people didn't know they needed standoffs.
Now I live 1-3 miles from the local towers and I can see all of them from my upstairs window. Analog reception is horrible with multi-ghosts on just about everything. That's the main reason I am hemorrhaging the grand sum of $15 per month for basic cable.
So is there a page somewhere discussing the finer points of OTA HD in strong signal areas? Thanks. None that I know about. That's one topic that I'd love to discuss, though. I was in the same boat when I lived in Chicago. I've lived in different parts of the city, ranging from less than a mile away to five miles away. The ghosting made watching TV with an inside antenna nearly impossible.
As long as you have line-of-sight and can put up a rooftop antenna, your best bet is a highly directional antenna pointed at each tower. Depending on their spacing relative to you, and what's in the opposite direction, you might have better luck pointing a single high-gain away from the towers, and rotating it slightly until you get the best picture. Highly directional antennae often have closely-spaced lobes with sharp nulls in between. With a lot of patience and a little luck, you might find a lobe/null pattern that blocks out the sources of the ghosts. | |
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