Updated TV Antenna Thoughts

   / Updated TV Antenna Thoughts #81  
I've installed at least 50 of these antennas over the years in the far-flung suburbs of Atlanta. Every installation except one was in the attic of the home. Over time I began hanging them with wire from a rafter from a reasonably high point in the attic.

70 something channels on one I installed last Tuesday, never once needed an amp or anything.

Amazon.com: Channel Master CM-4228HD High VHF, UHF and HDTV Antenna: Home Audio & Theater

If you are in metro Atlanta you can get this antenna from Dow Electronics in Duluth GA for $73.00
 
   / Updated TV Antenna Thoughts #82  
Ain't supposed to butt the amplifier up to the amp's power supply. Amp is installed at the antenna to overcome losses in the coax down to the splitter(s). Amp's power supply goes as close as possible to the TV's tuner.

The installation instructions say the power supply can go anywhere from a few feet to 150' away from the amp. It doesn't affect anything.
 
   / Updated TV Antenna Thoughts #83  
We hams get a kick out of looking at antenna "specifications" When TV antennas are rated in "miles" How funny. Instead of rating an antenna in forward gain, 3 dB apertures and front to back and front to side ratios. Of course we understand WHY antenna specifications are never given.

One reason is because 99% of the consumer population would not understand them, and the VERY other good reason to not list specifications if because then you don't have to really say how good your antenna is. No lying needed. Just don't publish them at all and give a vague "spec" like how many miles. That is such a laugh because it does not take into factor the terrain, the TV transmitters output power or tower height, or really anything. It is a totally meaningless "spec" Totally.

This is similar like the "specifications" given for consumer handheld two way radios. "Good for 30 miles".. :laughing: Yeah, if the other guy is in an airplane and has a totally unobstructed line of sight to you and you are in a clearing holding the radio up above your body. I suppose. But then again if you posted reciever sensitivity is .12uv for 12 dB SINAD quieting and transmitter was rated for 750 Milliwatts output. I suppose not many would take the time to actually look that up now would they? Let alone posting adjacent channel rejection, or stability, or front end rejection.

They just want to know how many miles the darn thing will "talk" hint: take the stated distance and divide by 20 or 30, and you will be in the ballpark. :) in "average terrain" What ever that is!

The end result? Consumers have no actual way of comparing a product before they buy it. But that is figured in now isn't it?:)
 
   / Updated TV Antenna Thoughts #84  
We hams get a kick out of looking at antenna "specifications" When TV antennas are rated in "miles" How funny. Instead of rating an antenna in forward gain, 3 dB apertures and front to back and front to side ratios. Of course we understand WHY antenna specifications are never given.

One reason is because 99% of the consumer population would not understand them, and the VERY other good reason to not list specifications if because then you don't have to really say how good your antenna is. No lying needed. Just don't publish them at all and give a vague "spec" like how many miles. That is such a laugh because it does not take into factor the terrain, the TV transmitters output power or tower height, or really anything. It is a totally meaningless "spec" Totally.

This is similar like the "specifications" given for consumer handheld two way radios. "Good for 30 miles".. :laughing: Yeah, if the other guy is in an airplane and has a totally unobstructed line of sight to you and you are in a clearing holding the radio up above your body. I suppose. But then again if you posted reciever sensitivity is .12uv for 12 dB SINAD quieting and transmitter was rated for 750 Milliwatts output. I suppose not many would take the time to actually look that up now would they? Let alone posting adjacent channel rejection, or stability, or front end rejection.

They just want to know how many miles the darn thing will "talk" hint: take the stated distance and divide by 20 or 30, and you will be in the ballpark. :) in "average terrain" What ever that is!

The end result? Consumers have no actual way of comparing a product before they buy it. But that is figured in now isn't it?:)
Exactly, well stated.
 
   / Updated TV Antenna Thoughts #85  
Exactly, well stated.

Thanks. But I would actually take the time to compare products before I purchase them, and I would be happy to help anyone else understand these things. Any of us can learn if we want to do so. I am no genius (as many of you can attest:) ) but I have taken the time to learn a few things, and I would love it if we could get something to work with to make our consumer choices. But alas, it doesn't' seem likely to be.
 
   / Updated TV Antenna Thoughts #86  
I've always looked with skepticism on those TV antenna mileage ratings. There's just too many variables to come up with even a wild guess. Terrain, structures, weather, etc.... no way. They shouldn't be allowed to advertise those numbers without some sort of standardized testing from an independent lab and publish how they came up with the number. Best example I can give is people that live in and around the east coast of southern Lake Michigan can pick up Chicago and Milwaukee stations with ease, because its 70-100 miles across the lake, whereas they can't pick up South Bend, IN stations at only 30-40 miles away without gargantuan antennas on tall masts.
 
   / Updated TV Antenna Thoughts #87  
I just want something to pick up local TV that won't freeze every time the wind blows, or it rains, or a train, truck or airplane goes by.... well, that's not gonna happen. At least with the old way, it would fade a bit, but you could still hear the sound.

Another peeve.... most of our local stations won't broadcast 1080. They went with multiple channels at 480 to increase commercial revenue, and rarely broadcast anything in 1080. We get a lo-res picture over the air. Whereas, they'll put it on the cable at 1080. Grrr.... :mad:

:rolleyes: :laughing:
 
   / Updated TV Antenna Thoughts #88  
I just want something to pick up local TV that won't freeze every time the wind blows, or it rains, or a train, truck or airplane goes by.... well, that's not gonna happen. At least with the old way, it would fade a bit, but you could still hear the sound.

Another peeve.... most of our local stations won't broadcast 1080. They went with multiple channels at 480 to increase commercial revenue, and rarely broadcast anything in 1080. We get a lo-res picture over the air. Whereas, they'll put it on the cable at 1080. Grrr.... :mad:

:rolleyes: :laughing:

See if you had some specifications of gain in the forward lobe of your antenna, then you could take a measurement of your received signal strength, and calculate your "fade margin". This is always done in commercial installations of point to point systems. You must know your fade margin to know if a particular antenna with a particular gain is going to get the job done when conditions are not so good as your reference test. Rain and snow will attenuate your signals, but if you knew you were on the "ragged edge" or had say a 10 dB fade margin or not could help guide your choices.

Of course you can make estimates all day, and say, well, bigger is better etc. And that is true but if you KNEW what you had you could spend your money wisely. There is actual science to antennas, transmission lines (coax) and path loss. We can make actual calculations with just a LITTLE knowledge. I could teach many of you the concepts of antenna gain (never something for nothing, antennas with gain in one direction have loss in another), transmission line losses, and how the decibel scale works. in about a day. But with no specifications printed out that we can work with, we would have to do our own experiments to find these things out. So I guess we will just look at "miles" ratings and go on with life. :) Enough of my rant. But if any of you would like to learn something about antennas or related things, I will do my best to answer them. I don't have all the answers, but I can usually find them. :D
 
   / Updated TV Antenna Thoughts #89  
I have a question James, I get pretty good reception off a $25 craigslist TV antenna (looks like a 4 element Channel Master type), but I occasionally have difficulty with channel 2 and it's sidebands. They all come from "tower mountain" in Portland. Sometimes it perfect, sometimes it's so pixellated and distorted the image jams (at least with the old analog you could hear the Jeopardy questions through the snow) and becomes unwatchable.
Could that particular band be more susceptible to atmospherics, as other signals from the same area are unaffected?
AntennaWeb.jpg
 
   / Updated TV Antenna Thoughts #90  
I have a question James, I get pretty good reception off a $25 craigslist TV antenna (looks like a 4 element Channel Master type), but I occasionally have difficulty with channel 2 and it's sidebands. They all come from "tower mountain" in Portland. Sometimes it perfect, sometimes it's so pixellated and distorted the image jams (at least with the old analog you could hear the Jeopardy questions through the snow) and becomes unwatchable.
Could that particular band be more susceptible to atmospherics, as other signals from the same area are unaffected?
View attachment 540866

Are you talking about KATU-DT the ABC affiliate? as shown on the sidebar of your map? There are not very many stations actually on RF channel 2 any more, KATU-DT is on actual RF channel 43, so it is in the UHF spectrum. My first thought is that the fade margin for this station at your location is near non-existent. In other words the signal can fade (for a number of reasons) but the margin of excess signal that you have at your location is very low or none. So when a fade happens, say from tropospeheric bending or rain or snow you have no margin to make up the slight dip in signal, so you have digital drop out.

A signal strength analyzer measurement on a good day, then measure when you have drop out that would tell the tale.

Amazon.com: Solid Signal Digiair Pro ATSC TV Antenna Signal Meter Spectrum Analyzer (DIGIAIR-PRO-ATSC): Electronics
 
 
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