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IMHO using the word "Digital" is meaningless. Any good antenna for TV reception will do. I bought one at Walmart,, >$50, a few years back that works great, and I am 70 miles from the stations. Size may be a factor depending on where you are going to put it.
More Than You Ever Wanted to Know About Radio Waves
Well, for starters, there's no such thing as a "digital" antenna. Yes, I realize that there are tons of advertisements for "digital" antennas, but that's just ignorance or BS, I'm sorry to say. OK, lets take a look at this:
Wireless transmission utilizes electromagnetic radio waves. No matter what kind of "intelligence" is being transmitted, they are still radio waves. The intelligence being transmitted could be audio, video, digital information, analog information, radar, or lots of other stuff. The method of impressing information on the basic radio wave is called "modulation".
Radio waves are just one part of the "wave spectrum". The wave spectrum ranges (roughly) from the audio spectrum to the light spectrum and well beyond.
The lowest frequency band shown is "ELF", or "Extremely Low Frequency", starting at about 3hz.
Considering the radio spectrum itself, it is so wide that an antenna designed to detect relatively low frequency radio waves is useless for the detection of higher frequency radio waves.
Since you don't mention what it is that you need an antenna for, I'm going to assume that it's digital television. Now the radio spectrum is divided into different "bands", or sections, according to frequency. Analog TV previously occupied the "VHF" (Very High Frequency) band. Digital TV now occupies the "UHF" (Ultra High Frequency) band.
But it's easy to be led astray by names like VHF and UHF, because you have to understand the development of radio equipment. Early AM radio used a lower part of the radio spectrum called "Medium Wave" (MW), because that's all that the radio equipment of that time was capable of. As radio technology developed, higher parts of the radio spectrum became usable.
Compared to the AM radio band, the VHF TV band was, at the time, Very High indeed. With later technology, the UHF TV band did seem to be “ultra high”. Today, that terminology is really useless, except as historical interest. The frequencies available for use today are so high that they are now typically referred to by a rough description of their place in the radio spectrum, such as “xxx mhz (megahertz), or xxx ghz (gigahertz).
OK, finally getting down to your question: assuming that you’re needing an antenna for digital broadcast TV, you need an antenna designed for the UHF band. There are two main types available, “passive” and “active”. Active antennas are typically small set-top units using cheap and dirty wide-band amplifier circuitry. They may be useful if the available TV signal is of decent quality, with the broadcast station fairly close., but if the TV signal is marginal, they may be of little use. On the other hand, they’re fairly cheap, so you can always buy one and see what happens. I’ve seen them work when you’d think that they shouldn’t.
UHF signals are quite a bit more “line-of-sight” than lower frequency bands. That means that if there are tall buildings or geographical obstacles between the transmitter and the receiver there may well be reception difficulties.
If for whatever reason the TV signal is marginal, then a “passive” high quality outdoor directional antenna is indicated, possibly feeding into a high quality in-line amplifier located near the antenna itself. Such an antenna is typically located on a rooftop or other fairly high point, which obviously limits its use in an apartment or condo type building.
In my work as a public safety radio tech we used a lot of equipment in the UHF band, most of which was FM (frequency modulation, as differentiated from other types of modulation). There were good reasons why FM was referred to informally as “Fucking Magic”- we could never be absolutely certain what would actually work in a difficult transmitter-to-receiver transmission path. Lots of trial and error, sometimes.
Lots of good info in this conversation. As in real estate, getting good TV reception depends on location, location, and location. Location of your abode from the TV station, (distance), location of your antenna (inside or out), and location of your TV set or sets. I’m 70 miles from the TV stations with a clear shot in nice clean and dry SW air. My antenna, see link below, is located on a 12’ pole on top of my garage. I can get decent reception on a few stations without an amplifier, but I have one in line, inside the garage, see link below. From the amplifier the coax goes back up into the attic and then thru the attic and 2 signal splitters that feed 3 TV sets. The amp is needed to overcome the line loss and 3.5db loss in each splitter.
200 Miles HDTV Outdoor Yagi Antenna Amplified Digital VHF UHF TV Antenna for 4K - Walmart.com
onn. Indoor HDTV Antenna Amplifier with Signal Booster, VHF UHF 1080P 4K, Black, 100008788 - Walmart.com
@Rossby- yes sir, your info is spot on, and a good example of how receiving antennas may need to be installed with respect to height, line-of-sight to the transmitter, in-line amplifiers, and signal splitters.
One other thing to mention- the advertisements sometimes mention capabilities such as "digital", "HDTV", "4k", etc. Pure baloney. Any antenna which is capable of obtaining a UHF signal of sufficient strength will do the job. The antenna has absolutely no idea what kind of information (analog, digital, HDTV, 4k, AM, FM, or anything else) is present in the desired wireless signal.
Also be aware that antennas claiming to be great for VHF and UHF may work to some extent for both of those frequency bands, but are a design compromise, and will not work as well as an antenna designed for one or the other. There's a big difference between VHF and UHF in the signal characteristics, and if you look at an antenna designed for VHF you will note that the antenna elements are much longer than those for a UHF antenna. That's because as radio signals increase in frequency, their wavelength becomes shorter, and the design of a good antenna needs to match to that.
Note that the elements in a typical UHF "Yagi" antenna are much shorter than for the VHF equivalent:
A UHF "Yagi" antenna:
A VHF "Yagi" antenna:
And finally, here's an example of a well designed VHF/UHF antenna. It should perform well for both VHF and UHF because it has both long and short elements. Small "VHF/UHF" antennas without these types of elements are design compromises, and of dubious merit.
Yep, After getting broadband 2 years ago I ditched DirecTV but was unable to get locals over the internet using Sling’s TV service (long story). So up went an (amplified) digital antenna. Fringe area here probably 40-50 miles from transmitters.
Pointing it with a directional “rotor”, the DA worked very well in the winter months when the surrounding trees were bare, but was dysfunctional for the most part during the summer months when the leaves were out. A high hill nearby didn’t help. Finally the good folks at Hulu were able to provide locals over the internet at little additional cost. Now we’re faced with climbing a high ladder to pull the dang DA down from the highest part of our roof.
PS - A friend in another fringe area in northern Mi who doesn’t have any nearby hills has had pretty good luck using a “RV digital antenna” which he placed in his attic. Apparently without a rotor. He gets 2 or 3 networks well, but the local PBS station won’t come in for him.
@hank- please note my comments about "digital" antennas. Antennas have absolutely no idea what the signal content is... analog, digital, AM, FM, or anything else. All that they know about is the signal frequency. For example, commercial digital TV now uses the UHF signal band, and much public safety radio also uses that band. Any decent UHF antenna works fine for either.
Your problem with the seasonality is very typical- the tree leaves absorb UHF radio energy like crazy. In the winter, not so much.
@Old_Joe - Thanks for sharing your wealth of experience.
Did I error somewhere in my comment? Maybe the remark about a friend not getting PBS? Has nothing to do with frequency. Stationary mount. If he could rotate the antenna to the correct direction he likely would get that one too.
@hank- I was only referring to the use of the term "digital antenna". Not a big deal, but there's really no such thing as a "digital" antenna. The reason that I mention this is because the advertising is so misleading to anyone not familiar with the technical turf.
With respect to trees blocking a UHF signal, we have the same problem in SF. I have a high-gain UHF antenna and amplifier in the attic, pointed at the Mt Sutro TV tower, less than two miles away. Yet, because trees across the street have gotten much higher, the received signal is marginal on some channels. It's much worse when it rains, as the wet leaves really soak up the UHF signal.
When I was younger I would have erected an antenna mast on the roof and mounted the antenna up there, but at 83 my "roof days" are long gone. Fortunately we're not really interested in most of what's on TV these days anyway, and can see much of PBS via internet streaming.
@hank- Yes- maybe I should correct my previous comment to read: "Antennas have absolutely no idea what the signal content is... analog, digital, AM, FM, garbage, or anything else."
I hadn’t thought about that. Went with @Derf’s wording. But the “signal” is much different, even if the antenna isn’t.
BTW - as a kid I got ahold of an old radio capable of tuning to multiple frequencies. I think it was from some “Grannie’s” home after she passed on. Anyway, I strung a piece of wire from the upstairs of our Michigan house to the garage some 40-50 feet away to serve as a antenna. Wow! using the short wave frequency I got a crystal clear signal from Radio Havana nights. LOL. An eye opener. Being back in the 60s you can imagine the propaganda directed at us “imperialist pigs.” But, it was a lot of fun and I didn’t turn “red” as a result.
@hank- Yes indeed, I did similar horsing around as a kid. BTW, as I mentioned above someplace, the higher you go in frequency the "shorter" the wavelength. That's why anything much above the AM broadcast band was called "shortwave". With today's use of frequencies so high that they are near the Infrared Light spectrum (take a look at the chart way up near the top of this thread) those old "shortwave" frequencies are, by comparison, really very long.
Yuppers. Trying to get my head around it. Shorter wavelengths travel further. Right? But tuning to one was much harder as I recall. Very sensitive.
BTW - Subscribed to a year of Magellan for something like $60. Not bad. Lots of science, aviation & astronomy, but nothing very deep thus far. Of course, PBS is excellent.
Actually, it's a bit more complex than that, because various wavelengths act differently under different conditions. Generally speaking, the longer wavelengths, say up through the VHF band, tend to travel further, because they can bounce of of the ionosphere, as well as having a strong "ground wave", which allows them to follow the earth contour to a degree, and also tend to not be blocked as much by buildings. For example, many highway patrols use Low Band and VHF because of those features, while local police departments tend to use UHF because it is more localized and thus interferes less with neighboring departments. The assignment of Public Safety frequencies can become very contentious, political, and difficult between various jurisdictions, because of the limited number of frequencies available for these services.
As you go higher in frequency the radio waves tend to essentially travel more and more in line-of-sight and have more difficulty in penetrating structures. This becomes a real problem in public safety, where it's frequently necessary to communicate with police and fire personnel inside buildings.
The line-of-sight characteristic can be very useful, though. Microwaves can be very narrowly focused by special antennas, allowing them to be used to transmit signals between two specific locations. Those antennas have the round reflector dishes which you see on so many radio installations. This is also very useful in radar work.
@hank- Not to hijack this thread, but take a look at the pics over on your "Don't like the war" thread. Some of the Russian mechanized units are taking a real beating.
You know, I sometimes wonder when: • an MFO poster asks a question- • people spend a fair amount of time and energy trying to help... • and the MFO poster is never heard from again in the thread that they started.
I really don't understand stuff like this. How hard is it to simply say "thanks"?
At Old_Joe : It seems to me shortly after I asked my question & received two or three replies, a thanks for the info to you & Rossby & possible hank. Looking back I see nothing. So I either didn't hit the send button or it disappeared. So thanks for all the info & time that posters put into this antenna question. I've put the antenna question on hold & looking into see if latest purchased TV can be used wireless instead of hardwired to router. Called LG & their "hot line" was able to reply that Dongle would work along with mirroring. I need to check with Teckie friend to explain mirroring & make the cord cutting complete. Dish bill went up 25% so they'll get the boot shortly. Thanks for your time & to bring this forth, Derf
Wireless? Dongle? Mirroring? Time to put my RCA Tube Manual in my tube caddie and leave. Need to spend some time learning about this new thing called a transistor.
@Rossby : If interested in cutting the cord, checkout Consumer Reports, Oct.. I believe they had article on the same last year about this time. As for the transistor , it's been around quite awhile . I'm still on antenna hold as far as a backup if internet should go down for a time. Have a good day, Derf
@Rossby- Hey, I not only still have my faithful RCA Receiving Tube Manual but also my RCA Transistor Manual. Actually, I kept two of the tube manuals- the older one is the 1954 manual (price: 60¢) that as a kid I used so heavily that the binding disintegrated- it's held together by machine screws, washers and nuts.
Also retained in my small technical library is a much used copy of the "Most-Often-Needed 1926-1938 Radio Diagrams", which I often used to repair ancient radios. Looking through the index, there's a panoply of radio manufacturers that almost no one now remembers. Of course there's RCA, GE, and other big names, but also Arvin, Atwater Kent, Crosley, Delco, Emerson, Graybar, Majestic, Montgomery Ward, Philco, Sears Roebuck, Westinghouse and of course Zenith, just to name a few.
I taught myself basic electronics from the Theory of Operation and Circuits sections in those RCA manuals. In the 1980s, at my final job as a SF Public Safety radio tech, I was of course one of the older guys, and out of some 15 techs there were only two of us who actually knew all about "tubes". And a good thing, too, because even as late as 2005 SF still had a few ancient Low Band transmitters with vacuum tubes in the finals.
Comments
Well, for starters, there's no such thing as a "digital" antenna. Yes, I realize that there are tons of advertisements for "digital" antennas, but that's just ignorance or BS, I'm sorry to say. OK, lets take a look at this:
Wireless transmission utilizes electromagnetic radio waves. No matter what kind of "intelligence" is being transmitted, they are still radio waves. The intelligence being transmitted could be audio, video, digital information, analog information, radar, or lots of other stuff. The method of impressing information on the basic radio wave is called "modulation".
Radio waves are just one part of the "wave spectrum". The wave spectrum ranges (roughly) from the audio spectrum to the light spectrum and well beyond.
The lowest frequency band shown is "ELF", or "Extremely Low Frequency", starting at about 3hz.
Considering the radio spectrum itself, it is so wide that an antenna designed to detect relatively low frequency radio waves is useless for the detection of higher frequency radio waves.
Since you don't mention what it is that you need an antenna for, I'm going to assume that it's digital television. Now the radio spectrum is divided into different "bands", or sections, according to frequency. Analog TV previously occupied the "VHF" (Very High Frequency) band. Digital TV now occupies the "UHF" (Ultra High Frequency) band.
But it's easy to be led astray by names like VHF and UHF, because you have to understand the development of radio equipment. Early AM radio used a lower part of the radio spectrum called "Medium Wave" (MW), because that's all that the radio equipment of that time was capable of. As radio technology developed, higher parts of the radio spectrum became usable.
Compared to the AM radio band, the VHF TV band was, at the time, Very High indeed. With later technology, the UHF TV band did seem to be “ultra high”. Today, that terminology is really useless, except as historical interest. The frequencies available for use today are so high that they are now typically referred to by a rough description of their place in the radio spectrum, such as “xxx mhz (megahertz), or xxx ghz (gigahertz).
OK, finally getting down to your question: assuming that you’re needing an antenna for digital broadcast TV, you need an antenna designed for the UHF band. There are two main types available, “passive” and “active”. Active antennas are typically small set-top units using cheap and dirty wide-band amplifier circuitry. They may be useful if the available TV signal is of decent quality, with the broadcast station fairly close., but if the TV signal is marginal, they may be of little use. On the other hand, they’re fairly cheap, so you can always buy one and see what happens. I’ve seen them work when you’d think that they shouldn’t.
UHF signals are quite a bit more “line-of-sight” than lower frequency bands. That means that if there are tall buildings or geographical obstacles between the transmitter and the receiver there may well be reception difficulties.
If for whatever reason the TV signal is marginal, then a “passive” high quality outdoor directional antenna is indicated, possibly feeding into a high quality in-line amplifier located near the antenna itself. Such an antenna is typically located on a rooftop or other fairly high point, which obviously limits its use in an apartment or condo type building.
In my work as a public safety radio tech we used a lot of equipment in the UHF band, most of which was FM (frequency modulation, as differentiated from other types of modulation). There were good reasons why FM was referred to informally as “Fucking Magic”- we could never be absolutely certain what would actually work in a difficult transmitter-to-receiver transmission path. Lots of trial and error, sometimes.
Here's a few typical examples from Amazon, in increasing order of performance and price:
• TV Antenna Indoor, "Digital" Amplified Indoor HDTV Antenna (Similar to the antenna mentioned by Rossby)
• Compact Outdoor or Attic Yagi TV Antenna
• Outdoor Digital Amplified HDTV Antenna
As in real estate, getting good TV reception depends on location, location, and location. Location of your abode from the TV station, (distance), location of your antenna (inside or out), and location of your TV set or sets.
I’m 70 miles from the TV stations with a clear shot in nice clean and dry SW air. My antenna, see link below, is located on a 12’ pole on top of my garage.
I can get decent reception on a few stations without an amplifier, but I have one in line, inside the garage, see link below.
From the amplifier the coax goes back up into the attic and then thru the attic and 2 signal splitters that feed 3 TV sets. The amp is needed to overcome the line loss and 3.5db loss in each splitter.
200 Miles HDTV Outdoor Yagi Antenna Amplified Digital VHF UHF TV Antenna for 4K - Walmart.com
onn. Indoor HDTV Antenna Amplifier with Signal Booster, VHF UHF 1080P 4K, Black, 100008788 - Walmart.com
One other thing to mention- the advertisements sometimes mention capabilities such as "digital", "HDTV", "4k", etc. Pure baloney. Any antenna which is capable of obtaining a UHF signal of sufficient strength will do the job. The antenna has absolutely no idea what kind of information (analog, digital, HDTV, 4k, AM, FM, or anything else) is present in the desired wireless signal.
Also be aware that antennas claiming to be great for VHF and UHF may work to some extent for both of those frequency bands, but are a design compromise, and will not work as well as an antenna designed for one or the other. There's a big difference between VHF and UHF in the signal characteristics, and if you look at an antenna designed for VHF you will note that the antenna elements are much longer than those for a UHF antenna. That's because as radio signals increase in frequency, their wavelength becomes shorter, and the design of a good antenna needs to match to that.
Note that the elements in a typical UHF "Yagi" antenna are much shorter than for the VHF equivalent:
A UHF "Yagi" antenna:
A VHF "Yagi" antenna:
And finally, here's an example of a well designed VHF/UHF antenna. It should perform well for both VHF and UHF because it has both long and short elements. Small "VHF/UHF" antennas without these types of elements are design compromises, and of dubious merit.
.
Pointing it with a directional “rotor”, the DA worked very well in the winter months when the surrounding trees were bare, but was dysfunctional for the most part during the summer months when the leaves were out. A high hill nearby didn’t help. Finally the good folks at Hulu were able to provide locals over the internet at little additional cost. Now we’re faced with climbing a high ladder to pull the dang DA down from the highest part of our roof.
PS - A friend in another fringe area in northern Mi who doesn’t have any nearby hills has had pretty good luck using a “RV digital antenna” which he placed in his attic. Apparently without a rotor. He gets 2 or 3 networks well, but the local PBS station won’t come in for him.
Your problem with the seasonality is very typical- the tree leaves absorb UHF radio energy like crazy. In the winter, not so much.
Did I error somewhere in my comment? Maybe the remark about a friend not getting PBS? Has nothing to do with frequency. Stationary mount. If he could rotate the antenna to the correct direction he likely would get that one too.
With respect to trees blocking a UHF signal, we have the same problem in SF. I have a high-gain UHF antenna and amplifier in the attic, pointed at the Mt Sutro TV tower, less than two miles away. Yet, because trees across the street have gotten much higher, the received signal is marginal on some channels. It's much worse when it rains, as the wet leaves really soak up the UHF signal.
When I was younger I would have erected an antenna mast on the roof and mounted the antenna up there, but at 83 my "roof days" are long gone. Fortunately we're not really interested in most of what's on TV these days anyway, and can see much of PBS via internet streaming.
Got it. Thanks
Yes - An incredibly wasteful medium.
"Antennas have absolutely no idea what the signal content is... analog, digital, AM, FM, garbage, or anything else."
I hadn’t thought about that. Went with @Derf’s wording. But the “signal” is much different, even if the antenna isn’t.
BTW - as a kid I got ahold of an old radio capable of tuning to multiple frequencies. I think it was from some “Grannie’s” home after she passed on. Anyway, I strung a piece of wire from the upstairs of our Michigan house to the garage some 40-50 feet away to serve as a antenna. Wow! using the short wave frequency I got a crystal clear signal from Radio Havana nights. LOL. An eye opener. Being back in the 60s you can imagine the propaganda directed at us “imperialist pigs.” But, it was a lot of fun and I didn’t turn “red” as a result.
BTW - Subscribed to a year of Magellan for something like $60. Not bad. Lots of science, aviation & astronomy, but nothing very deep thus far. Of course, PBS is excellent.
As you go higher in frequency the radio waves tend to essentially travel more and more in line-of-sight and have more difficulty in penetrating structures. This becomes a real problem in public safety, where it's frequently necessary to communicate with police and fire personnel inside buildings.
The line-of-sight characteristic can be very useful, though. Microwaves can be very narrowly focused by special antennas, allowing them to be used to transmit signals between two specific locations. Those antennas have the round reflector dishes which you see on so many radio installations. This is also very useful in radar work.
• an MFO poster asks a question-
• people spend a fair amount of time and energy trying to help...
• and the MFO poster is never heard from again in the thread that they started.
I really don't understand stuff like this. How hard is it to simply say "thanks"?
So thanks for all the info & time that posters put into this antenna question.
I've put the antenna question on hold & looking into see if latest purchased TV can be used wireless instead of hardwired to router. Called LG & their "hot line" was able to reply that Dongle would work along with mirroring. I need to check with Teckie friend to explain mirroring & make the cord cutting complete.
Dish bill went up 25% so they'll get the boot shortly.
Thanks for your time & to bring this forth, Derf
Time to put my RCA Tube Manual in my tube caddie and leave.
Need to spend some time learning about this new thing called a transistor.
Have a good day, Derf
Also retained in my small technical library is a much used copy of the "Most-Often-Needed 1926-1938 Radio Diagrams", which I often used to repair ancient radios. Looking through the index, there's a panoply of radio manufacturers that almost no one now remembers. Of course there's RCA, GE, and other big names, but also Arvin, Atwater Kent, Crosley, Delco, Emerson, Graybar, Majestic, Montgomery Ward, Philco, Sears Roebuck, Westinghouse and of course Zenith, just to name a few.
I taught myself basic electronics from the Theory of Operation and Circuits sections in those RCA manuals. In the 1980s, at my final job as a SF Public Safety radio tech, I was of course one of the older guys, and out of some 15 techs there were only two of us who actually knew all about "tubes". And a good thing, too, because even as late as 2005 SF still had a few ancient Low Band transmitters with vacuum tubes in the finals.
Thanks for jogging my memory.
OJ