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alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1

Hopeless or possible? HDTV OTA

I'd like to catch some HDTV (or at least DTV) channels over the air from transmitters 85 miles away.

According to tvfool.com, there's a bunch of stations within the same spot with those stats:

85 miles distance (Line of sight)
25 nm(dB)
-65 Pwr(dBm)

I'd get a Channel Master CM 3671 . However, for the UHF channels (All the channels in question are UHF) it is said to only go as far as 60 miles. I can't find anything more powerful.

The antenna would be placed 30 feet above ground.
There's a tree in the LOS about 30 feet away.
The cable to connect the tv to it would be a good 40 feet, so I guess I'd need an amplifier.

I'd rather not spend the $$$$ on such an antenna if it's unlikely.



cdru
Go Colts
Premium,MVM
join:2003-05-14
Fort Wayne, IN
kudos:7

said by alkizmo:

85 miles distance (Line of sight)
...
The antenna would be placed 30 feet above ground.

An antenna 30' off the ground has LOS to an antenna 85 miles away if the far antenna is approximately 3000' tall. Since the tallest structure ever built (Burj Khalifa) is about 2722', and the tallest antenna (KVLY-TV mast) is 2063', you are SOL for a direct LOS signal. With the right equipment, weather, and atmosphere conditions, you might get favorable propagation, but your signal quality will probably be poor.

Pher9999

join:2011-07-06
Carmel, NY
reply to alkizmo

I had good luck with the smaller antenna from Monoprice. »www.monoprice.com/products/produ···format=2 or you can make your own out of Copper wires and cable. »www.tvantennaplans.com/

Where we live now is in a valley so no antenna will work. Barely get Cell reception.



TheTechGuru

join:2004-03-25
TEXAS
kudos:2
Reviews:
·HughesNet Satell..
·WesTex Connect
reply to alkizmo

That antenna is a waste if all you need is UHF.

Not to mention is has VHF-LO elements which are not even used anymore.

You need a UHF only or a UHF with VHF-HI only.

Here is a good UHF only.

»www.solidsignal.com/pview.asp?mc···48001910

and here is a good UHF with VHF-HI

»www.solidsignal.com/pview.asp?mc···nas&sku=

Ether one, install a inline amp at the antenna.
--
CompTIA Network+ Certified



PSWired

join:2006-03-26
Annapolis, MD
reply to cdru

Don't forget to take terrain into account. Many TV towers are on top of mountains.



leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET
reply to alkizmo

That is the wrong antenna for long distance UHF only stations. Most of the receiving elements on that antenna are for VHF which won't do you any good at all. The fact that is also doubles as an FM radio antenna might even be harmful for your purpose.

What you need is a multi-element directional UHF antenna such as the 8 element Channel Master CM-4228HD or Winegard HD-8800.

Those multi-element antennas (if properly aligned) combine the weak signal from distant transmitters.
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TheTechGuru

join:2004-03-25
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2 edits

1 recommendation

said by leibold:

That is the wrong antenna for long distance UHF only stations. Most of the receiving elements on that antenna are for VHF which won't do you any good at all. The fact that is also doubles as an FM radio antenna might even be harmful for your purpose.

What you need is a multi-element directional UHF antenna such as the 8 element Channel Master CM-4228HD or Winegard HD-8800.

Yep, like the first one I posted: »www.solidsignal.com/pview.asp?mc···48001910

It may look small in the pic, but it's 7.75 feet long. ALL UHF ELEMENTS.
--
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alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1

2 edits
reply to leibold

said by cdru:

An antenna 30' off the ground has LOS to an antenna 85 miles away if the far antenna is approximately 3000' tall.

Considering the direction of the stations, as per tvfool.com, it seems to point at the adirondaks. I'm betting the transmitters are on top of the mountains. The website does say I have LOS and it does mention that other closer stations aren't in LOS, so I think they are correct.

edit: Yup, mountain top (all of them). Check these coordinates on google maps 44.525607 -72.815679 (according to some google API, that mountain top is 3000 feet up )

said by leibold:

That is the wrong antenna for long distance UHF only stations. Most of the receiving elements on that antenna are for VHF which won't do you any good at all. The fact that is also doubles as an FM radio antenna might even be harmful for your purpose.

What you need is a multi-element directional UHF antenna such as the 8 element Channel Master CM-4228HD or Winegard HD-8800.

Those multi-element antennas (if properly aligned) combine the weak signal from distant transmitters.

1 - There are a couple of local stations that are VHF-Hi that i'd like to get (I'd get a motor to orient it if I watch those channels). Though I guess i could get a second smaller cheaper antenna for the local stations.

2 - The far away stations are all in the exact same azimuth, wouldn't a yagi get more distance if perfectly aligned?


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
reply to alkizmo

»www.avsforum.com/f/?s=

85 miles is a stretch. I'm doing 47 mostly over water with a Channel Master 4228 and Channel Master Amp.



alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1

said by Jack_in_VA:

»www.avsforum.com/f/?s=

85 miles is a stretch. I'm doing 47 mostly over water with a Channel Master 4228 and Channel Master Amp.

That forum is blocked at work.
Plus I love you guys!

Did you check on tvfool.com for your location and what's the status of the towers around you? There are some towers that are 50 miles from me, but marked as "red" with no LOS because of their location/elevation/power. Could be a mountain in the way, they aren't very high, they have a weak transmitter, etc etc.


leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
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reply to alkizmo

The purpose of an antenna is not to "get distance". Its purpose is to get as much as possible of the transmitted signal while ignoring as much noise as possible.

I'm not an HF expert but I very much doubt that a single yagi antenna will get anywhere near the same amount of useful signal as these multi-element antennas.

The yagi while directional isn't as sensitive to direction and a slight deviation from optimal will probably still get you a good signal (provided it is strong or close). However in order to get the same gain as a multi-element UHF antenna you would have to combine several yagi antennas. This is not easy but it is possible and if you search on the Internet (look for vertical and horizontal stacking of antennas) there are reports from people who have done that. If you do that you have the same gains but also the same requirement for proper alignment as with a multi-element antenna.

The multi-element antenna is more challenging. Any deviation from the correct alignment will cause the signal to arrive phase shifted on some of the dipoles. That phase shift will cause the signals to partially cancel each other out (instead of the signals being combined to a much stronger signal).
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ke4pym
Premium
join:2004-07-24
Charlotte, NC
Reviews:
·VOIPO
·ooma
·Verizon Broadban..
·Northland Cable ..
·Time Warner Cable
reply to alkizmo

I think you can probably bring that station down with the a-fore-mentioned high gain antenna TheTechGuru posted.

Couple it with a proper in-line pre-amplifier (this would be a good one to start with - »www.solidsignal.com/pview.asp?mc···79001809 ) near the antenna and it'll be a wicked installation.

Remember, amplifiers amplify noise along with signal. So, if you have a crappy signal at the output of your antenna, that crappy signal is going to be worse after going through the amp.

Consider using quad-shield coax between your antenna, pre-amp and then your distribution block.

BUT - if you try to use this combination for any of your closer stations, you're going to overload the front end of your tuner section and probably won't have much to work with to get a station (too much signal is just as bad as not enough).

@Jack - Water and land have very different signal propagation characteristics - the two really can't be compared.


ncbill
Premium
join:2007-01-23
Winston Salem, NC
reply to alkizmo

I can usually get WSOC, 60 miles away, with nothing more than a 2-bay UHF antenna, hanging off the entertainment center, pointed out the window, coupled with a high-gain preamp (signal split to two HDTVs).

said by alkizmo:

said by Jack_in_VA:

»www.avsforum.com/f/?s=

85 miles is a stretch. I'm doing 47 mostly over water with a Channel Master 4228 and Channel Master Amp.

That forum is blocked at work.
Plus I love you guys!

Did you check on tvfool.com for your location and what's the status of the towers around you? There are some towers that are 50 miles from me, but marked as "red" with no LOS because of their location/elevation/power. Could be a mountain in the way, they aren't very high, they have a weak transmitter, etc etc.



fifty nine

join:2002-09-25
Sussex, NJ
kudos:2
reply to alkizmo

I have a large TV antenna stack.

2xCM4228A phased array (16 element bow tie array), 1 x Winegard YA1710 for VHF.

Added to that I have a low noise GaAsFET preamp.

I get philly stations 90 miles away and NYC 48 miles away no problem.



alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
reply to ke4pym

said by ke4pym:

I think you can probably bring that station down with the a-fore-mentioned high gain antenna TheTechGuru posted.

BUT - if you try to use this combination for any of your closer stations, you're going to overload the front end of your tuner section and probably won't have much to work with to get a station (too much signal is just as bad as not enough).

Well, from all the info from you guys, what I might do is buy the 91XG for the far away stations, and a cheaper smaller UHF/VHF antenna for the local stations. They are basicall 90 degrees apart in direction, so instead of buying a motor, I'd just install two antennas pointed in two directions, and the signal strenght issue would be resolved.

I'm going to shop for where to buy them at the best price, and start reading up on baluns, pre-amps, and combining the two antennas.


fifty nine

join:2002-09-25
Sussex, NJ
kudos:2
reply to alkizmo

said by alkizmo:

The antenna would be placed 30 feet above ground.
There's a tree in the LOS about 30 feet away.
The cable to connect the tv to it would be a good 40 feet, so I guess I'd need an amplifier.

I'd rather not spend the $$$$ on such an antenna if it's unlikely.

Copy/paste your TV Fool report URL. It won't show your address or personal data.

The tree is a problem. Try to get out of its way (or use a chainsaw?) Not so much for attenuation but because all of those leaves will cause multipath.

30 feet will likely be too low. I have my antenna at 70 feet to get a barely acceptable signals from 90ft.

At 85 miles it is probably not going to be LOS. In fact I'm sure of it.

ke4pym
Premium
join:2004-07-24
Charlotte, NC
Reviews:
·VOIPO
·ooma
·Verizon Broadban..
·Northland Cable ..
·Time Warner Cable
reply to alkizmo

If you wanna get really freaky:

Find a preamp with 300-ohm input. Then get some of the old school twin lead cable to run from the antenna to the pre-amp. Skip the balun all together. Switch to 75-ohm coax after the preamp on the mast.

Twin lead has some of the best signal interference rejection out there.

You *have* to use stand offs though. The cable can't come anywhere near your mast.

Careful with the extra antennas. Those can induce multipath issues. But most modern tuners are pretty well equipped to handle that kind of thing now.



alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
reply to fifty nine

»www.tvfool.com/?option=com_wrapp···076ecc4a

The target stations are the ones in yellow @ 143 degrees.
The other ones above at 91 degrees are very local, so no issues with a smaller antenna.

Tree removal isn't really something I'd do just to get free OTA. I'm not that desperate to get OTA (I was willing to just give up)



Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
reply to ke4pym

said by ke4pym:

@Jack - Water and land have very different signal propagation characteristics - the two really can't be compared.

Thanks but I didn't ask for a critique of my statement. I was just clarifying how I am presently using my setup which is only backup as I use Directv for my primary source. I know the performance very well is different land vs water.

The Channel Master CM4228 coupled with the Channel Master RM7777 RF Amp is a great combo. Good quality amps don't overload the tuners so that is a non-issue using a good amp and quality receiver.


TheTechGuru

join:2004-03-25
TEXAS
kudos:2
Reviews:
·HughesNet Satell..
·WesTex Connect
reply to ke4pym

said by ke4pym:

If you wanna get really freaky:

Find a preamp with 300-ohm input. Then get some of the old school twin lead cable to run from the antenna to the pre-amp. Skip the balun all together. Switch to 75-ohm coax after the preamp on the mast.

Twin lead has some of the best signal interference rejection out there.

You *have* to use stand offs though. The cable can't come anywhere near your mast.

Careful with the extra antennas. Those can induce multipath issues. But most modern tuners are pretty well equipped to handle that kind of thing now.

Meh, I prefer a inline line powered preamp screwed right into the matching transformer on the antenna.
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leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET
reply to alkizmo

That is almost exactly what I have done (two antennas at 90 degree angle to each other). Ideally those antennas should be spaced 2 * wavelength apart to prevent them from effecting each other in unpredictable ways.

That is usually not a problem for the short wavelength of UHF but the wavelength for VHF band III (VHF-Hi) is up to 1.7 meters (VHF band I or VHF-Lo would be up to 6 meters!).

I solved this by having one antenna on a roof antenna mast while the other antenna is on a chimney mount.

Don't sweat it too much if you can't separate them that far, just know that for best results you maintain some distance between them.

The other advise I read while planning my setup was to keep the length of the antenna cable from each antenna to the splitter/combiner exactly the same length (to keep signals arriving on both antennas in phase).
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Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
reply to alkizmo

said by alkizmo:

Well, from all the info from you guys, what I might do is buy the 91XG for the far away stations, and a cheaper smaller UHF/VHF antenna for the local stations. They are basicall 90 degrees apart in direction, so instead of buying a motor, I'd just install two antennas pointed in two directions, and the signal strenght issue would be resolved.

I'm going to shop for where to buy them at the best price, and start reading up on baluns, pre-amps, and combining the two antennas.

With the changeover most stations are on UHF so a VHF antenna will do nothing for you. We have one station here that reverted to their original VHF Channel 13 but being it's so high I can receive it with my UHF antenna though the signal level is much lower than the other UHF channels.

Don't waste your money. Just get a good UHF antenna and amp.

Check these out and shop for price. Solid Signal has them or at least they did when I bought mine from them.


Channel Master 4228HD 8-bay HDTV/UHF TV Antenna (4228-HD)

Or better here:

»www.channelmasterstore.com/Outdo···s/20.htm


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
reply to ke4pym

said by ke4pym:

If you wanna get really freaky:

Find a preamp with 300-ohm input. Then get some of the old school twin lead cable to run from the antenna to the pre-amp. Skip the balun all together. Switch to 75-ohm coax after the preamp on the mast.

Twin lead has some of the best signal interference rejection out there.

You *have* to use stand offs though. The cable can't come anywhere near your mast.

Careful with the extra antennas. Those can induce multipath issues. But most modern tuners are pretty well equipped to handle that kind of thing now.

Why would someone want to revert back to 1950's technology with 300 ohm twinlead? You'll have ghosting and multi-path freezes and blocking. The preamp goes right at the antenna so there's really no need for twinlead.


leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET
reply to Jack_in_VA

I have the CM 4224 (basically half of the CM 4228) and can recommend it but the antenna linked to by TheTechGuru See Profile has 4dB more gain then either the CM 4228 or the HD-8800. If those specs are correct it would be the better choice.
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Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Reviews:
·Millenicom
reply to leibold

said by leibold:

That is almost exactly what I have done (two antennas at 90 degree angle to each other). Ideally those antennas should be spaced 2 * wavelength apart to prevent them from effecting each other in unpredictable ways.

That is usually not a problem for the short wavelength of UHF but the wavelength for VHF band III (VHF-Hi) is up to 1.7 meters (VHF band I or VHF-Lo would be up to 6 meters!).

I solved this by having one antenna on a roof antenna mast while the other antenna is on a chimney mount.

Don't sweat it too much if you can't separate them that far, just know that for best results you maintain some distance between them.

The other advise I read while planning my setup was to keep the length of the antenna cable from each antenna to the splitter/combiner exactly the same length (to keep signals arriving on both antennas in phase).

What are you receiving on VHF? We have one channel that reverted to VHF-13 after the changeover at the request of the station and FCC to avert interference with another station. Otherwise everything is UHF.


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
reply to leibold

Ok let's focus on getting to the 85 miles away stations on UHF only. I can deal with the local stations with a second smaller antenna placed away from the big one.

I'm still torn here on whether I go directional (XG91) or multi-element (HD 4228).

They are both available locally to me at the same price (100$).

TechGuru recommended directionals yagis.
Leibold recommended multi elements.
Then everyone else is on either camps.

What do?

Notes: Tree will not come down (if it makes a difference for either antenna).



fartness
computersoc dot com
Premium
join:2003-03-25
Look Outside

Buy both and return one?



leibold
Premium,MVM
join:2002-07-09
Sunnyvale, CA
kudos:10
Reviews:
·SONIC.NET

1 edit
reply to Jack_in_VA

said by Jack_in_VA:

What are you receiving on VHF?

KGO (ABC) and KNTV (NBC) are transmitting in VHF band III. Last time I checked there was even a pending application to transmit on channel 6 (VHF band I) but I don't see that any longer.

The furthest away station that I'm receiving is KRCB (73 miles) on UHF. All other stations are half that distance or closer.

Edit: I should probably add that neither of my two antennas has a pre-amp. I do however use a cheap amplified splitter inside the home.
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alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
reply to fartness

said by fartness:

Buy both and return one?

One of them is from a store with no return unless defective (exchange only) policy.

Also I'd rather not be playing on my roof switching back and forth between two antennas :P
AND, the tree doesn't have leaves anymore at this time of the year, so I wouldn't be able to test how they behave differently in summer time.


fartness
computersoc dot com
Premium
join:2003-03-25
Look Outside

Are you trying to pick up a station from Ottawa? Is it on satellite or cable?