How far can HD signal travel if the antenna is high? Sports from out of town markets? - AVS Forum
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post #1 of 22 Old 12-05-2009, 12:23 PM - Thread Starter
 
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Is it possible to get HD stations from cities 100 or 200 miles away? Is it possible to get this signal to lock consistantly. For example, for the people living in the Chicago area, is it possible to lock a HD signal from Milwuakee (90 miles away) or Indy (180 miles away)? In addition to the Bears, Cubs, Sox, and Bulls, this would give Chicago the Bucks, Packers, Colts, Brewers, and Pacers games.

I am willing to buy 2 additional antennas and point them in the correct directions. My questions are, how high would these antennas need to be? Is there any correlation betwen height of the antenna and the distance of the signal recieved?

What is the farthest a HD signal can travel and lock consistantly assuming the antenna is big enough and high enough?
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post #2 of 22 Old 12-05-2009, 12:42 PM
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The average figure based on curvature of the earth is 60 miles. There are circumstances such as the height of the transmission tower, terrain, etc that can extend that some. 90 miles is probably pushing it, 180 wouldn't really be possible.

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post #3 of 22 Old 12-05-2009, 05:32 PM
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I get stations with transmissions of 290 to 1000KW locking at 71 miles and 2-edge.

I'm using a 55' tower (trying to get it to 65'+) with a Channel Master CM3020 antenna & pre-amp (Hi-Gain). This all feeds a Channel Master 3414 for distribution.
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post #4 of 22 Old 12-05-2009, 06:07 PM
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Google "radio horizon" for starters.
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post #5 of 22 Old 12-05-2009, 07:43 PM - Thread Starter
 
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Quote:
Originally Posted by systems2000 View Post

I get stations with transmissions of 290 to 1000KW locking at 71 miles and 2-edge.

I'm using a 55' tower (trying to get it to 65'+) with a Channel Master CM3020 antenna & pre-amp (Hi-Gain). This all feeds a Channel Master 3414 for distribution.

How many feet high was the antenna before you raised it to 55'? What was your signal stregnth on the 71 mile stations before you went to 55' and what is your signal stregnth now at 55'? I'm very interested to know what your signal stregnth will go to when you raise the antenna to 65'.
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post #6 of 22 Old 12-05-2009, 07:48 PM
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With an AntennasDirect 91XG for UHF and Winegard YA-1713 for VHF, about 25 feet up, with a Channel Master 7777 pre-amp, I get reliable reception for two groups of stations at 68 and 72 miles, with power levels ranging from about 200 to 1000 kW for UHF, and 40-50 kW for VHF. Some of them get flaky maybe one or two nights a month because of weather conditions.

I also have trees scattered around me in the neighborhood, but not enough to make a "solid" wall.

Beyond 72 miles, reception is intermittent at best, and strongly dependent on the weather, except for one station 83 miles away whose transmitter is on top of a 6000' mountain which just barely gives me line-of-sight to it.
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post #7 of 22 Old 12-05-2009, 08:09 PM
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Quote:
Originally Posted by Awesomeness View Post

Is it possible to get HD stations from cities 100 or 200 miles away? Is it possible to get this signal to lock consistantly. For example, for the people living in the Chicago area, is it possible to lock a HD signal from Milwuakee (90 miles away) or Indy (180 miles away)? In addition to the Bears, Cubs, Sox, and Bulls, this would give Chicago the Bucks, Packers, Colts, Brewers, and Pacers games.

I am willing to buy 2 additional antennas and point them in the correct directions. My questions are, how high would these antennas need to be? Is there any correlation betwen height of the antenna and the distance of the signal recieved?

What is the farthest a HD signal can travel and lock consistantly assuming the antenna is big enough and high enough?

The answer is that you can't receive a station whose carrier-to-noise ratio is about 15-16 dB. The signal has to be 15-16 dB above the noise level at the antenna input.

You also can't receive a distant channel if there is a station on the same channel in your local market.

You didn't say where you lived, but for the examples you gave, Chicago and Indy share some channels. Chicago and Milwaukee are closer together and don't share any channels.

The answer, like for so many things, is "It depends."
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post #8 of 22 Old 12-05-2009, 08:31 PM
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Consistent and dependable DTV reception is mostly about line-of-sight between the transmit antenna and the receive antenna. As most DXers would tell you, it's all about location, location, location. A friend in western Illinois, who lives out in a very rural area overlooking mostly corn and soybean fields, receives St. Louis DTV stations approx. 80-90% of the time @ 99-104 miles using a very modest Yagi-style UHF antenna just 18 ft. AGL. This is the same distance from my location to the TV towers in Cincinnati and I have to have tropo scatter/enhancement in order to receive them from my suburban location in Indy with stacked Yagi antennas @ 43 ft. AGL.

With the help of Mother Nature from time to time, tropospheric ducting will allow VHF and/or UHF stations to travel hundreds of miles. A few weeks ago this type of propagation allowed me to receive UHF DTV stations from Alabama and Georgia, including WTVY-DT-36, Dothan, AL @ 623 miles.

On average, due to lack of LOS reception plus co-channel interference due to minimum spacing between stations, daily reception is usually going to be limited to 60-75 miles, but of course, YMMV.

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post #9 of 22 Old 12-06-2009, 08:33 AM
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Quote:
Originally Posted by Awesomeness View Post

How many feet high was the antenna before you raised it to 55'? What was your signal stregnth on the 71 mile stations before you went to 55' and what is your signal stregnth now at 55'? I'm very interested to know what your signal stregnth will go to when you raise the antenna to 65'.

Why not visit www.tvfool.com and give us a copy of your results so that we can determine if any other stations are possible?

For example, here is my list. http://www.tvfool.com/?option=com_wr...7721a9dc049687

I do not receive WFXI, WILM LD, WRAL, WRAZ or WTVD. I do however receive WRDC, WNCN, and WLFL from the same area at 90 miles with a WInegard HD 8800. It just depends on how you aim and the height. I get all the other channels all the time above those, at 62 miles for WWAY, WECT and WSFX
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post #10 of 22 Old 12-06-2009, 08:40 AM
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I live in hilly east central Wisconsin, between the Green Bay and Wausau markets. My reception setup contains an Antennacraft MXU59 UHF antenna in my attic and an outdoor tower. The tower has an FM whip dipole at the top. Under the dipole, 43' above ground level, is an Antennas Direct 91XG UHF antenna pointed East at Green Bay towers 38 miles away. I need the height because I am on the back side of a tall hill. At 40' AGL and pointed north, I have a Blonder tongue channel 16 UHF antenna pointed north to Rhinelander, 92 miles away. I receive NBC 12 reliably. This antenna is mounted in such a way that it is physically about 6' from the nearest point of any other antenna. I am considering stacking a second BT antenna for better reliability in bad weather. Bad weather is a killer at long distance, although with the single antenna and this distance, I still get about 98% reliability.

Under the BT, back on the main tower, is a Funke psp.1922 VHF highbander mounted 37' AGL and pointed at Green Bay to receive Fox 11 over the hill. I then have a side mount mast 4' off the tower where I have a second Funke VHF highbander pointed NW towards Wausau where I receive channels 7 and 9 from 62 miles away.

The attic antenna is pointed NNW and recieves Fox 55 out of Wittenberg/Wausau 63 miles away.

The TV antennas are all connected via Channel Master Jointennas and fed into mast or attic mounted CM 7777 amplifiers. The cables are all RG6 quad shield. All lines and the tower are correctly grounded then run into a 4 way splitter that feeds each of the 4 TVs. Reliability is 100% at all times for all channels other than Rhinelander.

It can be done with a bit of luck and a decent signal area. Just for reference, If I turn the Funke or the 91XG WNW, I can get Eau Claire stations 115 miles away about 65-70% of the time, including a reliable lock most nights. If I turn the Funke WSW, I can capture channel 8 LaCrosse from 120 miles away perhaps 25% of the time (nights and mornings mostly). If I turn SW, I can get most Madison stations at about 100 miles away 75% of the time.

I do not even attempt these areas anymore. I do not want the hassle of a rotor. I want to simply turn to a channel and have it work all the time. Therefore, my antennas are fixed as stated above.

TVfool.com can tell you if you you have a shot at Milwaukee stations. If you live on the north side of the city, I will bet that you have a decent shot. It would cost you the cash for a 91XG, a 7777 amp, some good cable and an A/B antenna switch to find out.

There are enough channels in Milwaukee that I would not consider seperate antennas and Jointennas in Chicago. In my location, with 7 stations in Green Bay, 3 in Wausau and 1 in Rhinelander, it makes sense.

Bill
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post #11 of 22 Old 12-06-2009, 08:50 AM
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There is a large sub-group of radio/video enthusiasts who do what is called 'dxing'. Just google 'hdtv dxing' and you can learn all you want to know and more.

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post #12 of 22 Old 12-06-2009, 10:52 AM
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Quote:
Originally Posted by JasG View Post

There is a large sub-group of radio/video enthusiasts who do what is called 'dxing'. Just google 'hdtv dxing' and you can learn all you want to know and more.

Yes, and lots of them participate here.

Just keep in mind dxing is more of a sport or hobby than conventional TV viewing.

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post #13 of 22 Old 12-06-2009, 03:48 PM
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Milwaukee is about 60 miles from me, and Chicago is about 40 (and Rockford 45).

After my second rotor went out in the last, couple of years, I just got tired of it and gave up on dealing with Milwaukee. I just wanted to enjoy watching TV (I have an indoor antenna on a remote-controlled A/B switch with my outdoor one, which still gets me all of the the Rockford channels, but I hardly ever even watch them, anyway - nothing really any different there, and their CW and MyTV are both SD subchannels, unlike here).

There are a few things I watched occasionally on the Milwaukee channels - like on their 1080i, subchannel-less PBS-HD station (makes me want to cry when I remember that ours looked like that at one time, too), or their more recent addition of a decent music video sub - but it really wasn't worth the hassles anymore. The initial thrill of DX'ing wore off, once I actually had access to the channels for a couple of years. The majority of the programming is just redundant, and I have DVR's now, so I don't "need" multiple channels showing the same stuff.

They do show Packers games, and the occasional Brewers game on a Saturday (although barely watchable on an extremely bad, blurry, SD subchannel) - but unless you're particularly a fan of those teams, you can live without them, because there are plenty of other Pro sports to watch just on the local channels here in Chicago (and if you're a Cub fan - which, thank God in heaven I'm not - I'm not a masochist - you might see one or two games per year when the Brewers play them that you wouldn't see OTA here - big deal - two teams going nowhere fast).
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post #14 of 22 Old 12-06-2009, 04:09 PM
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Rammitinski hit it on the head for me also. While I can get other markets, I stick with my local Green Bay market and the nearby Wausau market. The reason for two markets for me...during non-prime time hours, programming is different. Plus, Wausau stations show "out of market" games for the NFL. For instance, Green bay stations can not show the second game of an NFL double header when the Packers play at home. Wausau can. Also, Wausau has been known to show Vikings games as their market stretches west towards the twin cities. I can many times catch another NFC North game that is not shown in Green Bay.

Other than that, the prior post is right on...a lot of redundancy. Wausau has SD subs of WB and MyNetwork TV, while Green Bay has HD channels. Yet, Wausau has This TV and Untamed Sports TV and Rhinelander has NBC Universal Sports. These are 3 sub-channels that are not available in the Green Bay market.

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post #15 of 22 Old 12-06-2009, 04:21 PM
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Quote:
Originally Posted by Ken H View Post

Just keep in mind dxing is more of a sport or hobby than conventional TV viewing.

Yep, knew that - but I'm assuming that they also know a lot about reception of difficult long distance signals.

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post #16 of 22 Old 12-06-2009, 05:25 PM
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Quote:
Originally Posted by Awesomeness View Post

How many feet high was the antenna before you raised it to 55'?

the tower has been at 47' from the initial setup, over a year ago (long before the transition, although I did add a 12' pipe and rotor this past Spring).

Quote:
Originally Posted by Awesomeness View Post

I'm very interested to know what your signal stregnth will go to when you raise the antenna to 65'.

So am I, although I believe I have more of a problem with co-channel stations (ie. four channel 36's from different directions). My reception of WTTG is sporadic, depending upon the weather, and supposedly WITF (which I can't lock) is shown by the FCC as being receivable. I also have WGPT at -113dBm and W36BE-D at 60 miles distance.

As posted by others, there are other mitigating factors, that are more important for good reception.

A good starting point is for the antenna AGL to be 35'+ and at least 3-6' (10' would be ideal) above the roofline, you're field of view should be fairly open and clear of tree growth and good quality materials and workmanship should be used.

As you can see from willscary's setup, it can get elaborate.
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post #17 of 22 Old 12-06-2009, 05:37 PM
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Unlike Rammitinski and willscary, I need my setup to acquire 100% reliable viewing.

CBS - Altoona, PA
NBC - Hagerstown, MD
ABC - Baltimore, MD
FOX - Lancaster, PA
CW - Baltimore, MD (until my local D.C. LD fires up - W51CY)
iON - Martinsburg, WV
MyN - D.C. & Baltimore
RTN - D.C.
FamilyTV - Red Lion, PA
ThisTV - Baltimore, MD (I've lost but will work on it next Spring - I'm thinking I'll need a cut channel antenna that will be housed inside of a Farady Cage (co-channel interference))
PBS - Hagerstown, MD - Martinsburg, WV - Front Royal, VA - (soon) Chambersburg, PA
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post #18 of 22 Old 12-07-2009, 07:50 AM
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I forgot to add, as pointed out previously. Location, location, location is a very important factor. On transition day, I was getting analog stations from TX & LA, along with Pittsburgh, PA.

Trying to stay above the Noise Floor on a good "Tropo" day, can be very difficult for "Deep Fringe" viewing and especially difficult for "Extreme Deep Fringe.".
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post #19 of 22 Old 12-07-2009, 08:09 AM
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Quote:
Originally Posted by systems2000 View Post

ThisTV - Baltimore, MD - I'm thinking I'll need a cut channel antenna that will be housed inside of a Farady Cage (co-channel interference))

Or a pair of stagger stacked off the shelf antennas. http://www.anarc.org/wtfda/stagger.pdf

The mechanical offset for channel 46 is 4 7/16". The difference in the lengths of the RG-6 would be 3 11/16".

Or a pair of horizontally stacked antennas could be configured to place WKBS in a null. (See the bottom of page 1 of the stagger stacking pdf.)
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post #20 of 22 Old 12-12-2009, 09:45 PM
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Yes, it is possible to get dtv signals from other market areas, there are several variables involved though, these would be antenna gain/height, receiver sensitivity, atmospheric conditions, terrain, transmitter pwr/height, etc. I have personally received dtv signals from approximately 250mi away using the Single Bay Gray Hoverman UHF antenna and a good mast mount preamp @ 25ft above ground level which does not even clear my roof. My average distance is about 90mi away on a day to day basis.
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post #21 of 22 Old 12-12-2009, 09:53 PM
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Quote:
Originally Posted by sparkman386 View Post

Yes, it is possible to get dtv signals from other market areas, there are several variables involved though, these would be antenna gain/height, receiver sensitivity, atmospheric conditions, terrain, transmitter pwr/height, etc. I have personally received dtv signals from approximately 250mi away using the Single Bay Gray Hoverman UHF antenna and a good mast mount preamp @ 25ft above ground level which does not even clear my roof. My average distance is about 90mi away on a day to day basis.

Are we talking about receiving or viewing?

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post #22 of 22 Old 12-12-2009, 10:23 PM
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Quote:
Originally Posted by Awesomeness View Post

Is it possible to get HD stations from cities 100 or 200 miles away? Is it possible to get this signal to lock consistantly. For example, for the people living in the Chicago area, is it possible to lock a HD signal from Milwuakee (90 miles away) or Indy (180 miles away)? In addition to the Bears, Cubs, Sox, and Bulls, this would give Chicago the Bucks, Packers, Colts, Brewers, and Pacers games.

I am willing to buy 2 additional antennas and point them in the correct directions. My questions are, how high would these antennas need to be? Is there any correlation betwen height of the antenna and the distance of the signal recieved?

What is the farthest a HD signal can travel and lock consistantly assuming the antenna is big enough and high enough?

Generally, yes, the higher the antenna (on either end) the better the range..
BUT there are a lot of variables....how tall is the transmit antenna? How much ERP (Effective Radiated Power) are they running? There are a couple of math issues that come into play:
Transmit signal in dbm (transmitter power minus cable loss times antenna gain)
Transmit path length (visual or radio horizon)
Path Loss (varies per freq..the higher you go, the more you loose)
Receive antenna gain
Receive antenna height
Curvature of the earth (the K constant)
and more

If the station is using a 2000ft tower, the "visual" horizon is ~Square root of 2 times the height....so 2000x2=4000 Take Sq Rt and you get ~60+ miles. RF or radio horizon is about 1.2-1.4 that (depending on terrain between the tower and viewing antenna/TV...
Add the rcvr antenna range in (say for 30ft high) and you get 70-80miles top reliably. AND this also depends on the power the station is transmitting at and how low a signal you receiver can decode...(which in the DTV realm) you can also cause it not to decode IF it gets overloaded..which is something you may not be able to tell unless you have a special piece of gear called a spectum analyzer...
Hi power CB ops or commerical two way radio ops near your location can cause the DTV tuner to overload...and goodbye signal! People living in Chicago watching out of town signals?? Doubtful...the local signals will likely cause overload or desense of the amp / receiver...Especially with the TV stations being downtown with the antennas..Houston on the other hand, has 2000ft towers SW of town...people on the east, north and northwest side has better chance of distance over those on the south or SW side where the towers/antennas are.
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