View Full Version : Antenna mounted on a hill?
mdoverstreet
21-Oct-2011, 2:59 AM
Got a question ya'll for this location: http://www.tvfool.com/?option=com_wrapper&Itemid=29&q=id%3d60b5bcd9ccc9e3 which is about 2600 ft. south of the house on a hill that the terrain map says is about 1800 ft. Is it possible to string coax that far and still get a usable signal? Heard that RG11 is good for that kind of a distance. Would there need to be any in-line amps? Could I use two antennas and "bend" the signal like I've read of other people doing instead of stringing? I really want to help get my uncle more channels but I don't want to go 200 ft up either. Would rather go out. That location my still be on our property but if not, I'll ask the person that owns it if I can install an antenna. Thanks!
GroundUrMast
21-Oct-2011, 7:56 AM
Let's be conservative and use Comscope's RG-11 (http://www.mjsales.net/items.asp?FamilyID=190&this_Cat1ID=270&Cat2ID=89) specifications. At 200 MHz the loss would be 1.68 dB per 100 feet, at 700 MHz, the loss is stated as 3.27 dB per100 feet. The loss at the end of 26 hundred feet will be 43.68 dB at 200 MHz and 85.02 dB at 700 MHz.
Yes, you would need several inline amplifiers with slope equalizers to deal with the approximately 40 dB difference in loss between the upper and lower frequencies. An example of the type amplifier needed might be the Pico Macom PIDA-1000 (http://yhst-18278607509093.stores.yahoo.net/pico-0259.html) which would need to be specified with the correct equalizer and power supply (I'm only illustrating the basic concept, not recommending the PIDA-1000). Presuming the PIDA was compatible with the cable chosen, three or four would be needed to deal with the losses indicated above. The noise figure of the PIDA-1000 is specified as 5 dB... four of theses in series will drastically reduce the available noise margins of all the signals. Only the signals with NM values of 20 dB or above would survive the trip down the line. (Note the list price of the PIDA-1000 is over $600 each.)
The number of amplifiers could no doubt be reduced if you opted to use 1/2" hard-line which would have lower loss than RG-11.
More expensive options would include cable TV head-end components that would receive the OTA-ATSC signal and then shift the frequency down into the low VHF range. The least expensive solution I have come across retails at around $750 per RF channel. Example: Holland HPH-860AD (http://www.techtoolsupply.com/ProductDetails.asp?ProductCode=HPH-860AD) which has fairly stringent requirements for the incoming off air signal level and noise margin. I expect that for most individuals such equipment is cost prohibitive and also well beyond their skill level.
Regarding two antennas bending the signal... There does not appear to be nearly enough signal in the air to make a 'passive repeater' function. A quick glance at a link budget calculator indicates the 1/2 mile path would add more than 90 dB additional path loss. Even with two 20 dBd gain antennas back to back, you'd be left with at least a 50 dB hit. I'm fairly certain the FCC would require you to license the system if you added any type of amplifier to boost the signal through the air.
If your uncle is willing to use a home theater PC, take a look at this idea: http://forum.tvfool.com/showthread.php?t=1286
mdoverstreet
22-Oct-2011, 3:01 AM
LOL! So the short answer is no. Can't be done. Forget about it. Right? Or is there still a slim-to-none chance? I guess I'm more worried about it than he is. I guess I'm taking it as a challenge. He's surrounded by woods and no one else around for miles so how's the FCC going to know if I put an amp in the equation? Lives in BFE. But, I guess he needs to pick the house up and move it up higher. LOL Just kind of aggravates me that he lives in AR but has to watch MO channels. He's good with it. I'm not. LOL Oh well, thought I had it figured out. I was worried there would be a lot of signal loss. At the risk of sounding stupid, and I did some research but apparently not enough, what's hardline? I've read about other people having a lot of success with passive repeaters or stringing coax and just thought I would try it, but it sounds like it wasn't meant to be. Maybe when I hit the Powerball, I can come up with something to help him. Sounds like that's what it is going to take to do it just because of the expenses.
E-mailed several months ago the tech people at all the stations in Little Rock asking about repeaters, but only the tech lady at KTHV answered me. She's a pretty nice person. Rest blew me off apparently. She said they couldn't put one anywhere up there because that would be extending the coverage area. I looked at a coverage map for that channel and where my uncle lives is in the coverage area but yet can't get it, so why couldn't there be a repeater around there?
GroundUrMast
22-Oct-2011, 4:02 AM
Hard-line is used by cable TV providers to build the pole mounted distribution network. !/2" and 3/4" are capable of low attenuation and can carry a lot of current to power inline amplifiers.
You uncles hill is a rather prime location to try the Wifi connected remote tuner idea... I was hoping you were going to send me a plane ticket so I could watch you build the first one...:p
I'm not sure which would cost more, a 200' tower or the remote tuner idea... the tower I think.
mdoverstreet
22-Oct-2011, 4:43 AM
If I win Powerball, I'll build the thing and buy you a ticket. LOL!!
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