Broadcast TV signal strength measurement

Discussion in 'Wireless & RF Design' started by John P, Dec 28, 2014.

  1. John P

    Thread Starter AAC Fanatic!

    Oct 14, 2008
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    At my house we're trying to be cable cutters, and get free broadcast TV rather than paying a fee. We're in a suburban area about 15 miles from the transmitter, but we're on the wrong side of a hill so it's not a totally favorable situation. I've tried moving the antenna around, and most of the time it works OK, but then quite capriciously it can fail--usually during something my wife really wants to watch! What would definitely help would be to get some kind of numerical measurement which would let me see whether one location is better than another, and then I could put the antenna in the best place and see if it ever fails. I can imagine that a meter that can do this would be expensive though, because it would need its own tuner to select whichever station you wanted to measure the strength for. Has anyone got asn idea of how to do this?
     
  2. #12

    Expert

    Nov 30, 2010
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    One version is called a field strength meter. In 1970, a machine to measure the signal strength of a TV antenna, on any particular channel, cost $450. I bought a battery operated TV and tapped into the AGC signal, just to find the pointing direction of best advantage. Today, the set-top-box that converts digital signals to suit my analog TV can display a signal strength graph on the screen. It still isn't in microvolts, but it's anything at all, and it's way cheaper than $450.
     
  3. BR-549

    Well-Known Member

    Sep 22, 2013
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    What are the frequencies of the stations you are trying to receive?

    What kind of ant. and where is it?

    What and how much feed line?

    How high is hill above ant?

    Going FROM direction of transmitter...is there another hill or some large structure?
     
  4. MaxHeadRoom

    Expert

    Jul 18, 2013
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    When recieving OTA (over the air) channels if more than one, it is often a compromise because unfortunately the transmitters are not all situated in the same direction, if there is one channel in particular (they can fade due to weather conditions also) try swinging the Antenna from side to side while someone watches the reception fade out on each side of the swing, and then aim it at the centre of these two conditions, a little crude, but may work for you.
    There are also a few non- scrambled satellites out there if you fancy putting a dish up for FTA reception.
    Max.
     
  5. alfacliff

    Well-Known Member

    Dec 13, 2013
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    there are recievers like the Icom Ic3 that receive those frequencies. they even display the video if its old style analog.
    there are also field strength meters available based on tv tuners to measure the signal strength.
     
  6. John P

    Thread Starter AAC Fanatic!

    Oct 14, 2008
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    Thanks for the responses, everyone.

    To answer BR-549, the antenna is just a thing from Home Depot, I believe it's this model. They don't tell you to use a preamp and I haven't put one in, although I have one I could install. The stations I'm interested in are all in the same direction, so I thought a directional antenna would be the best kind.
    http://www.amazon.com/Winegard-FreeVision-FV-30BB-HDTV-Antenna/dp/B003L76BJS

    The cable is RG-6 coax, and I have 50 feet of it, with some spare connectors so I can shorten the run if necessary. Although the antenna is rated for outdoor use, I'm planning to put it in the attic unless things seem really desperate. I have tried the attic location with the cable coming down the stairs, and the TV worked--but then it worked most of the time with the antenna in the same room. That's really the point of my question--probably the attic is a better location than downstairs, but how much better? What can I measure that will tell me how good it is, or how close to failure the signal level is?

    Right now the main concern is how to run the cable from the attic to a downstairs location. It's a 2-story house and I don't think I can get the cable into the wall cavity, so it looks as if it will have to go outside.
     
  7. KeepItSimpleStupid

    Well-Known Member

    Mar 4, 2014
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    Jut a few things:
    1. Use www.TVfool.com The NM or noise margin is the best indicator
    2. Dont have the antenna pointing the wrong way.
    3. Some areas are using VHF and UHF; others just UHF.
    4. DTV is all or nothing.
    5. Use a mast mounted amplifier. e.f. CM7777 http://www.solidsignal.com/pview.as...ase&utm_medium=organic&utm_source=google_base You may have to enable the FM trap.
    6, Amplifying a bad signal gives you a bad signal.
    7. The set top box/tuner should have a signal strength meter, What your looking for in the US is an 8VSB signal strength meter.
    8. Look for vents like for the toilet for tunning cable on the outside of them. The pipes that stick out of the roof.
     
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