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Antenna TV service

By Jskid
Aug 5, 2011
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  1. What is the name of the TV service that comes from an antenna (not satellite)?
    Does one ever have to pay for the service?
    If one wants better service do they simply buy a better antenna?
    What is UHF reception?

    Also what is the difference between digital and analog signal? I kind of don't see how there could be both at the same time...at least how would the TV know to interpret as analog or digital?
     
  2. jobeard

    jobeard TS Ambassador Posts: 9,336   +622

    Over the Air (ie pure Radio Frequency (rf))
    not possible as there's no encryption
    maybe; the directional feature of UHF/VHF make the orientation important, and getting a 'better antenna' is unsightly and expensive
    VHF & UHF are specific groups (aka bands) of frequencies

    it's much like AM vs FM techniques.
    AM changes the amplitude of the RF to create the information.
    FM changes the base frequency to induce the information.

    Analog can co-exist with Digital as the latter is much like cell phone CDMA where
    the information is converted to codes (zeros & ones, sort of like Morse Code) and then put back to create audio/visual portions.
     
  3. mike1959

    mike1959 TS Evangelist Posts: 1,026   +51

    In UK we are changing over to digital over the air TV reception, after using analogue since I can remember. There is a great trade in 'digital' aerials going on, and it seems many people are buying them. That's ok, but there is no difference between analogue aerial and a digital one, all the work on the signal is done inside the set-top box.
    The only reason to buy a new aerial is if the previous one was a narrow bandwidth one, and digital does need a wide bandwidth aerial here. (450MHZ - 850MHZ)
    If you live within about 5 miles of a transmitter you can use an 'indoor' aerial, otherwise an outdoor one is needed, that's a 'yagi' or more popular in USA, a 'billboard' type. The outdoor types give a more powerful signal to the tv tuner, so would give more channels, over an indoor type. It is possible to build your own aerial, at very low cost.
    (We had both analogue and digital at the same time from 2005 to analogue switch-off in April 2011, on the same aerial.)
    Fair to add that roughly 75% of homes use satellite dishes to get the Sky programs for their main tv, and a 'yagi' aerial for any extra TV's around the house. For radio we have A.M, F.M. (VHF 88-108MHZ), & DAB (around 200MHZ).
     
  4. jobeard

    jobeard TS Ambassador Posts: 9,336   +622

    These antenna's are very critical in dimensions of the arms and spacing between them,
    and unless you have prior experience in RF Transmission Theory and Practice,
    IMO you would be far ahead to just buy one from a local supply house.

    Yea, sure - - you can hang a coat hanger out the window and "it will work", but the goal was to improve signal strength and to get a few +db gain takes lots of understanding.
     
  5. captaincranky

    captaincranky TechSpot Addict Posts: 11,702   +1,886

    Well, that and an inline amplifier....;)
     
  6. jobeard

    jobeard TS Ambassador Posts: 9,336   +622

    broadband inline amp? have you seen one?
     
  7. captaincranky

    captaincranky TechSpot Addict Posts: 11,702   +1,886

    I've seen plenty of things at least masquerading as such. Or, another answer might be, "if you're broke enough to want to build an antenna, an amp is probably above the budget also".
     
  8. matrix86

    matrix86 TS Guru Posts: 812   +26

    It's the same thing here in the US. We officially made the full switch on June 12 of 2009. So analog signals are no more in the US.

    Complete analog switch-off dates by country:
    US: 2009
    Japan: late July 2011
    Canada: late August 2011
    UK and Ireland: 2012

    -assuming the world DOESN'T end by 2012 :p

    Australia: 2013
    Philippines and Uruguay: 2015
     
  9. mike1959

    mike1959 TS Evangelist Posts: 1,026   +51

    If money is not a problem then $50 will buy a good tv antenna that will work with both analogue and digital signals. The antenna is the same for both, all the conversion is done in the set-top box or TV.
    If a TV antenna is needed for testing out a PC TV tuner or just out of interest, I built and use the indoor antenna at; http://www.tvantennaplans.com/
    The only bought part is the 300 to 75 ohm balun transformer, about £3 ($5).
     

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