long range antenna in urban (not in line of sight)

Discussion in 'General Electronics Chat' started by Zara Engineer, Apr 17, 2015.

  1. Zara Engineer

    Thread Starter Member

    Feb 6, 2015
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    Hello everyone

    what is the best method to transmit a video signal in urban with distance of 1000 feet (approx. 300 m) ?

    is this by using low frequency transmitter and antenna or by simply by using a high power ?

    thank you in advance for your posts .

    I have pleasure to know the answers from your experience :)
     
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    The best method involves working within the regulations of your Country's Telecommunications Agency.
     
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  3. Zara Engineer

    Thread Starter Member

    Feb 6, 2015
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    hello MikeML

    ok and ...
     
  4. Brownout

    Well-Known Member

    Jan 10, 2012
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    Without a line of sight, the only legal way to do this would be to modulate the signal using one of the bands that are open to hobby/experimental transmissions. In the US, there are a few such bands, but there are other restrictions, like maximum power, antenna height, ... I'm not completely up to speed on this topic, but you'll need to be very careful to understand your local regulations. Doing this will probably require that you build or buy a transmitter made for the legal band.
     
  5. Zara Engineer

    Thread Starter Member

    Feb 6, 2015
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    Hello
    ah ok i understood , but the 2.4 Ghz , 1.2 Ghz and 434 Mhz amateur channels cannot be a solution for my problem ?
     
  6. Brownout

    Well-Known Member

    Jan 10, 2012
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    It's very possible they are the only legal solution. BTW, I edited my response, but you already seem to have right idea.
     
  7. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    the 2.4GHz band and higher need a clear line of sight. google up ham radio TV for alternatives to microwave systems
     
  8. bertus

    Administrator

    Apr 5, 2008
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    Hello,

    If you want to stay within a ISM band, you will have to go higher as 900 Mhz:
    http://en.wikipedia.org/wiki/ISM_band

    The lower bands do not allow the bandwidth of a video signal.

    Bertus
     
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  9. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    your other choice is to go higher and use a tower.
     
  10. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Only if you are a licensed amateur, and the signal being transmitted is non-commercial, and meets the third-party content requirements of your country's Communication's Commission.

    For example, as a licensed amateur in the USA, I can transmit video for my own purposes, but I cannot do it for a business, or even if someone is paying me to do it.
     
  11. #12

    Expert

    Nov 30, 2010
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    A higher tower? It's 1000 feet...2 city blocks...1/5th of a mile. Somehow I can't see that as a long distance for an RF transmitter.
    It seems to me the only way to need a higher tower is when transmitting from the basement of your building.
     
  12. Brownout

    Well-Known Member

    Jan 10, 2012
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    I took your advice (although I'm not the questioner) and found this site. Good stuff and sources for some of the equipment that is required

    http://www.hamtv.com/
     
  13. Kermit2

    AAC Fanatic!

    Feb 5, 2010
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    @ #12:
    the OP mentioned he did not have a clear line of sight, and most times a little altitude can fix that. other times you just need some attitude. :)
     
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  14. alfacliff

    Well-Known Member

    Dec 13, 2013
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    uhf works better to penetrate buildings, and antennas with gain are still rather small. you might have to opint the antenna in a different direction to get a reflection around a building.
     
  15. BR-549

    Well-Known Member

    Sep 22, 2013
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    Does it have to be live video? Can it be a series of snapshots, 1/2 minute old?
     
  16. Zara Engineer

    Thread Starter Member

    Feb 6, 2015
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    Hello

    thank you for your replies, i want to try and decide .
     
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