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  1. #1
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    Co-Phasing CoCo's with DVB-T's

    Remember back in the day, when we had Citizen Band Radio's and to get that extra distance, we used to Co-Phase 2 identical Antenna's approx 10 feet apart?

    Can the same apply with CoCo's into a single NooElec DVB-T2 dongle or would it fry the dongle due to too much data coming into it?

    I have a good 270 degree coverage with my single CoCo at the rear of my house but I also have a high conifer tree in front yard, which is blocking the remainder 90 degrees and it is impossible for me to push my current antenna any higher and so, I thought about putting an identical CoCo in the front yard and probably Co-Phase the two together into one dongle, so that I have full 360 degrees coverage.

    Is it possible?
    T-EGBB16

    Hardware: NooElec DVB-T2 Dongle, Raspi Pi2 Mod B, 6dB Collinear Antenna, Nevis Pre-Amp & 1090mhz SAW Filter, 9mtrs WF100 Cable and 28ft Mast.
    Software: Rasbain Jessie Lite, FR24 Feeder, Dump1090mutab and VRS.
    Stats for Mar 18, 2016. Uptime:100%. Aircraft seen:2,012. Positions Reported:486,817. Maximum Distance:243nm (Stats provided by FR24)

  2. #2
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    By far nothing compares to CB when it comes to wonders driven by myths. You won't get any improvement by whatever phased antenna array unless you place one of it beyond the conifer. If you can't go beyond cut the tree.

  3. #3
    Passenger K5TED's Avatar
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    Quote Originally Posted by Responder View Post
    Remember back in the day, when we had Citizen Band Radio's and to get that extra distance, we used to Co-Phase 2 identical Antenna's approx 10 feet apart?

    Can the same apply with CoCo's into a single NooElec DVB-T2 dongle or would it fry the dongle due to too much data coming into it?

    I have a good 270 degree coverage with my single CoCo at the rear of my house but I also have a high conifer tree in front yard, which is blocking the remainder 90 degrees and it is impossible for me to push my current antenna any higher and so, I thought about putting an identical CoCo in the front yard and probably Co-Phase the two together into one dongle, so that I have full 360 degrees coverage.

    Is it possible?
    Phased antenna arrays are certainly not uncommon, or solely in the realm of CB. Antenna stacking is typical in all sorts of radio communications applications, and relies on phasing harnesses to bring it all together.

    The problem here lies not with the concept of phasing your vertical antennas, but the fact that phasing relies on precise lengths and spacing based on a fraction of wavelength. Because 1090MHz is such a high frequency, your phasing harness would be only inches in length, not feet. At that frequency, even a tiny imperfection could result in an out of phase system, effectively cancelling out signals. The physics involved wouldn't allow you to spread the antennas far apart.

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    Quote Originally Posted by K5TED View Post
    Phased antenna arrays are certainly not uncommon, or solely in the realm of CB. Antenna stacking is typical in all sorts of radio communications applications, and relies on phasing harnesses to bring it all together.

    The problem here lies not with the concept of phasing your vertical antennas, but the fact that phasing relies on precise lengths and spacing based on a fraction of wavelength. Because 1090MHz is such a high frequency, your phasing harness would be only inches in length, not feet. At that frequency, even a tiny imperfection could result in an out of phase system, effectively cancelling out signals. The physics involved wouldn't allow you to spread the antennas far apart.
    Many thanks K5TED for your reply. I understand what you're saying. I would need approx 40 feet between my antenna's and so, this wouldn't work.

    So, I'm gonna have to do what rueckwaertsflieger suggests and cut the tree down - well, just the top 5 feet anyway. Chainsaw Time haha
    T-EGBB16

    Hardware: NooElec DVB-T2 Dongle, Raspi Pi2 Mod B, 6dB Collinear Antenna, Nevis Pre-Amp & 1090mhz SAW Filter, 9mtrs WF100 Cable and 28ft Mast.
    Software: Rasbain Jessie Lite, FR24 Feeder, Dump1090mutab and VRS.
    Stats for Mar 18, 2016. Uptime:100%. Aircraft seen:2,012. Positions Reported:486,817. Maximum Distance:243nm (Stats provided by FR24)

  5. #5
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    Quote Originally Posted by Responder View Post
    Many thanks K5TED for your reply. I understand what you're saying. I would need approx 40 feet between my antenna's and so, this wouldn't work.

    So, I'm gonna have to do what rueckwaertsflieger suggests and cut the tree down - well, just the top 5 feet anyway. Chainsaw Time haha
    It does no harm to pollard out the top of a nice conifer every two to three years, it strengthens them and you end up with a healthier tree, so just remember, before you chop, it should never be more than a 1/3rd or the tree can go into shock can die if too much is taken in one go.
    If life is a stage, most of us are unrehearsed...!

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    Quote Originally Posted by DemonLee View Post
    It does no harm to pollard out the top of a nice conifer every two to three years, it strengthens them and you end up with a healthier tree, so just remember, before you chop, it should never be more than a 1/3rd or the tree can go into shock can die if too much is taken in one go.
    The tree is about 30ft high. So, the most I could take off is 10ft (1/3rd). I don't have ladders that can go that high. Might have to get a tree surgeon to do it. I don't want the whole tree removed, as it is a good wind-breaker in high winds. I'll post a pic of this tree tomorrow when it is light outside :-)
    T-EGBB16

    Hardware: NooElec DVB-T2 Dongle, Raspi Pi2 Mod B, 6dB Collinear Antenna, Nevis Pre-Amp & 1090mhz SAW Filter, 9mtrs WF100 Cable and 28ft Mast.
    Software: Rasbain Jessie Lite, FR24 Feeder, Dump1090mutab and VRS.
    Stats for Mar 18, 2016. Uptime:100%. Aircraft seen:2,012. Positions Reported:486,817. Maximum Distance:243nm (Stats provided by FR24)

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