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Thread: best antenna

  1. #1911
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    Quote Originally Posted by abcd567 View Post
    By the way, your user name resembles call sign of amatuer radio operators. Are you an amature radio operator?
    73 DE abcd
    Yes I am http://www.qrz.com/db/k5leh

  2. #1912
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    Quote Originally Posted by K5LEH View Post
    Wow! Great! Nice to have you in this forum.

  3. #1913
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    Quote Originally Posted by K5LEH View Post
    Alway nice to see another "Hammer Chewer" !!!
    Welcome aboard.

  4. #1914
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    WORLD's FIRST RADIO TRANSMITTER, FIRST RADIO RECEIVER & FIRST DIPOLE ANTENNA - 1886


    Photo: Karlsruhe Institute of Technology Archives
    Radio Magic: Heinrich Hertz used the coil [left] and the antennas [right] to produce and detect electromagnetic radiation outside the visible range.

    Hertz’s experimental work on the subject began at the Technische Hochschule (now the Karlsruhe Institute of Technology) in Karlsruhe, Germany, in 1886, and proved that electromagnetic waves, which were earlier predicted mathematically by James Clark Maxwell, physically exist.

    To honour his accomplishment, the unit of frequency is named after him: Hertz, Kilo-Hertz, Mega-Hertz, Gega-Hertz
    Last edited by abcd567; 2014-12-05 at 23:59.

  5. #1915
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    Hi Guys,

    I need your help mates I'm feeding with a DVB-Stick (http://www.amazon.de/gp/product/B00F...ilpage_o04_s00) with the delivered antenna. I get some good results (see Attachment). I recently bought a new Antenna (http://www.amazon.de/gp/product/B000...ilpage_o02_s00) . I connected it with a BNC - MCX Adapter and it works good, but not as good as I expected. So I bought an Amp (http://www.amazon.de/gp/product/B001...ilpage_o06_s00), but it seems that this is broken.
    However, what did I wrong ? I am not an expert in Antennas, so please keep it simple for me*lol*dump_antenna1.jpg

  6. #1916
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    Are you supplying power to the amplifier? Caution that you don't fry the front end of your receiver. It needs to be feed with a blocking power insertion.
    If you ARE powering the amplifier, be aware this amplifier is intended for satellites which typicaly have a 70 ohm impedance. Your radio is probably 50 ohm. This mismatch will slightly degrade the expected performance but not that much.

  7. #1917
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    Also it appears your antenna is intended for 2 meters. You need an antenna for 1090Mhz.

  8. #1918
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    Hi,

    no - i didn't powered the Amp Hm ok, a 2 meters antenna is maybe better for ATC coms... Thanks K5LEH, will look for an 1090mhz Antenna soon. I found one, but the description is in German: http://www.ebay.de/itm/Scannerantenn...item259abe69a9 (the impedance is 50ohm, freq. is between 25 – 2000 MHz)
    Last edited by equi; 2014-12-05 at 19:41.

  9. #1919
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    Good afternoon everyone.

    I am new to the forum, and new to ADS-B antenna's, but I am an Extra class ham, with plenty of junk laying around.

    I am in the final stages of constructing an 8 element Co-Co out of LMR-400 50ohm solid center conductor coax. I have seen many different designs posted, so I wanted to see if I can get some consensus on what you guys have found as best practices.

    At the moment, it is constructed with 8 elements, cut to 1/2 elec WL. I have a 1/4WL stub attached to the top, and the bottom element is directly connected to more LMR-400 for the feedline.

    Would it be best to add another 1/4 elec WL stub of coax between the "top" element and the 1/4WL stub?

    What seems to be the best method for adding a sleeve balun, if one is truly needed?

    Also, if anyone is interested, I might be able to do some "legit" quantitave testing on a few different design concepts at work, in here:
    https://lh3.googleusercontent.com/-a...929_123848.jpg
    with this equipment:
    https://lh4.googleusercontent.com/-8...204_153715.jpg

    This chamber is used to do 3D field strength modeling of devices and antennas from 400mhz to 6ghz. for ADS-B uses, we would inject a signal into the antenna across a bandwidth around 1090Mhz, and test the radiation pattern being emitted from the antenna. This would give us antenna gain and radiation patterns to compare multiple design styles against each other.

    Let me know if you guys want to work something out, I would love to help out however I can.

  10. #1920
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    @zryder94:
    Welcome aboard!
    Wow! You got such a professional test equipment, and anechoic antenna test chamber. Lucky fellow!

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