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Thread: anyone know this antenna

  1. #1
    Witch Doctor
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    anyone know this antenna

    http://www.barrettcommunications.com...nantennas.html
    i have some old antenna books could not find any information on it
    it's the 912 model i'm asking about
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  2. #2
    Pope Carlo l NQ6U's Avatar
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    Just looks like a pretty standard dipole to me. You could build one yourself for $20-30, most of that going into the balun.
    All the world’s a stage, but obviously the play is unrehearsed and everybody is ad-libbing his lines. Maybe that’s why it’s hard to tell if we’re living in a tragedy or a farce.

  3. #3
    Administrator N8YX's Avatar
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    That's a T2FD:

    http://www.hard-core-dx.com/nordicdx.../t2design.html

    Broadband, to be sure....but you're not going to be able to run high power unless you source a high-wattage, non-inductive resistor for the thing.

    The above being said, a T2FD makes a great low-noise receiving antenna - but it'll be down an S-unit or so in received signal strength as compared to a dipole of the same dimensions. A lot of DXers use them.
    "Everyone wants to be an AM Gangsta until it's time to start doing AM Gangsta shit."

  4. #4
    Beach Bum
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    The Barrett 912 in the 3 wire terminated configuration is a double first cousin to the cage dipole.
    These were sometimes referred to as a "clothesline antenna" years ago, also closely related to the "T2FD".
    A bit awkward to build from scratch (not as bad as the cage dipole) but broad banded nun the less.
    Would not be my recommendation for a part of the country where snow & ice are common unless built out of very heavy gauge materials.
    Used to be seen commonly at the large commercial stations in the 30's & 40's .

  5. #5
    Conch Master KJ3N's Avatar
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    The minute I see power limitations in the specs, I say "no thanks". I have no desire to waste my power heating up a resistor pack.
    "People Who Don't Want Their Beliefs Laughed at Shouldn't Have Such Funny Beliefs" -AD5MB

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  6. #6
    Witch Doctor
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    thanks i didn't see anything about a resister in the advertising
    if so that just makes it the piece of crap that icom sells for a broadband antenna
    too bad , i have access to ss cable i thought it would make an interesting project to build
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  7. #7
    Conch Master KJ3N's Avatar
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    Quote Originally Posted by VE7MGF View Post
    thanks i didn't see anything about a resister in the advertising
    You won't. It's implied by the simple fact that the claims are 2-30Mhz @ 50 ohms, fed with coax. That's simply not possible without a "matching network" at the feed-point, based on what the 912 looks like. The only thing (IMO) that could present that impedance over that wide a range of frequencies is a resistor. The second hint is the different models with different power ratings. Larger resistors for better heat dissipation at the higher power levels.

    if so that just makes it the piece of crap that icom sells for a broadband antenna
    Icom, Yaesu, B&W, and several others.

    too bad , i have access to ss cable i thought it would make an interesting project to build
    A simple 135 foot dipole, fed with ladder line directly to a tuner, is a perfectly fine "broadband" antenna and will be more efficient than the 912 overall.
    Last edited by KJ3N; 06-30-2012 at 08:34 AM.
    "People Who Don't Want Their Beliefs Laughed at Shouldn't Have Such Funny Beliefs" -AD5MB

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  8. #8
    Witch Doctor
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    i know the length of 135 ft dipole would put it outside my property line
    i just have to go with a folded dipole with about one foot spreaders
    i am still trying to find 14g ladder line around here
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  9. #9
    Conch Master KJ3N's Avatar
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    Quote Originally Posted by VE7MGF View Post
    i know the length of 135 ft dipole would put it outside my property line
    i just have to go with a folded dipole with about one foot spreaders
    How much room do have?

    i am still trying to find 14g ladder line around here
    Why? I run a KW into 18g ladder line.
    "People Who Don't Want Their Beliefs Laughed at Shouldn't Have Such Funny Beliefs" -AD5MB

    "If someone tells you he believes in and talks to an invisible bunny named Harvey, you put him on medication and a regimen of therapy. If someone tells you he believes in and talks to God, well, that's perfectly acceptable. Why that's the case is impossible for me to fathom." - WP2XX



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  10. #10
    Whacker Knot WØTKX's Avatar
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    You can "get away with" about 90' or so with that balanced line doublet.
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