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Thread: See if you can spot the problem with the following

  1. #11
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    Quote Originally Posted by KJ6BSO View Post
    I made a PSK-31 contact with a friend while he was testing his rig into a dummy load so, yeah, I agree—you can get some RF to radiate off of pretty much anything. That doesn't make it a good antenna, however.

    Cor, I think you're right. That “Special Purpose Part” looks suspiciously like a high-wattage resistor, doesn't it? Check out this page!
    Sort of like the "terminated tilted folded dipole" - which of course, works great for the military because with ALE nobody ain't got no time for antenna tuners or all that, and the huge losses are just overcome with mo powa.
    Jim
    The machine does not isolate us from the great problems of nature but plunges us more deeply into them. - Antoine de Saint-Exupéry



  2. #12
    Might make a fairly good sub-terranian antenna.

    Matt
    grrrrr, arrrrgh

  3. #13
    Master Navigator K4PIH's Avatar
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    Cantenna!
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  4. #14
    Orca Whisperer n2ize's Avatar
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    I get excellent results 160-10m with a lightbulb for an antenna. However I have yet to make a contact with the bulb.
    I keep my 2 feet on the ground, and my head in the twilight zone.

  5. #15
    Conch Master KJ3N's Avatar
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    Quote Originally Posted by n2ize View Post
    I get excellent results 160-10m with a lightbulb for an antenna. However I have yet to make a contact with the bulb.
    Slacker...

    http://www.ok1rr.com/index.php/anten...erything-works
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  6. #16
    'Grumpy old bastid' kb2vxa's Avatar
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    "Might make a fairly good sub-terranian antenna."
    Yeah, raise the antenna for sky wave, bury the antenna for ground wave. Uh huh, that's how ya do it, uh huh.

    I recognized that golden metal box immediately, a wire wound power resistor made to be mounted on a heat sink. I used to work with them and measured a fair amount of inductance when I got curious. Maybe on the antenna it's a loading coil? Just could be, ayup.
    "The universe is under no obligation to make sense to you."
    Neil deGrasse Tyson

    73 de Warren KB2VXA
    Station powered by atomic energy, operator powered by natural gas.

  7. #17
    Orca Whisperer PA5COR's Avatar
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    The resistor will dissipate ( depending on the band used) some or more R.F. and lower the SWR that way.
    The grounded section makes sure the SWR will stay low but efficiency? 25 to maybe 75% through the 20 meter or 66 feet section that radiates.
    As I said before, for some without a good reference antenna he /she will state it is a magic antenna, till he / she puts up a decent dipole at reasonable height.

    Don't forget conditions can vary 60 - 100 dB much mor as the difference between this piece of crap and a decent dipole.
    10 dB gain between 100 watt out or 10 watt efficiency output from the antenna without reference is unnoticeable for some.
    "If the Republicans will stop telling lies about the Democrats, we will stop
    telling the truth about them." - Adlai Stevenson (1900-1965)
    “I’m not liberal/conservative, I’m anti-idiotarian.”
    At some point in the last 20 years, the left moved to the center, and the right moved into a mental institution

  8. #18
    Orca Whisperer W3WN's Avatar
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    Quote Originally Posted by KJ3N View Post
    From one of the FB ham radio groups:
    Your not dedicated till you drive a ground rod home thru the south texas clay. Today i set up my hf20a wire antenna. This antenna needs 2 ground rods. The good news is that i get 1:1 swr from 160-10m no tuner.
    Anyone? Bueller?
    Well, let's see...

    Ignoring the non-technical issues with the post (such as the OP's inability to properly use contractions)...

    The HF20A is, essentially, a dipole/inverted V with a balun/matching network of some sort at the feed point. Although you can also rig it up as an OCF dipole, or even as a delta loop.

    So what the heck do ground rods have to do with a it, from an RF standpoint?

    (As already noted, too, having a 1:1 SWR without a tuner only means that the antenna is presenting a 50 ohm load to the transmitter. Doesn't mean it's radiating a signal. I can find cheaper dummy loads at Mendelson's tent at Dayton.)
    “Nobody is going to feel sorry for us. 90% of the people don’t care, the other 10% are glad it happened.” — Clint Hurdle, 2019

    BAN THE DH!

    Fudd's First Law of Opposition: If you push something hard enough, it WILL fall down.
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  9. #19
    Orca Whisperer W3WN's Avatar
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    Quote Originally Posted by n2ize View Post
    I get excellent results 160-10m with a lightbulb for an antenna. However I have yet to make a contact with the bulb.
    I knew I should have read this thread three months ago...

    Way, way, way back when I was in school and one of the ops at K3CR for the WPA section traffic nets... one night, Walt N3WS checked into the WPAPTN net with an extremely weak signal. Usually he was booming in (6:15 PM EST on 75 meters), since he was only about 2 miles from the club shack. We could hear him, but the NCS that night couldn't. So I called him on the 2 meter repeater to see if he was having a problem.

    He was.

    He'd tuned up the radio and forgotten to take it off the dummy load before checking into the net.

    And the dummy load he was using that night, or so he said? A 100 W light bulb.
    “Nobody is going to feel sorry for us. 90% of the people don’t care, the other 10% are glad it happened.” — Clint Hurdle, 2019

    BAN THE DH!

    Fudd's First Law of Opposition: If you push something hard enough, it WILL fall down.
    Teslacle's Deviant to Fudd's Law: It goes in, it must go out.

    Just remember: Abraham Lincoln didn't die in vain. He died in Washington, DC

    Cutch 300!!!!!

    “Nero fiddled while Rome burned. Trump golfed.” — Bernie Sanders

    Quando Omni Flunkus Moritati


  10. #20
    Whacker Knot WØTKX's Avatar
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    Balun on the left, Gold Standard SWR device on the right.

    "Where would we be without the agitators of the world to attach the electrodes
    of knowledge to the nipples of ignorance?" ~ Professor "Dick" Soloman



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