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Author Topic: Endfed Antenna for 20m (or even 40m)?  (Read 627 times)
N2KIN
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Posts: 42


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« on: May 09, 2007, 02:52:31 PM »

Hello all,

It's been several years since I left the world of HF and I'm planning on getting back to the hobby. I live in a apartment that is about 40 feet above ground. I spoke with the management and they said rooftop access is no-no. So that basiclly leaves me in a situation where I have to install "stealthy" antenna..

I would like to run a dipole with one leg down from the window sill to the ground (40 feet) and the other leg loops around the room act as a counterpoise(prob 20 feet). I would like to get 20m but 40m would be even better.

I understand that the two legs won't be balanced, but is it possible to run both legs down the window? I've read elsewhere that separation is important when running both wires parallel and it's best to run it in a V configuration. The window is about 5 feet wide so that would be the maximum separation between the two legs.

Thank you,
Dennis
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KA1YUW
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Posts: 43




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« Reply #1 on: May 09, 2007, 07:47:34 PM »

Par makes end fed antennas for each band. You may want to check out them or mfj and b&w makes a whip with loading coil to sit on window sill.
good luck
john ka1yuw
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W4FID
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Posts: 129




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« Reply #2 on: May 10, 2007, 03:51:55 PM »

You can run a "hot" quarter wave long end fed wire from the transmitter and a quarter wave long counterpoise from the ground terminal on your rig. Bend if/as needed to fit the hot one along/around the ceiling and the ground one along/around the base board. Make one set for each band -- just keep them a little ways apart to keep them from detuning each other. Plan on using an antenna analizer to trim them to length for low SWR. Or use a tuner.

REMEMNER -- BOTH WIRES WILL HAVE HIGH VOLTAGE -- EVEN A FEW THOUSAND VOLTS AT THE ENDS FOR A 100 WATT RIG -- SO DON'T LET THEM BE TOUCHED BY PEOPLE/PETS AND BE SURE THEY DON'T ARC TO ANYTHING AND START A FIRE. THAT WILL REALLY PISS YOUR INSURANCE GUY OFF!  ALSO REMEMBER RF EXPOSURE SINCE YOU'LL BE CLOSE TO THEM AND IN THE FIELD. LESS POWER AND SHORTER OPERATING TIME IS BETTER FOR THIS TRICK ........... BUT IT IS A SLICK / STEALTH / EASY WAY T GET ON THE AIR.
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NG0K
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Posts: 335




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« Reply #3 on: May 11, 2007, 07:44:44 PM »

I was reading about a 20m C-pole antenna.   It's a 1/2 wave dipole that is folded.  For 20m it's about 18 feet tall and 3 feet wide.  Normally fed on the bottom end with coax, but I'll bet it will work upside down by hanging it out the window.  You could make it stealth.    Search for C-pole and a couple of good websites pop up.

Doug NG0K
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73, Doug - NG0K
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