Questions tagged [antenna-system]
The system composed of an antenna and a feed line, and possibly also an RF ground connection, antenna tuner, balun, phasing device, et cetera.
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How will an off-centre fed (OCF) dipole perform 1ft over a lead flashing roof ridge?
We're fortunate enough to be fully renovating a mid terraced house in the UK. As part of the renovation I'm going to have the contractors run coax through the walls up to the roof where I want to ...
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Antenna Knowledge: Possible Yagis
There are three antennas that have been on the roof of the house we live in. All three have a central loop like the central one shown here. Each has a reflector, a driven element, and a director. They ...
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Poor SWR on short coax line
I have build an antenna for 446mhz I have used 15mm copper tube for the dipoles and RG-58 for the coax. On the horizontal centre line I have created a coil 9 turns around a 25mm former. The feed line ...
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What options do I have for a V/U 4 way 90 degree divider/combiner for satcom
I have a AV2011 satcom antenna that has a Merrimac QHF-2-.312GN power divider/combiner that's good for 225mhz to 400mhz and I'd to replace it with a wider bandwidth version buuut this series doesn't ...
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Antenna - vertical & beam antenna transmit at the same time?
Is it possible to use a vertical antenna and a vertical polarized beam antenna at the same time?
I have a friend that lives about 7 miles away & I can talk to him on 220MHz FM just fine on a ...
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Passive repeater for metal hangar at airport
I'm looking for a fix to an airport radio communication issue. I have an all-metal hangar and have no communication with tower from inside it.
One side of the hangar has line-of-sight with the tower ...
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how to stack parabolic antennas?
I've read that the distance between stacked antennas should be 0.5 to 1 wave lengths - does it mean stacking of parabolic antennas as e.g. for 13 cm EME is not possible?
If yes then the only way to ...
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Loading coil efficiency for 160 meters
I am trying to get my N1CC and would like to get on 160 meters for pota. I can get a vertical that is 39 feet tall set up at the park. I know it will be narrow banded and take a large loading coil, ...
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Why is the measured loss low in an antenna with high swr?
I'm trying to understand the basics of antenna and feedline measurements with losses. I have a background in the sciences but not specifically in engineering. Nevertheless, I was doing some testing ...
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How to use a Johnson Matchbox Antenna Tuner with my Elecraft K3S?
I am experimenting with various antenna designs & feedlines and want to use a Johnson Viking Kilowatt KW Matchbox Antenna Tuner (250-30-3) with my K3S transceiver. The Matchbox was designed to ...
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Transmitted Audio (phone) Is barely understandable. How to pinpoint the cause
This evening while talking with KB1QYH, he ponted out that my audio sounded badly. It sounds like it's being put through a guitar's Wah Wah pedal.
I've reconfirmed this by broadcasting on W1BBV's IC-...
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EFHW Antenna Analysis: Should phase at the antenna feedpoint be similar to the phase presented to the TXRX?
I have a 30m EFHW resonant sloper antenna. I've completed tuning it using my RigExpert and have an excellent SWR at the antenna and the TXRX. I know that some common mode currents are present, so I ...
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What is the radiation pattern of a center fed dipole on the ground?
What is the radiation pattern of a center fed dipole on the ground?
Let's say I have a 1/2 wave dipole and simply place it on the ground. No raising it. What happens?
My specific case is 40 m, CW, ...
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Will antenna insulation protect from RF burns?
Will antenna insulation protect from RF burns?
I understand that antennas should normally be built with their insulation on. Will that insulation protect from RF burns? Up to what power level?
If not:...
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Can I run my antenna coax near a gas line?
I just moved to a new place and would like to put an antenna up in the attic. My shack location is in the basement with the furnace and water heater. In my explorations, I've discovered that there is ...
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