Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Questions tagged [antenna-construction]

Materials and methods for building antennas, and design of supporting (non-conductive) structures. For design of antennas themselves, use [antenna-theory] instead.

288 questions
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Capacitive hats on wire dipoles?

Capacitive hats seem to be advertised as an option for mobile vertical antennas. One mentioned advantage is the they can widen the SWR bandwidth, making the antenna easier to tune. What might be the effect of using capacitive hats, not on a mobile…
hotpaw2
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Is steel or aluminum structurally a better material for catenaries?

I understand that steel is not a good material for antenna wire, but let's consider that I'm using the wire for purely structural support, or I am cladding it with copper to address the RF conductivity issues. Then, which material is more suited to…
Phil Frost - W8II
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Noise bridge use in antenna construction?

How does a noise bridge work? And how can a noise bridge be useful in building, testing, and/or tuning an antenna?
hotpaw2
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Will painting a 4 element 10 m yagi using conductive paint onto the side of a building work?

Will painting a 4 element yagi using conductive paint onto the side of a building work?
Andrew
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Plastic predator bird props --- Are they effective? How to mount them?

Are plastic predator bird props any effective at keeping away real birds from our antennas? Can I mount such a plastic predator bird with screws or does it need to wiggle in the wind to be effective? In the latter case, how do I mount it then? The…
on4aa
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have an unwanted radio tower

I have a 190 foot tall am/fm radio tower I need to take down. Taking it down with big enough crane and manlifts and a torque crew will be quite expensive. It is a guyed lattice tower that if necessary I will let fall over by disconnecting one of…
slipperyhill
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If a sealed, non-airtight pipe is used as antenna element, how big of a problem is condensate trapped inside?

I'm building a vertical antenna. The lowest portion of its element consists of 3/4" type M copper pipe, with end caps that will be soldered on and 3/8-24 screws poking through at both ends (so the bottom can screw into a 3/8-24 mobile mount, and the…
Bitbang3r
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Somewhat-directional (cardioid?) antenna for receiving ADS-B?

I recently set up my own RTL-SDR-based ADS-B receiver. I live in a Manhattan high-rise with an eastern view, so I do not get any signals from behind the building (almost: I get the occasional reflection). A simple (azimuth-) omni antenna is a waste,…
JayEye
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Shortwave antenna wire — do I care about "corona discharge"?

Just researching an outdoor long run shortwave antenna. I found some cheap wire online but it said it is resistant to corona discharge: Will satisfy a wide number of applications related to medical, electronic or electrical equipment which may be…
Straighteight
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asymmetric shortened dipole

It seems a resonant dipole can be shortened by either loading coils near the center feed point or capacitive "hats" at the ends (and still be resonant). Say I run out of linear physical distance for a full-sized wire dipole by X. What would be the…
hotpaw2
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Spacing Between Antenna Ends and Mast

How do I determine the amount of space needed between the end of a wire antenna and the mast? Edit: End-Fed Antenna Steel pipe one each end
jake9wi
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Antenna Mast near EFHW Inverted L

I have an EFHW 40-10 in inverted L configuration on a fiberglass mast. I'd like to put an aluminum push-up mast nearby for a 6 meter antenna. How close can I get to the EFHW with the push-up mast? The ~67 ft. EFHW extends from 3 feet up to 46 feet…
K8KV
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What's the issue with stainless steel antenna elements?

New ham, here...getting motivated to build some antennas to experiment with and so far my research has shown that stainless steel is not a desirable metal for creating antenna elements - which is a shame because I have access to a LOT of long…
user14945
2
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1 answer

Are stainless steel studs acceptable as a feedpoint connector for an aluminum loop antenna?

Similar to Will stainless steel bolts work with my copper antenna? however my concern here is with electrical properties. With copper antennas I never gave it much thought... just solder the wire. I am finishing a loop antenna using aluminum tube…
Chris K8NVH
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Irrigation system for ground plane

Could a aluminum irrigation system over about two acres work as a ground plane? Pros and cons? Shaped like an F but with 4 horizontals rather than 2. Sometimes it has water in it. The two top horizontals are 60 feet long, the bottom two are about…
James Uzzell
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