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.

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4answers
46 views

2.45GHz: constructing a horn of *thin* steel, what are good ways to join the edges (at least one joint along corner?)

TL/DR: How does someone make a good horn antenna system without using expensively made parts? Welding thin steel for this is not something even pro welders can do (it's a specialty app.) What are DIY ...
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3answers
520 views

RigExpert AA-35 - Interpreting The Information

I have a new RigExpert AA-35 antenna analyzer. 1st one I have had & 1st time trying to use an analyzer on an antenna. My questions are very basic and general, but I am having difficulty in ...
3
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1answer
67 views

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 ...
4
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2answers
288 views

Ferrite beads on a wire antenna?

Will putting a ferrite bead or beads near (but not at) the end(s) of a wire antenna electrically lengthen or shorten it? (lower or raise its resonant frequency)?
2
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3answers
301 views

Can I build a Yagi antenna for my Baofeng UV-5R?

I would like to build a Yagi antenna for my Baofeng UV-5R, but I'm a total newbie when it comes to amateur radios. The antenna will be for UHF and shouldn't be too long (like 1.5 meters max). So my ...
2
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1answer
49 views

Dielectric Constant of Insulation/RF Permeability

I recently purchased a 500-foot roll of military surplus 14 AWG stranded copper wire at a hamfest for next to nothing . It is Prestolite M13486/1-6 (spec sheet). It has very thick chlorinated ...
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3answers
67 views

Can I build a guanella balun using single strand wire instead of coax?

I am trying to homebrew a cobweb antenna and need some help understanding the guanella balun used as described here: http://www.karinya.net/g3txq/cobweb/ This author used RG316 coax around the ...
2
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3answers
125 views

High Altitude Balloon Antenna Design

I'm designing a weather balloon with a club at college. We want to build the antenna from scratch to learn more about antennas but are at a loss as to which antenna design would actually work for high ...
33
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4answers
45k views

Effect of different metals for antenna elements

Other than rust, corrosion, and other reactions with air that would make the use of a metal unfavorable, how do different metals affect the performance? Let's give Yagi an example: Let's say I use 4 ...
14
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5answers
36k views

Good wire for wire antenna?

What properties should I look for in a good wire for building a wire antenna? Could anyone recommend something specific for me?
7
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2answers
564 views

Simulating two antennas (transmitter and receiver) using 4nec2 tool

I am trying to find near field mutual coupling affects between two antennas - one being transmitter and other being receiver. The receing antenna is fed with very little voltage (I think, if I don't ...
2
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1answer
215 views

How do I simulate a receiving antenna in EZNEC simulation tool?

I have a situation where I need to find receiving antenna impedance when it’s $\lambda/2$ distance from the transmitting antenna. Both are dipole antennas. Is it possible with EZNEC?
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2answers
86 views

Does RF go through thin corrosion better than DC?

I might have a bit of a problem with my groundplane, but I am unsure. I am using a ground screen instead of radials. The problem is the ground screen is made of galvanized metal, but I can see that a ...
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7answers
6k views

What is the attraction of vertical antennas for HF?

I understand that MW broadcast stations use vertical antennas because that polarization works much better for groundwave propagation. But in amateur radio, I would assume the focus for communications ...
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4answers
102 views

Which 10 m antenna will give the most rejection in one direction for received signals which are vertically polarized?

I want to null out a particular direction so that i can't receive some vertically polarized interference on 10 m coming from that direction. Which 10 m antenna will give the most rejection in one ...
2
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2answers
60 views

Will ferrite rings around a metal pole hide it in an RF sense from my vertical 10 m Yagi?

If i mount my vertical 10 m 4 element yagi directly on a metal pole so that the pole is between the elements and so messes up the radiation pattern and input impedance, if i put lots of type 43 ...
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1answer
202 views

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?
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1answer
49 views

Is there a suitable alternative to using a metal pole to mount a vertical yagi apart from wood and fiber glass?

Does anyone know if a non-metallic pole approx. 4 m long is available that i can use to mount a vertical 10 m 4 element yagi ? that is not wood, PVC or fiber glass as these are either too heavy or not ...
2
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1answer
200 views

When I am told that a dipole must have a determined length, does that include the space between both elements?

I am trying to build an antenna for receiving NOAA satellites and I need to build two 137,5MHz dipoles. When I enter the frequency and width of the wires in a calculator, I obtain that $λ/2=1.09\,\...
5
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5answers
521 views

Loop antenna layout and radiation?

I've got, for the near term, limited resources to put up an HF antenna at my home. One of the options I can manage without excessive cost is a loop, which would enclose the house. I need to transmit ...
4
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6answers
734 views

Tune a very short 3-5m random wire for 40m (around 7.030 MHz) for listening or occasional QRP CW sending

I would like to use a small trx first for listening CW on 7030 kHz and then for transmitting, locally, among friends. My conditions are "prohibitive" as for antennas: a block of flats, 4th floor in ...
3
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1answer
60 views

UHF cubical quad VNA analysis interpretation

I've designed a two element UHF cubical quad. It was designed to resonate at 385 Mhz. I used 0.1mm thick and 1cm wide copper tape instead of wire to lower the antenna Q. I used PVC electrical conduit ...
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0answers
65 views

How do I Construct a Simple FM Antenna?

I recently bought a cheap stereo amplifier with built in FM receiver from Amazon at the first link below. Testing it out today I found the FM reception to be sub-par. All of my local stations that I ...
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1answer
4k views

What is the purpose of a balun and a unun in a feed line?

I have never understood how a balun or a unun works and under which situation I need to use either of them in an antenna feed line.
1
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1answer
60 views

Need help understanding the gain on antenna pattern plots

My understanding is that the value of the axis (like -10 / 0 dB) refers to the maximum antenna gain (e.g. 12dbi). So, if a ...
3
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1answer
119 views

How do I design a dual band LPDA antenna?

Im not sure if this is the best place to ask a question like this but its the best place i could find. My goal is to build a dual band antenna similar to this one. That covers ...
3
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2answers
115 views

House wiring as an antenna on HF and 2 meters?

The apartment I live in is a 1970s type without access to the outdoors. It does have a balcony. A 2m transceiver is the only radio which will enable me to reach the ham world. Would be possible to ...
2
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0answers
41 views

What's the issue with stainless steel antenna elements? [duplicate]

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 ...
1
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3answers
126 views

2m 5-element yagi with staggered driven elements

I have seen sketches of 3-element 2m yagi antennas in which the driven dipole elements are staggered i.e., one element is positioned slightly in front of the other along the length of the (plastic) ...
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0answers
30 views

Unsure how to assemble Shakespeare SSB antenna; not working [closed]

Have 23 foot Shakespeare SSB antenna. Can not connect through the side feed termination band? Antenna not working? What is the band supposed to look like? Is the termination band supposed to be ...
1
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1answer
78 views

Radio antenna for my FM receiver / Android FM

I want to make a radio antenna at home which will be able to receive all FM frequencies for my FM radio or Android FM. How do I make it? Frequency it can catch : 88 - 108 MHz Thanks.
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3answers
18k views
1
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1answer
42 views

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 ...
5
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3answers
639 views

Tiger Tail + capacitive coupling… what's the interaction?

I've been working on a 2m setup for hiking. My goal is to have the best possible antenna that can be used while walking, and that won't get damaged if I walk under a low branch or some other forest ...
7
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4answers
414 views

Antenna options for a 10x20m property with a large metal roof?

I live in a house that sits in the middle of the city, in a lot 10x20m in size. The first 6x10m are covered by a metal roof with a rather low angle (IIRC only 50cm difference between the highest and ...
6
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4answers
459 views

Weather-proofing antenna connections

Here's a problem: you buy a fancy new vertical for a fair bit of coin, but there's no coax connector on the thing. There are just screw terminals. You need to attach coax to it, but in such a way ...
3
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2answers
815 views

Does a receiving antenna need radials?

I am very new to radio and am using two 433MHz 1/4 wavelength monopole antennas to send and receive data. On the transmitting antenna I'm going to add radials (as it is the standard in my application)...
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2answers
75 views

Matching a 188 ohm antenna to an unbalanced input that expects a 50 ohm antenna

I am new to RF field and trying to use an Archimedean Spiral Antenna design from this paper to capture 915MHz RF for the P2110B power harvester chip. The estimated antenna impedance is 188 Ohm (see ...
8
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4answers
219 views

Why are there differences in antennas that depend on electrical component and magnetic component of a radio wave?

I understand the idea that when we are targeting the electrical component of the radio waves we need to have some form of a linear conductor that receives the electrical component, this creates a ...
20
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3answers
3k views

Can I build a radio telescope out of a parabolic TV satellite dish?

I have the possibility to buy a very inexpensive 2.4m parabolic satellite dish and I would like to build a radio telescope from it. Originally this dish was designed to be a satellite TV antenna. ...
1
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2answers
70 views

Will close-loop metal hangers affect antenna radiation?

I'm working on a kite-supported antenna for an 80m QRP rig -- to be flown at beaches, on mountaintops, and possibly other places where I want to work HF but don't want to lug poles or give up ...
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2answers
1k views

How to best connect an FM transmitting GPIO pin to an antenna?

I'm trying to use a RaspberryPi3 as a FM transmitter, using pifm and/or PiFmRds to send audio in 88-108 MHz band. The RPi can then use the GPIO-4 pin to transmit between ...
3
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1answer
598 views

3 Band (80-40-20 Meter) Fan Dipole Tuning Question

I built a fan dipole according to the basic instructions in the SRI publication describing the theory and basic design. My questions is about next steps in tuning for the various bands. I am ...
2
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2answers
90 views

Low mass, low frequency transmission line

I'm interested in a low frequency (10 MHz - 100 MHz) radio receiver array, made up of crossed dipole antennas. I'm working on a design project mainly focused on the mechanical engineering side of ...
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5answers
6k views

Aluminum vs copper antenna element lengths

Does the particular metal used in antenna elements make any difference in element length or spacing, i.e. 1/2" aluminum tube vs 1/2" copper tube? I know that length and diameter have an effect on ...
1
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1answer
94 views

How do I use multiple antennas with two or more radios?

I'm building multiple antennas tuned to different amateur bands and would like them connected to my SDR for remote listening and analysis, and a handheld radio for transmission, which I may upgrade or ...
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2answers
113 views

How can a vertical Yagi for 10 m be mounted on on a vertical metal mast and be made to work properly?

From a reply to a previous post I've been told that a horizontal tube half a wavelength long mounted right at the junction between the boom on a vertically mounted yagi and a vertical metal pole will ...
5
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3answers
3k views

What type of solder is best suited for radio and electronic use?

Many types of solder are available today, such as acid-core, silver, rosin-core and aluminum solder. What kind should I use for building antennas and radio equipment? Why? From test question: T7D08
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2answers
70 views

Proper magnetic mount placement on roof

I have a Nissan Versa 2012 (hatchback). It comes with one of those default antennas at the back/center of the roof, for listening to AM/FM radio stations. I have a dual band mag-mount (TRAM 1185), ...
3
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2answers
181 views

How does an E-Z-O Antenna work and why does it appear in Wikipedia's article on quad antennas?

How are the conductors/radiators in the E-Z-O Antenna configured, and why is it described in Wikipedia's article Quad antenna? I see three circles and a spider web of wires inside each, but from an ...