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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22 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 ...
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3answers
59 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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1answer
60 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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1answer
45 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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1answer
35 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 ...
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2answers
65 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 ...
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2answers
65 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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1answer
131 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 ...
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2answers
86 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
301 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 ...
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4answers
133 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 ...
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3answers
360 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 ...
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1answer
56 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
87 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 ...
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2answers
60 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), ...
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2answers
99 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 ...
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3answers
179 views

What happens to a vertical Yagi when you mount it on a vertical metal pole?

How much difference does a metal pole make when it's sitting in the middle of all the lower elements of my beautiful new highly optimized to the max YO.EXE 10 m yagi ? I get it that the closeness of ...
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2answers
120 views

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,...
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4answers
202 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 ...
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3answers
203 views

antenna in the rain

What kind of changes can be expected in the behavior (resonance, SWR, etc.) of a mobile vertical HF antenna between dry conditions and wet rainy weather? (assume a coax feed-line and low SWR in dry ...
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1answer
66 views

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 ...
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2answers
186 views

Simple Longwire/Dipole Antenna design

In a couple of days I am going to a mountain cabin and I were thinking about making myself a semi broadband antenna for LF/HF (300KHz - 20MHz or so) for receiving only. I was thinking about creating ...
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3answers
143 views

Can I use a helical ground plane radial in the same way that a loading coil works?

I'm working out the science behind mounting an antenna on a vehicle, and I came across the concept of ground planes. This answer says that longer is better but don't worry about it too much, but this ...
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1answer
133 views

Antenna for receiving 868MHz rocket telemetry: QFH(QHA), Helical, or?

I'm building a radio communication system for an amateur rocket project. We've decided to use LoRa 868MHz system. My question is, which antenna for the ground station will be the best choice? We're ...
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1answer
54 views

Effect of small amount of metal on twin-lead

I have a G5RV Jr. antenna on a fiberglass mast at 10m height. The only metal on the mast is a 1/8" thick steel guy ring with stainless steel snap links, plus a few small metal screws. Hanging freely,...
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2answers
602 views

RF Antenna - V pole - Should one leg go to ground and the other to signal?

I'm attempting to follow this white paper in order to build an antenna. This is my first antenna and as such I have a rather simple question. DIY 137 MHz APT Weather satellite antenna by Adam-9A4QV ...
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2answers
160 views

Will wrapping an antenna around my house next to metal affect it?

My unit is 25' by 25' each side and the front is 22' across. The overhang is about one foot with aluminum and vinyl underneath. If I wrap an OCF dipole (fed with 4:1 balun) around this overhang in ...
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1answer
197 views

How to make a ferrite bar antenna for RTL-SDR?

I bought a RTL-SDR (blue one with little MCX antenna). I modified its Q branch, and can receive short wave radio with Degen 31MS antenna now. For MW, Degen 31MS antenna has a ferrite bar antenna ...
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1answer
73 views

Antenna Type of a Chinese Antenna

Recently, I have received an antenna from one of the Chinese manufacturer and they haven't disclosed the detailed specification with us. Below is the picture of my antenna (please ignore the ...
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3answers
430 views

Size of ground plane disk for vertical antennas?

I’m looking for information about the diameter of a ground plane disk that I can use with a regular car radio and car type antennas in my home. DIY would be best, or any other ideas for a antenna that ...
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2answers
126 views

100MHz to 1000MHz Antennas for Transmit and Receive

I am building a ground and wall penetrating frequency modulated continuous wave radar. The only components that I have not been able to track down are the antennas. I need two antennas (one for ...
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2answers
96 views

Running mag loop feedline INSIDE the loop tube

We are building a 4 ft diameter mag loop using 1" copper tube. The coupling loop will be at the top of the loop (we are using a large vacuum cap in a weatherproof box and it is too heavy to be ...
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1answer
87 views

Do Loading Coils Supply “Missing Degrees” to Electrically Short Radiators?

References are made on this and other websites to the effect that loading coils can/will supply "missing degrees" to electrically short radiators. But do they?
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4answers
861 views

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 ...
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1answer
178 views

What does co-phasing of cross-polarized antennas mean?

I was working with the 3GPP release 14.6, and it mentioned that modern communication systems have cross polarized antennas, and in order to perform beam-forming we need to co-phase our pre-coder. Pre-...
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1answer
51 views

Wire dipole antenna proving ground / test bench

i am considering building two movable (concrete base with wheels) non metallic poles with hooks every ten centimeters or so, in order to test wire dipoles of various sizes at various heights with an ...
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1answer
112 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)?
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5answers
471 views

Wire antenna slightly too long

Say I have a wire antenna that is slightly (a few percent) too long for the desired frequency (of resonance or lowest SWR). What are the options, other than cutting the wire(s) and very likely ending ...
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1answer
231 views

Twisting copper wire for a less-flexible DIY antenna

I am making DIY antenna for a home project. The antenna is going to be "V-dipole" with leg length about 53cm. Unfortunately, I didn't find a thick copper wire, but I have a lot of thin core from tv ...
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3answers
170 views

Do PCB antennas suit for NOAA and ADS-B?

I saw many designs for creating DIY antennas for NOAA (~137MHz) and ADS-B (~1090MHz) but never seen it in a PCB implementation. So I have a rookie question: why nobody uses PCB antennas for such ...
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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. ...
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3answers
239 views

Mounting a J-Pole and Yagi on the same mast

I have two 2-meter antennas, a copper J-Pole and a Hy-Gain VB-25FM. The J-Pole is my all-around antenna, what I use for general 2 meter stuff like connecting to my local repeaters using my main 2-...
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2answers
118 views

Antenna design - Ground plane in simulation and in practice

For monopole antennas, the ground plane acts as another arm of an equivalent dipole antenna. I'm wondering how we can expect the behavior of that antenna in practice, because the ground plane is ...
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1answer
170 views

Understanding of NFC Reader Antenna matching

I have been designing a 20 x 20 cm square NFC reader antenna which looks like this: In order to make it work and detect NFC tags at certain distance, it needs to be matched. To do that I was trying ...
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1answer
94 views

NFC coil matching - Q factor improvement

I have been trying to match my NFC reader coil of size 20*20 cm with a three element circuit - one capacitor in series, another in parallel and one resistor in parallel. I have been using Texas ...
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1answer
107 views

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 ...
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1answer
249 views

Is a J-pole an appropriate antenna for mounting to a steel handrail?

Last year, a group of us placed a battery-powered 2m digipeater using a J-pole antenna on a mountaintop. We're planning on doing the same this year except we plan to use a surge arrestor from the feed ...
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1answer
72 views

Will stainless steel bolts work with my copper antenna?

My antenna is copper, elements and the beam. I would like to bolt them together where they cross. Would stainless bolts work? Just sweating them together lets them twist and move some in high winds.
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2answers
108 views

Thermostat wire for antennas?

While checking out the local hardware store wire section, I came across thermostat wire priced significantly lower than other types. I have been trying to determine the reason but details online are ...
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5answers
434 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 ...