Questions tagged [loop-antenna]
The loop-antenna tag has no usage guidance.
39 questions
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Why does 4:1 loop stick work better
I made a loopstick for my AM radio and I used enameled copper wire of 1 mm (approx) thick to make the loops on a ferrite rod of 1 cm thick and 14 cm long. I made the main loop with the number of turns ...
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Signal improvement using a ferrite rod with a small loop antenna
I have used my small loop antenna (which has a main loop and a coupling loop that can be tuned using a variable capacitor) with an AM radio receiver to receive MW broadcasts. However, the small loop ...
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Optimal antenna configuration for edge-on power transfer
I need to build a MHz antenna that can power an RFID chip that responds to mag field perpendicular to the plane of a loop antenna, e.g, using STL transmitter with a small receiver loop in same plane ...
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What size is the loop antenna for 12.288 MHz?
I would like to know, what the size is for loop antenna driven with 12.288 MHz. I researched many pages on internet, but I want to know just the calculation which is being performed. Below a picture ...
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Does an FM Loop Antenna's Loop diameter affect reception?
I live 75 miles from one of my favorite station's broadcast tower (91.1 FM), and I would like to get better reception.
Currently, I am using a NAD 4150 Tuner with a T style antenna. I ran it out a ...
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generic antenna tuner term: impedance matching vs real tuner
Generally, an antenna tuner is nothing more than an impedance matcher. Badly termed, as it does not tunes any antenna.
For loop antennas though this is not the case. The antenna tuner does not do any ...
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Automatic switching of RX antenna -- xcvr has only one antenna connection (SO-259)
I have a local noise problem that's pretty intractable, especially on low bands. I'd like to at least experiment with a loop-on-ground RX antenna -- I've got a 1/4 acre to play with. My IC-718 has ...
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How does a Large Loop Antenna work physically?
I am learning about loop antennas at the moment. I read that the response of a small loop Antenna is proportional to the rate of change of magnetic flux through the loop which causes a uniform current ...
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What is the differece between a large loop antenna and a small loop antenna in terms of their response to an electromagnetic wave?
There is something that I don't get. I read that a small loop antenna (also called magnetic loop) responds more to the magnetic field than a large loop antenna does. I was wondering why this is the ...
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How do I rewire a simple a.m. loop antenna that became unwound?
This antenna has been around for decades and the design is as basic as can be.
Somehow the antenna I'd been using, became unwound. The total length of the wire is 4.9ft.
I need to know the proper ...
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Is it necessary to have a "loop" antenna to make the primary antenna work?
I know nothing of ham radios. However, my elderly uncle, who lives next door to me has a ham radio. He has a very tall antenna. He gets a friend of his to string what looks like to me, an "air ...
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Why are loopstick ferrite antennas commonly wound with Litz wire?
What is the advantage of using Litz wire to wind ferrite (loopstick) antennas? How much of an advantage in what characteristic does this type of wire provide? (over generic single strand enameled or ...
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Debugging SM0VPO's spiral loop antenna build
I had built SM0VPO's spiral loop antenna. And here it is.
Recently I got myself a NanoVNA to see how finnicky it is to be tuned with that poor man's tuning cap. I brought it from 12 MHz into the 14 ...
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Loop Antenna Construction
I have a loop antenna.
When I connect the probe from my oscilloscope, does the probe also act as an antenna? If so, how should I fix that? I read about feeding technique, but I still do not ...
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Multi-turn large/full-wave loop antennas?
There seem to be lots of descriptions and/or articles on using multiple turns of conducting element in small magnetic loop antennas (STLs). But I haven't found any information on full size full wave ...
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Can a Loop Antenna send and receive 10,000 miles away
Can we expect a Loop Antenna such as a Chameleon F-Loop Antenna transmit and receive from the USA's midwest to Australia on HF using an average 100 watt SSB transmitter and an average receiver?
If so,...
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Amplified RX-only loop antennas for DX operation?
I was reading up on the different amplified loop antennas, like the W6LVP or the MLA-30.
Most reviews say "great reception", or show a SDR waterfall with a lot of stations, or show a random station ...
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On a horizontally setup 20m delta loop I am looking to determine the calculations for the proper length of a feed wire
Base of loop will be about 6 feet above ground. RG-8 or 213 will be used for the feed wire. Ugly balun as well.
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Is a balun really necessary for a small loop antenna?
I am in the process of designing a small receiving loop antenna for the lower HF bands. By small I mean a circumference of less than $0.2\lambda$. Thus, a uniform current distribution can rightly be ...
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Antenna tuner design
In a related question about a broadband antenna for SDR it was suggested me to build or buy an antenna tuner.
Since maybe it was not clear to everybody, I'm designing an antenna tuner for reception, ...
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Why is self-resonance important in a loop antenna?
I visited a "small loop antenna" calculator web site today and fed in my horizontal loop gepmetry, curious to see what it would say. 2" dia wire, 72' circumference, 3.935MHz. Interesting results, ...
- 52.4k
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Basic antenna matching theory?
I'm fairly new to antenna matching, other than having built a base loaded vertical.
I'm also new to EZNEC and I tried to simulate an horizontal loop. I arbitrarily chose a 10x10M loop, so I added 4 ...
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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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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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cubical quad reflector tuning stub design
I am currently building a two element portative cubical quad with one reflector and one driven element. the conductors of the driven element and reflector are encased in pvc tubing.
I was wondering ...
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Choke at feed point of delta loop with Q match
I am working on putting together a 40 meter delta loop using a 1/4 wavelength of RG-6 as the matching section. However I'm unsure of where to create my feedpoint choke.
Do I coil up the RG6 right at ...
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How do active loop vs. passive loop differ in terms of noise rejection?
As a urban ham (Harvard Square, Cambridge MA), I'm on the hunt for RFI rejecting antenna configurations. After hours of research, I've come across many strong recommendations for loop antennas, since ...
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Physics behind this decametric radio telescope
I am following this design for a simple decametric radio telescope.
I understand the principle that a radio wave hits the metal inducing an electric current that can be measured, but I do not ...
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Why are variable capacitor plates made from aluminium?
This question comes from doing some research into small magnetic loop antennas for HF.
For transmitting, these antennas are often designed with a big, variable, air (or vacuum) tuning capacitor (e.g. ...
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interdigital (finger) capacitor bank for fine tuning of differential loop antenna
I am attempting to implement a PCB trace antenna; namely the sample in this document. Thing is the 1.17 pF for Cp1 is quite hard to achieve in a cost efficient manner with 0603 caps (I loath those ...
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Is it possible to determine if I'm adjusting gamma match in correct direction with an SWR meter and if yes, how?
I've recently obtained a Quad Loop antenna for 2 m and 70 cm that's fed through gamma match, as shown in the picture:
The shorter metal bars are connected to the hot side of the BNC, while the longer ...
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Rules of thumb for large ("somewhat" full wavelength) loop antennas?
I would like to put up a relatively large loop antenna to cover all the HF bands. I have sloping terrain and geographically in a slight "bowl" with hills and/or ridges in many directions.
If I stick ...
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Feed line direction for Quad antenna
I am currently getting my EE degree, and I'm trying to build my first antenna for a weather balloon.
I understand with a dipole, you want the feed line perpendicular to the antenna for at least l/4, ...
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maximum distance omnidirectional antenna
I want to know this omnidirectional antenna's maximum distance:
gain 15 dBi
frequency 2400 GHz
power 50 watts
CommunityBot
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Antenna Design for specific directions
I am designing an antenna for a device and was hoping to gain some insight in the correct design direction for the antenna.
The Idea: A receiver & antenna that fits in a 6" diameter by 3" deep ...
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Measuring antenna characteristics without physical access?
There is a loop antenna that was thrown around an attic interior several decades ago, of long forgotten dimensions. I found the feed line. Is there a way to measure what (U.S. amateur) bands on ...
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How to construct a loop antenna for receiving HF?
I have a unused hula-hoop in my garage, and I ran some stranded speaker wire around it once, and attached one side of the wire to the coax shielding, and the other to the coax core wire. Is this the ...
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Does increasing the number of turns on a loop antenna decrease frequency operation?
Lets say I want to make a VLF loop antenna for a Sub AM radio band. I don't want a full wavelength because that would be a humongous antenna. Would I wind more turns of wire to decrease the frequency ...
CommunityBot
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Does propagation affect magnetic and electric fields equally?
In the HF bands loop antennas are common, which, if I understand correctly, emit most of their radio energy into the magnetic field, whereas most dipoles emit largely into the electric field.
To take ...
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