Amateur Radio Stack Exchange
Amateur Radio Stack Exchange

Questions tagged [loop-antenna]

32 questions
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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 current in the circuit and thus induces a signal.…
Bartha
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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 distribution in the loop. This would be…
kinu
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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 insulated wire). How do different types of Litz…
hotpaw2
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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 correct way to construct a loop antenna for…
cj5
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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 on 80m, and likely up to 20m (I understand loops…
Zeiss Ikon
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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, not transmission. Searching around I concluded…
Luca
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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 cylinder. Known: Frequencies range from 162.400 to…
Josh Cox
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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 MHz 20 m band range by cutting off the extra wire…
Gunther Schadow
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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 wires, 10M each, 5 segments each (20 segments max…
hjf
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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 smaller beasts that not many hands can solder), and,…
kellogs
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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
minthike
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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 they supposedly respond less to electric fields.…
Jeremy Gilbert
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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 understand the meaning behind the structure. Why does…
cal
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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 with the trees on the high part of my property, it…
natevw - AF7TB
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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 assembly is connected to the ground of the BNC.…
AndrejaKo
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