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Questions tagged [vlf]

Very Low Frequency is the frequency range 3-30 kHz.

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4 answers
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What core material would offer the highest sensitivity in the design of an ELF/VLF handheld rod antenna?

I want to design an ELF/VLF handheld rod antenna. What rod material would offer the highest sensitivity at these low, low frequencies? Below 50 Hz.
Ron K5TDF's user avatar
1 vote
4 answers
173 views

Connecting two sites in the Arctic and Antarctic with a HUGE equatorial repeater? (Science fiction story advice)

TLDR: With infinite resources but real technology (no satellites, and no other repeaters possible), how would you best connect two ideal sites in the Arctic and Antarctic with an ideal, well-equipped ...
Tris - 2E1OAT's user avatar
2 votes
1 answer
208 views

How the ELF-VLF background noise spectrum looks like?

In the ELF-VLF frequency band,some background noise like Schumann resonances shows in the spectrum analyzer as peaks. I want to have a overview look of the background noise of ELF-VLF frequency band,...
kittygirl's user avatar
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0 votes
3 answers
544 views

Does anyone know of a compact ELF wave transmit antenna I can buy or make?

I need to transmit frequencies as low as 1Hz and I know the wavelength is the speed of light but wondered if there has been any breakthroughs in this field? I need a handheld antenna or at least one ...
markbunting's user avatar
4 votes
2 answers
166 views

Why are VLF EM waves labeled as "sonic" in ARRL charts?

In the ARRL Ham Radio License Manual (4th Edition) an Amateur Allocation chart labels VLF with "Audible Range": ...
Jared's user avatar
  • 201
2 votes
2 answers
220 views

Estimating near-field electric field strength at LF (137 kHz)

I'm experimenting with low frequencies, but due to the inherent nature of LF, I strive for more transmit power and bigger antennas. Now of course I want to comply with regulations, which allow (in my ...
kernash's user avatar
  • 23
1 vote
1 answer
288 views

Need a ferrite suppression material for choking 15 kHz to 60 kHz

Electric fence RFI is ruining reception on our VLF lightning receivers, and we need a material to place around neighbors' fence wires to suppress the noise being radiated. Preferably, a split bead, ...
Mike Waters's user avatar
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1 vote
1 answer
2k views

Designing VLF antenna

I was doing some research about the relation between wavelength and antenna size and shape. I was mostly interested in 15KHz rf range. Based on my research I found the following: A squarish shape ...
Samk80's user avatar
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1 vote
1 answer
224 views

How to explain a frequency pic at 1.5 kHz?

I have a pic in the VLF band at 1.5 kHz. What would be the origin of this peak? The graph was obtained by running display_qt in Linux from a laptop.
 j1088099.mvrht.com.'s user avatar
1 vote
2 answers
409 views

Rudementary Impedance measurements for VLF antenna system

I am looking for ideas to improve my Impedance measurements I perform on my VLF antenna system. Due to circumstances my VLF experiments are usually "on location / in a field" so I do not have the ...
Edwin van Mierlo's user avatar
2 votes
1 answer
196 views

Ferrite Rod Price Differences

We are trying to make a VLF geophysics device for our graduate project and we need two ferrite rod antennas (desired length is 6"). Searching on the internet, we have found two ferrite rod suppliers. ...
ecabuk's user avatar
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5 votes
2 answers
501 views

What are the continuous transmissions at the lower end of the spectrum?

I'm fairly new to amateur radio, and I've been using a web-based SDR tool in addition to my own radios. Using this SDR tool shows a lot of activity lower down on the spectrum, such as this: When I ...
user9993's user avatar
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8 votes
1 answer
862 views

Why are there no amateur allocations in the LF and VLF spectrum?

Amateur radio enthusiasts have slices of spectrum at every magnitude of spectrum MF and above, but in the US none are below MF. Why are there no spectrum allocations below 160M?
Adam Davis's user avatar
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2 votes
2 answers
2k views

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 ...
Skyler 440's user avatar
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3 votes
1 answer
258 views

How can I communicate with VLF ground waves [closed]

I willing to try really hard on working with Very Low Frequency waves to get a signal through the earth a few Km. How can I go about putting a signal at the frequency (probably near 10 kilohertz) ...
Skyler 440's user avatar
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