Transmitting a vlf signal

panic mode

Joined Oct 10, 2011
5,000
there is no mention of repeaters. and if repeaters were involved, why would range be limited to 300km and not 800km or 20000km? there are several videos showing urban use with some 5km range for point to point connection. and urban setting is practically as hard as it gets due to many obstacles and reflections. one of friends is radio amateur making own units that are carried by wind. they get incredible range thanks to high altitude.
 

crutschow

Joined Mar 14, 2008
38,526
there is no mention of repeaters.
The device connects to the internet, so that is apparently how it transmits signals over a long distance.

From Wikipedia:

The LoRaWAN network architecture consists of three main components:
  • End Devices: These are the small, battery-powered sensors or trackers that are spread out in the field. Each device has a LoRa chip that allows it to transmit small packets of data over long distances using the LoRa radio protocol.
  • Gateways (Base Stations): A gateway is a receiving station that is connected to the internet. It listens for LoRa signals from all the end devices within its range. When a gateway receives a data packet from a device, it forwards it to the central network server without processing it.[21] A key feature of LoRaWAN is that a single data packet from a device can be picked up by multiple gateways simultaneously, which increases the network's reliability.
  • Network Server: This is the central cloud-based software that manages the entire network. It receives the data from all the gateways, removes duplicate messages, and then routes the data to the correct application server. It is also responsible for managing the communication frequencies, data rate, and power for all end devices.[22][23]
 

WBahn

Joined Mar 31, 2012
32,876
The device connects to the internet, so that is apparently how it transmits signals over a long distance.

From Wikipedia:

The LoRaWAN network architecture consists of three main components:
  • End Devices: These are the small, battery-powered sensors or trackers that are spread out in the field. Each device has a LoRa chip that allows it to transmit small packets of data over long distances using the LoRa radio protocol.
  • Gateways (Base Stations): A gateway is a receiving station that is connected to the internet. It listens for LoRa signals from all the end devices within its range. When a gateway receives a data packet from a device, it forwards it to the central network server without processing it.[21] A key feature of LoRaWAN is that a single data packet from a device can be picked up by multiple gateways simultaneously, which increases the network's reliability.
  • Network Server: This is the central cloud-based software that manages the entire network. It receives the data from all the gateways, removes duplicate messages, and then routes the data to the correct application server. It is also responsible for managing the communication frequencies, data rate, and power for all end devices.[22][23]
The End Devices have ranges of typically a few km, up to a 30 km or so under ideal conditions on the ground and maybe 100 km under extreme ideal conditions (airborne or mountain peak to mountain peak).

They do this, however, by exchanging data rate for range.

LoRaWAN Range Specification & its calculation | RF Wireless World

. What Are The Factors Affecting LoRaWAN Range In IoT - Lansitec
 

Thread Starter

Dimbil000

Joined Jan 10, 2026
8
Thank you very much!
Dear crutschow,

Can you please give me your e-mail address (or you can write to my e-mail address: <email address removed>) to explain to you what exactly I want to do and see if you can really help me?

[MODERATION: Please do not include email addresses in public posts. If you wan to speak privately with another member please use the conversation facility which becomes available after you have been here long enough to be trusted by the system.]
 
Last edited by a moderator:

Ya’akov

Joined Jan 27, 2019
10,240
Welcome to AAC.

Your question is underspecified and your reluctance to provide details feels abusive to your potential helpers. Experience suggests that you have decided on a solution from ignorance and presented it as the problem. The question, "what problem are you trying to solve?" is not idle curiosity, it is essential in order to actually help and not just toss out random suggestions.

Since there is a good chance what you will end up doing will run afoul of regulatory limitations and cause interference with licensed radio services, unless you are willing to answer the question about the reason you want to do this, this thread will be closed to further posts. Your cooperation is greatly appreciated. [MODERATION]
 

crutschow

Joined Mar 14, 2008
38,526
Can you please give me your e-mail address (or you can write to my e-mail address: <email address removed>) to explain to you what exactly I want to do and see if you can really help me?
Sorry, I don't do private communications for these problems.
If it can't be discussed publicly on this site, then I'm not interested.
 
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drjohsmith

Joined Dec 13, 2021
1,609
5 Khz , is audio frequency,
i.e any audio amp.
your aerial, needs consideration.
a long wire, to get say quarter wave length, is very long.
a shorter wire will still transmit, but be less efficient
you could use tuning parts on the aerial or even balums

lots there for you to read up on .

for referance , the vlf signals such as the 60 Khz time signals use Mega watts of power, Km long aerials , and rooms full of antenna tunning,

in conclusion,
I cant see your 5 Khz working ,
 

MisterBill2

Joined Jan 23, 2018
27,566
In post #25, "Y" has stated what I was thinking very clearly and adequately. Transmitting an audio frequency a kilometer?? Not a big challenge. Receiving it for any useful communications?? THAT is the somewhat difficult part.
Providing a complete solution without knowing the requirements??? NOT LIKELY TO HAPPEN. aM i AWAR4E OF IT BEING DONE?? yes.
 

MisterBill2

Joined Jan 23, 2018
27,566
Now, a month later, a simple scheme is clear. After you build the 5000 watt amplifier, simply wind an antenna loop of a manageable size that you can tune to resonance at your selected frequency. This will be much more efficient than a straight wire antenna, and allow most of the power to be sent in the selected direction. On the receiving end, another tuned loop antenna should be able to capture a useful amount f signal.
 
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