LoRa distance amplifier

Development Hardware
1

I’m trying to find an amplifier for LoRa modules.

I have just bought and used modules T-BEAM V1.1 and the rank of connection is about 3-4 Kms in the field.

I have also found new 868MHz antennas, 550mm long, but I need more voltage and intensity maybe in the circuit to increment the rank to at least 20 Kms.

My purpose is to create a node or big mesh network between devices in a range of 20km.

Does anyone know something about an amplifier to use it with Meshtastic devices??

Thanks

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2

I get 20km by using a $7 moxon antenna on one end and folks have gotten >100km with a moxon on both ends. Check those out.

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3

Are moxon antennas omnidirectional?

I have read about them and the distance is amazing (almost 100 Kms) but it seems to be needly directional communication.

Do you know something about omnidirectional antennas for 868Mhz T-Beam devices?

4

If you’re looking for a good omni directional, consider reputable sources like digikey… there are many on ebay or other sellers that are questionable.

Look for collinear antennas or sometimes called fiberglass antennas.

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5

maybe this helps

But it is important to remember that the best amplifier is the antenna.

6

Here is my post from another thread today regarding an amp I am testing:

7

I have been going the expensive route, geeze I am going to have to try these things.

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8

Sorry to dig up an old thread but…
its my understanding that power is regulated by the fcc, what is the legality of using an amp?

Im not sure if I care but in Baltimore maryland there are only a few nodes and im in an urban area, I have a 6 story building downtown that I can setup a relay but this will be a few months down the road, my equipment for my first setup is on the way, which will be mobile
so directional antennas wont work

9

If by using the amp the transmitted power exceeds the power regulated by the fcc then its illegal.

10

Link to the Moxon you are using Mr Hamster?

S

11

The maximum output power for North America is +30 dBm ERP (Effective Radiated Power). The band range is from 902 to 928 MHz. There are 104 frequency slots defined with the standard radio preset LongFast . After factory reset the radio will be set to frequency slot 20 with a center frequency of 906.875 MHz.

so do any of these amps exceed fcc regs in the us?

12

The FCC now uses ERP in an effort to include the antenna and its gain factor in the equation. In the past the laws simply stated Peak Envelope Power (PEP), which is 1W for the 902-928Mhz ISM band. 1W is the base rule for the band, however, commercial orgs like power companies can apply for licenses to use the same ISM band at 4W and there was one report of a license to use 12W. This is used for Smart City / Smart Grid functionality with LoraWAN gateways talking directly to electricity service meters on people’s houses.

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