Impressive
Not pushed enough lol. Come to think about it… I’ve got a 900mhz yagi and a pile of stepper motors and controllers.
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I’m not sure why I thought it was Australian or 1200aud, I think I saw SA and just thought of south australia haha, it’s south african and ~1200usd, it was just a FB post but I’ll let you know once they get back to me
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I’m just desperate to improve the range on my Lo-Ra.
I’m more interested in the larger/longer antenna than the ext radios.
Simpler + cheaper
In the mean time I’ve ordered these
Probably 10dbi on the base and 4.5dbi on the rover
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Fascinating!!!
Please be sure to post your results once you’ve tested.
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Yes that is fascinating to be sure. Please do post detailed test results & comparisons!
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I only joined the forum yesterday, but If I can chip in here as I’m a radio comms engineer. One of the fundamental rule of thumbs with radio communication is…
‘it’s not how loud you shout, but how big your ears are’
Using directional antenna is a good solution to increasing range, not only because it increases the gain of the antenna and effective radiated power, but also works in reverse on the receive end. The other benefit it brings is that because the receive is focused, kind of like cupping your hand round your ear to catch a conversation in a crowded room, it cuts out a lot of noise from the other diections. This increases the signal to noise ratio greatly.
Having the additional transmit gain coupled with the lowered noise floor/improved SNR means that you can back the transmit power back off a little.
Not running your transmitter at full power, reduces distortion in the amplifier stage, reducing data errors. This is particularly true in software defined radios like ones in use here.
These are simplistic explainations and aimed at helping non radio people understand rule of thumb tips that make a difference. Hope this is of use and happy to assist with any questions.
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Excellent points. Literally the essence of the old FPV guys did to fly 10 or 20km out with only milliwatts to work of.
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Following on from previous, here’s a practical application of using a directional antenna.
Say the standard Reach setup is a 20dBm output power transmitter with an omni antenna. Omni antennas conceptually are 3dBi gain. So add the two together and you arrive at an EIRP (Effective Isotropic Radiated Power) of 23.
Then you swap this out for a 6dBi yagi. Allow say 0.5dB loss in the patch cable and connectors. Add to the output power and you arrive at a theoretical EIRP of 25.5dBi.
So even if you use the yagi and dial the output power back to around 15dBm output power, you will find that your link will work further due to the lower noise floor, increased SNR and the amplifier stage in the transmitter not reaching saturation.
Most places in the world have local regulations stipulating maximum EIRP for a given frequency and application, so this needs to be taken into account (or not!). But hope this illustarates that you can make big improvements without increasing EIRP at the antenna.
Also, as LoRa is a bi-directional system, this assumes you have matched antennas at either end. Putting a directional antenna at only one end is no good.
Hope this helps
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Very helpful info indeed.
Would you or @RogerM be kind enough to post links to such an antenna and cable? I am clueless when it comes to radio & configurations - but willing to learn.
Thanks in advance
That would be so cool beside my base set up
Sure. What frequency band do you use it on 868 or 915MHz?
You can get antennas that are broadband that will cover both. However if you can narrow it down to one or the other, you will get a more finely tuned antenna that will be more efficient as well as reducing the risk flooding the receiver input with signals from other sources such as nearby cell sites.
It can also be smaller in size.
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