Amazing explanations in all your videos!! I do have a (potentially dumb) question, but can water act as the ground plane? I'm asking because I've built a water quality monitoring buoy which sends data via LoRaWAN to my own gateway. It worked okay during testing while it was nearby at a dock, but for my next test it is located in the middle of a bay and seems not to connect unless you get very close to it. I'm realizing from your videos that the dipole antenna provided by Arduino is mounted in the wrong orientation, but I will fix that. But I'm wondering if I could somehow use the water itself as the ground plane, since it's floating in water, and water is pretty conductive. Thanks in advance if you have time to consider and respond! Cheers!
Hi, thanks for your videos, they help me to learn a lot more on antennas and RF :) If the RSSI levels in Rx are roughly the same, what may explain the difference in time to receive 15 messages (monopoles taking more time)? I have an hypothesis, that is: when you do the average RSSI calculation, only the received packets (which have sufficiently good RSSI and SNR) are being taken into account, what can give the false impression that the power received is roughly the same for both antennas. In this case, I'm assuming that the received RSSI is close to the sensitivity limit. Does that makes sense? Thanks again for the content you publish!
What connector did you use to connect the main radiator to the so239 connector? I usually solder but I would like to be able to clamp it down like you did. I don't know the name of that device though. Thank you.
Thank-you so much for this and the other videos in the series. The subject is clearly explained and it is good to be able to pause the video to look at the data and think about them before moving on.
Please note, the way you compare the different antanna's is not correct. In order to get correct results you should tune the antenna's to the frequency you choose for the measurement.
Hi Raymond, do you mean for example that my monopole antenna was not correctly tuned at 868 MHz, and therefore I should not compare it with the tuned dipole antenna?
Hi Raymond, you are absolutely right. That is the point I am unsuccessfully trying to make. Looking at your response I failed to get my point across. Let me explain it better: As you see in the video the ¼λ monopole without ground plane has a VSWR > 2 and I am ridiculously comparing it to a well tuned sleeve dipole antenna. The reason why I am showing this comparison is to show you the effect. But a ¼λ monopole without ground plane CANNOT be tuned to a VSWR < 2. I have used the 4NEC2 program and used the optimised functionality and was not able to lower the VSWR smaller than 2 (you can try this yourself). Unfortunately I did not explicitly mentioned this in the video (sorry, my bad). Some LoRa device manufacturers include a wire (approx. ¼λ long) to be used as an antenna. As demonstrated in this video a ¼λ monopole without ground plane has a bad performance. If you use a ¼λ monopole with ground plane with R > ½λ than the monopole antenna has a good performance.
Yes, you can BUT watch out for the maximum allowed ERP in YOUR region. In tutorial 39 is explained, when operating in the EU863-870 ISM band the maximum allowed ERP = 25 mW ≈ 14 dBm To stay within the legal limit you must lower the end node transmission power when you use a Yagi-Uda antenna. I will discuss the Yagi-Uda antenna in tutorial 48.
I think perhaps the ground plane of the LoRa board is better than you think. I bet if found the PCB details you’ll find the board has 2 layers of copper . One layer as a VSS ground plane coupled to vcc and one layer as the reflective ground plane for the monopole. Excellent video! Thanks for all the time you put into making it.
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Hello can you do some video with outdoor antennas from 5Dbi to 12 dbi. For a Helium
Amazing explanations in all your videos!!
I do have a (potentially dumb) question, but can water act as the ground plane? I'm asking because I've built a water quality monitoring buoy which sends data via LoRaWAN to my own gateway. It worked okay during testing while it was nearby at a dock, but for my next test it is located in the middle of a bay and seems not to connect unless you get very close to it. I'm realizing from your videos that the dipole antenna provided by Arduino is mounted in the wrong orientation, but I will fix that. But I'm wondering if I could somehow use the water itself as the ground plane, since it's floating in water, and water is pretty conductive. Thanks in advance if you have time to consider and respond! Cheers!
Thank you so much, this content is perfect. I will make time to watch and study all the tutorials. Greetings from north Africa ( Algeria)
Sir you are excellent your explanation is very nice
Regards
Dr Shukla
Hi, thanks for your videos, they help me to learn a lot more on antennas and RF :)
If the RSSI levels in Rx are roughly the same, what may explain the difference in time to receive 15 messages (monopoles taking more time)?
I have an hypothesis, that is: when you do the average RSSI calculation, only the received packets (which have sufficiently good RSSI and SNR) are being taken into account, what can give the false impression that the power received is roughly the same for both antennas. In this case, I'm assuming that the received RSSI is close to the sensitivity limit.
Does that makes sense?
Thanks again for the content you publish!
Just discovered your Channel and Suscribed. Thank you and complements on the teaching style. ...73
Amazing video tgank you very much!
Hi, thanks for your video, I learnt a lot, I see Raymond point out a mistake in your video, is the lmba/4 ground plane result still correct?
THANK YOU SO MUCH , VERY INFORMATIVE VIDEO
Really good video and very well explained.
What connector did you use to connect the main radiator to the so239 connector? I usually solder but I would like to be able to clamp it down like you did. I don't know the name of that device though. Thank you.
I used the metal part of the terminal strip block, see page 19 www.mobilefish.com/download/lora/lora_part42.pdf
Thank-you so much for this and the other videos in the series. The subject is clearly explained and it is good to be able to pause the video to look at the data and think about them before moving on.
Ben jij ook de persoon die een HNT miner in A'dam heeft, die tot den-haag/rotterdam bereik heeft?
Ik heb geen Helium hotspot.
What a amazing channel!
Please note, the way you compare the different antanna's is not correct. In order to get correct results you should tune the antenna's to the frequency you choose for the measurement.
Hi Raymond, do you mean for example that my monopole antenna was not correctly tuned at 868 MHz, and therefore I should not compare it with the tuned dipole antenna?
@@Mobilefish Yes, exactly. One can only correctly compare antenna's when they both are optimaly tuned to the same frequency .
Hi Raymond, you are absolutely right.
That is the point I am unsuccessfully trying to make.
Looking at your response I failed to get my point across.
Let me explain it better:
As you see in the video the ¼λ monopole without ground plane has a VSWR > 2 and I am ridiculously comparing it to a well tuned sleeve dipole antenna.
The reason why I am showing this comparison is to show you the effect.
But a ¼λ monopole without ground plane CANNOT be tuned to a VSWR < 2.
I have used the 4NEC2 program and used the optimised functionality and was not able to lower the VSWR smaller than 2 (you can try this yourself).
Unfortunately I did not explicitly mentioned this in the video (sorry, my bad).
Some LoRa device manufacturers include a wire (approx. ¼λ long) to be used as an antenna.
As demonstrated in this video a ¼λ monopole without ground plane has a bad performance.
If you use a ¼λ monopole with ground plane with R > ½λ than the monopole antenna has a good performance.
Dense
Hi, can we use yagi antenna instead of using monopole antenna?
Yes, you can BUT watch out for the maximum allowed ERP in YOUR region.
In tutorial 39 is explained, when operating in the EU863-870 ISM band the maximum allowed ERP = 25 mW ≈ 14 dBm
To stay within the legal limit you must lower the end node transmission power when you use a Yagi-Uda antenna.
I will discuss the Yagi-Uda antenna in tutorial 48.
@@Mobilefish okay got it, thank you. Just can't wait for tutorial 48.
I think perhaps the ground plane of the LoRa board is better than you think. I bet if found the PCB details you’ll find the board has 2 layers of copper . One layer as a VSS ground plane coupled to vcc and one layer as the reflective ground plane for the monopole. Excellent video! Thanks for all the time you put into making it.