The real question is why did BetaFPV choose to use the NN02-201 flat antenna. That is a wideband antenna meant for 700MHz up to 7GHz. Its not a tuned 2.4ghz flat antenna and they definitely do exist. Another thing is that the NN02-201 antennas on Digikey are like $3.50 a piece (less for quantity). But I found other chip antennas on Digikey with similar gain but tuned for 2.4GHz for a hell of a lot cheaper, like 60 cents a piece. Makes zero sense to me that they used a wideband antenna. Makes me want to order a couple of the flat antenna receivers and then replace it with some 2.4GHz tuned flat chip antennas to see how they work. Or just order parts and PCBs to make some receivers on my own. Sounds easier to just order some BetaFPV ones though.
Wow! I've never liked and subscribed so fast! I've been looking for information like this for a while and not been able to find such a conclusive and comparable result. Then I dive into your comments section and find the info to just about every other question I could have had! This is a gold mine for us who are just getting into ELRS! Thank you, Thank you!!
Thanks for a very informative video, and I especially like at 6:54 how you explain the results so well that a non-technical guy like myself can understand perfectly what is going on. Overall though the entire video is well explained and easy to understand without having any RF knowledge… now that’s how you know you’re a good presenter 👍🏼😁
This is a fantastic video. My only concern is the chip is horizontal polarisation with all the others vertically polarised . This would have had an affect on its performance. It’s nulls are are side on compared to the others on top too.
I just showed one result in the video, but I also rotated the entire rig 90° so that the top of the antenna pointed towards the test area and the results are the same (although the other antennas did slightly worse with their nulls pointed towards the test area). I didn't create graphs for the other tests, but the data is also on the website in the description.
That's correct! They have determined that there is a flaw in the first revision and will replace them if you bought one. The new ones are in the ballpark of the ceramic tower antennas, but slightly worse. Myself and three other developers have done testing and we're in discussion with BetaFPV about it. I'd say they're arguably usable now for LOS / Racing.
Nicely done comparison mate, awesome data! How do those matek whip antennas go that they bundle with their elrs stuff? Im wondering if i should use a betafpv dipole or the included whip for longer range.
Thanks! The Matek antennas are sleeved dipoles, or at least the ones I have are. You can tell if they are if they have a hard metal sleeve covered in the heatshrink before the active part of the antenna. They have pretty much the same range as the T-style dipoles within the margin of error, with the sleeved dipoles performing very slightly worse if the sleeve part isn't exposed causing them to detune a bit.
@@CapnBry ok cool, yeah I wasnt sure what was going on inside that heat shrink lol. I didn't want to destroy one to find out. As long as they're ok then I'm ok with them :)
Thanks for testing. Now we know the facts. 👍. Not all, because I really wonder why the COM28 SIYI FM30 diversity performs not top range, you mentioned maybe a faulty LNA? I guess the Matek R24-D with a LNA: SE2431L will perform much better, should be the no.1 ? Is COM28 Axis dipole the same technology using as the HM EP1?
Thanks a lot for the Video and also for using metric system. Im looking for the best transmitter antenna for my Jumper T Pro since it comes with a N2420 airgain 2.4GHz antenna inside and Im not sure if its a good antenna or not
Thanks so much! I have always suspected this was the case but you've done the testing to confirm 😁. Ill keep making my own dipoles (T antennas). Just curious do you know if a sleeve performs the same as a T?
The data doesn't really back it up very strongly, but the sleeved dipoles seem to perform just slightly worse than the T-style dipoles but better than the monopole (just the wire itself). In practice it feeeeeels to me like the T perform better on my models but I would never be able to tell in a blind test.
It is built into ExpressLRS master with the debug_rx_linkstats user define (or something like that). Several RX are connected to FTDI cables all connected to the same TX with telemetry turned off. The per-packet stats are then post processed in whatever graphing tool you want, we use jupyter now with pandas and seaborn.
All the current diversity receivers have amplifiers. You can tell if a receiver has one by it having a third chip next to the antenna. It is also listed in the docs: www.expresslrs.org/2.0/hardware/receiver-selection/
@@Onefgear The SNR is how high the signal is over the noise, so 10dB means the signal is over 8x stronger than the noise. Lora can receive in the range from +infinity down to around -3 (yup it can receive if the packet is actually weaker than the noise). So it is no surprise the SNR is almost always positive, because our signal is stronger that the noise.
@@CapnBry Thanks yes I know that. Simply curious why the noise is so high at those signal levels. Is the noise really that high? e.g. Data shows -30dBm with 10-11 dB SNR and so does dBm in the low -90s. Have you measured noise floor?
@@Onefgear oh because the dynamic range of the lora chip can't measure that far down. The reported SNR only can only get up to +12dB before the noise is too far away to compare.
@@nerdCopter the Nano cimes with the t antenna and amp. The Lite can be purchased with the red flattie antenna. The product naming is a bit confusing, but that's because TBS called their receiver the Nano so everybody has to start there sadly.
I’m impressed by your mid century accent
The real question is why did BetaFPV choose to use the NN02-201 flat antenna. That is a wideband antenna meant for 700MHz up to 7GHz. Its not a tuned 2.4ghz flat antenna and they definitely do exist. Another thing is that the NN02-201 antennas on Digikey are like $3.50 a piece (less for quantity). But I found other chip antennas on Digikey with similar gain but tuned for 2.4GHz for a hell of a lot cheaper, like 60 cents a piece. Makes zero sense to me that they used a wideband antenna. Makes me want to order a couple of the flat antenna receivers and then replace it with some 2.4GHz tuned flat chip antennas to see how they work. Or just order parts and PCBs to make some receivers on my own. Sounds easier to just order some BetaFPV ones though.
Finally a scientific approach to comparing pears and apples. Thanks a lot for this study. That's an instant subscribe from me.
Dude! Thanks for doing this. I always wanted to know how all the new receivers compared to one another like this and prefect analysis you did. Thanks
Thank you Cap'n for this testing! Well presented!
Wow! I've never liked and subscribed so fast! I've been looking for information like this for a while and not been able to find such a conclusive and comparable result. Then I dive into your comments section and find the info to just about every other question I could have had!
This is a gold mine for us who are just getting into ELRS! Thank you, Thank you!!
Thanks for a very informative video, and I especially like at 6:54 how you explain the results so well that a non-technical guy like myself can understand perfectly what is going on. Overall though the entire video is well explained and easy to understand without having any RF knowledge… now that’s how you know you’re a good presenter 👍🏼😁
This is a fantastic video. My only concern is the chip is horizontal polarisation with all the others vertically polarised . This would have had an affect on its performance. It’s nulls are are side on compared to the others on top too.
I just showed one result in the video, but I also rotated the entire rig 90° so that the top of the antenna pointed towards the test area and the results are the same (although the other antennas did slightly worse with their nulls pointed towards the test area). I didn't create graphs for the other tests, but the data is also on the website in the description.
diversity should be built into the FC firmware. that way you could use entirely different systems, and none of them would have to change a thing.
hello ! there is a updated v1.1 flat antenna that is supposed to solve the range issues.
anyway thanks for the video, that's a lot of work you put in
We've received them and they are fixed. They're a little worse than the tower antenna but not by much. Approved for use, no longer garbage class
great content! i was wondering about the garbage class flat antenna!
Suprising results! Very informative video! Thank you !
not sure why I am just now discovering this channel.
I think that 1/4Y dipole wires direct soldered to the tiny Express LRS Rx pcb signal and gnd would be a decent and light antenna option too.
I heard that betafpv fixed something with the flat antenna?
Great testing!
That's correct! They have determined that there is a flaw in the first revision and will replace them if you bought one. The new ones are in the ballpark of the ceramic tower antennas, but slightly worse. Myself and three other developers have done testing and we're in discussion with BetaFPV about it. I'd say they're arguably usable now for LOS / Racing.
Nicely done comparison mate, awesome data! How do those matek whip antennas go that they bundle with their elrs stuff? Im wondering if i should use a betafpv dipole or the included whip for longer range.
Thanks! The Matek antennas are sleeved dipoles, or at least the ones I have are. You can tell if they are if they have a hard metal sleeve covered in the heatshrink before the active part of the antenna. They have pretty much the same range as the T-style dipoles within the margin of error, with the sleeved dipoles performing very slightly worse if the sleeve part isn't exposed causing them to detune a bit.
@@CapnBry ok cool, yeah I wasnt sure what was going on inside that heat shrink lol. I didn't want to destroy one to find out. As long as they're ok then I'm ok with them :)
thank you
I would love to see this test with the super D receiver.
No video, but here's the details.
ua-cam.com/users/postUgkx6d1z6Ii0bLVrIHCxSZZDzsJNMXkVMqfl
Thanks for testing. Now we know the facts. 👍. Not all, because I really wonder why the COM28 SIYI FM30 diversity performs not top range, you mentioned maybe a faulty LNA? I guess the Matek R24-D with a LNA: SE2431L will perform much better, should be the no.1 ? Is COM28 Axis dipole the same technology using as the HM EP1?
Thanks a lot for the Video and also for using metric system. Im looking for the best transmitter antenna for my Jumper T Pro since it comes with a N2420 airgain 2.4GHz antenna inside and Im not sure if its a good antenna or not
Thanks for sharing, that is great info!
I'm not getting the best range with my Express lrs so I need to do some of your antenna swaps
Thanks so much! I have always suspected this was the case but you've done the testing to confirm 😁. Ill keep making my own dipoles (T antennas). Just curious do you know if a sleeve performs the same as a T?
The data doesn't really back it up very strongly, but the sleeved dipoles seem to perform just slightly worse than the T-style dipoles but better than the monopole (just the wire itself). In practice it feeeeeels to me like the T perform better on my models but I would never be able to tell in a blind test.
Nice Video! I wish i had seen it before i ordered a bunch of those crappy receivers... 😑
very nice video thx
"Garbage Class" - can this become an official term? :D
"You know who you are" 🤭
There is very interresting video. Thank you. but i have a question. how can you make such measurements . i mean what hardware / software do you need ?
It is built into ExpressLRS master with the debug_rx_linkstats user define (or something like that). Several RX are connected to FTDI cables all connected to the same TX with telemetry turned off. The per-packet stats are then post processed in whatever graphing tool you want, we use jupyter now with pandas and seaborn.
@Bryan "CapnBry" Mayland thanks for quick reply. 👍
+1👍TYVM 💪
How do I know if a particular ELRS Rx has an LNA? For example does the Matek Elrs diversity 2.4g have an amplifier?
All the current diversity receivers have amplifiers. You can tell if a receiver has one by it having a third chip next to the antenna. It is also listed in the docs:
www.expresslrs.org/2.0/hardware/receiver-selection/
Did you measure noise floor before the test? Why is SNR so prevalent at these power levels? 10-11 dB at good signals? Something's wrong.
I don't really understand your question. SNR is prevalent? I can't tell if you're saying the SNR is too high or too low for what you're expecting.
@@CapnBry sorry, question is why SNR is always close to 10 dB pretty much all the time. Is it just that noisy? thanks for all the work and tests!
@@Onefgear The SNR is how high the signal is over the noise, so 10dB means the signal is over 8x stronger than the noise. Lora can receive in the range from +infinity down to around -3 (yup it can receive if the packet is actually weaker than the noise). So it is no surprise the SNR is almost always positive, because our signal is stronger that the noise.
@@CapnBry Thanks yes I know that. Simply curious why the noise is so high at those signal levels. Is the noise really that high? e.g. Data shows -30dBm with 10-11 dB SNR and so does dBm in the low -90s. Have you measured noise floor?
@@Onefgear oh because the dynamic range of the lora chip can't measure that far down. The reported SNR only can only get up to +12dB before the noise is too far away to compare.
Which actual RX models are these? (Esp. the BetaFPV winner!)
It is the ELRS Nano according to their website.
@@CapnBry Aha - thanks! I see where they mention the LNA. Very cool.
@@CapnBry the confusing part is that my BFPV ELRS nano RX came with T-Antenna; However, i do also see the PA+LNA chip in diagram.
@@nerdCopter the Nano cimes with the t antenna and amp. The Lite can be purchased with the red flattie antenna. The product naming is a bit confusing, but that's because TBS called their receiver the Nano so everybody has to start there sadly.
@@CapnBry got it, after re-watching i was clarified that #4 and #5 was the same RX, differing antennae only. i have nano. yes naming sucks :P