More car body is always way where you get more radio reception signal. Its same with CB radios etc in car. Put antenna middle back of car roof, and you get best signals from directly front of car. We used to track CB radios this way long time ago in Finland :)
I have a theory why going back had a slightly better signal. im thinking it wasnt where the antenna was located front to back on the car. but where it was located on the side considering that the stationary antenna was directional maybe that side of the road has a slightly better signal for a short distance.
I said to myself when you mounted the antenna on the car, "he's going to get better reception on the way back". It's because of the counterpoise (ground plane) or lump of electrically grounded metal around the whip. The metal on the car is attached to the antenna's ground, effectively making the car part of the antenna. So I thought you should have mounted it either dead center for a more omni-directional pattern or mount it centered all the way in the front of the car or the rear for a direction pattern. I was a radio engineer in the US Army many many moons ago. Also I think you may get a better range if you mount the yagi horizontal which will/should/may exploit an ionosphere bounce or reflections. maybe take a cheap telescope with you next time to see if you can see the transmitting antenna when the signal drops out. Those dropouts between 3k and 5k range may be do to reversed phase reflections.
Although he or other CZcamsr proven already to be able reach 30km range with this device, no modification, same type of antena. I believe he could do even better with a dish. Bouncing is not possible since 2.4GHz is same freqency as in microvawe oven, it's just absorbed by water molecules. Well nothing specific all frequencies are absorbed but all this trees leafs, bouncing from it, canceling. Longer the wave less terrain features is able to interfere. Still whatever he would do power is too small it's just physically impossible.
Im not sure how military do this. You dont have to struggle that much. You military people took all our freedoms all frequencies are available all power civilians do have only small band range, and laughably low power. It's very noisy absorbed by environment as if done on purpose. No matter what would you do it's just not enough power.. most of GSM, 3G, LTE nodes are 30-60W of power, to reach distance of just 2km. Why we are not allowed to use 1-10W devices? I dont understand. Most of GSM providers wont allow to use it for such purpose. LTE ping 50ms is still too much for a plane. Usable only to life stream camera unusable to send commands to quadcopter. It's miracle he was able to reach 6km no matter what. Im very surprised to see how NRF is actually one of greatest devices over there. And also very cheap. If we are allowed to have 1W, 10W of power, if we allowed to have for example 240-250MHz range or 24-25MHz not just 50kHz at 27Mhz, 10kHz wide band at 433Mhz so on.. we would not need to stand on our ears to do such things like remotely control toy.. hate military people just despise military people. Literally nazi Wietnam, Iraq, Syria, Ukraine.. all resources given to kill civilians with no reason. Yet people have to stand on ears to legally controll your harmless toys.
Just thought that I'd let you know that the "strange metal detector thing" is a plate measurer which you use to measure the amount of grass in your paddock so you know how much feed you have for your cows.
Not sure if any one has mentioned this. Yagi's have a front to back ratio. its hard to tell witch direction the antenna was pointing as you where driving away. if it was pointing to the front of the car your signal will be reduced. also turning the car is turning the antenna so it would be reasonable to loose signal. the height of the antenna above the car will also make a difference as the Yagi will interact with the roof of the car, similarly to ground plane, witch would destroy yagi properties. Also length of your coax and the coax types will also play a significant role on your range, the more power to the antenna the better. from the look at the coax in the video, it would have high loss @ 2.4Ghz, if you where looking to get as much range as possible, Try using a larger coax to the devices and keep the coax as short as possible.
It stops working when you approach houses, because you're getting Wi-Fi interference and the Signal to Noise ratio becomes too low, the receiver can'r properly demodulate the signal. Remember that with the nrf24l01 if there's a single bit error the CRC gets incorrect and the packet is discarded
Wifi routers are always sending many "beacon packets" per second, 20MHz wide, at the maximum tx power, prone to generate interference, especially if you have a LNA.
Beacon rate is typically less than 1kb per second though. If you look at the map of this area (www.google.co.nz/maps/@-37.5262887,175.5396064,299m/data=!3m1!1e3?hl=en) you can see there are only 11 houses over that 5km that are even a possibility for having wifi, and the strongest area of suspicious looking interference (at about 2.1km) is a couple hundred meters away from anything. I think in this environment wifi interference is negligible. You might be interested in another video like this I did in Tokyo which is of course much more densely populated with wifi all over the place (czcams.com/video/gtM832Z0ujE/video.html). Even in that situation I could still go 1km or so and still have decent signal even with trees in the way, using just plain old dipole antennas. There was however a very weak point along the way near houses which I attributed to wifi interference (see about 17:38).
Great to see your progress along on the videos iforce2d, I have been following for a while. I've also been watching some videos by a russian that has some very long fpv flights, perhaps you could look into his (or other) setups. Believe his channel is called "Long Range Quadcopter" Keep up the great work!
Those little yagi's are quite impressive!!! Here in the US, Ham's use a yagi and a hand held radio to contact the ISS circling the earth at approx. 200 miles on 5 watts . I used to fly light aircraft as a hobby, and as my altitude increased, so did the reception. I could hear other aircraft on the other side of the state if I got up high enough :-) (I'm also a ham radio operator) Interesting video, keep exploring :-) And, have fun!!!
Probably do better if the mount on the car was higher like the TX on the street sign. I don't know if the ground plane effect is as strong on a yagi type of antenna but on CB radio antennas the ground plane is very important from my experience many moons ago.
Not sure what antenna cable you are using on your fixed point, but you could have a significant amount of loss there. Try mounting the fixed end transmitter up on top right at the antenna, keeping the cable length to a minimum.
That's true. The antennas come with this long cable though and I didn't want to cut and (mess up) replace the plug. From the first test where 2.3km still had very good signal I figured it wasn't such a problem. It would be interesting to do it again with a minimum cable length and compare.
Doppler effect will ensure you always have better signal when traveling towards the transmitter, that's why cb antenna are usually mounted as close to the front of the vehicle as possible. It's well worth looking into as you can use the Doppler effect to maximize rf efficiency for both transmitter and receiver.
I'm afraid that doesn't make any sense at all. Radio waves travel at the speed of light, which is about 1,080,000,000 kilometers per hour, or around ten million times faster than my car. The difference in speed would only cause a shift in frequency of 0.000009% which is beyond negligible. Even if it wasn't negligible, how do we know the shift is in a direction that would be helpful, and why would we assume that any shift at all is helpful? Regarding the position of antennas on a car, if what you're saying is true then it would only help reception when driving towards the transmitter, and makes it worse when driving away from the transmitter... nobody wants that. If it's anything like GPS antennas, I think the best position for all-round reception from a CB antenna on a car would be on the roof, in the middle if possible. But in any case, Doppler effect on radio reception is nothing to be concerned about. Consider the Voyager 1 probe launched in 1977, which is now moving away from Earth at about 62,140 kilometers per hour and is still maintaining radio contact just fine.
I think having more of the metal roof in front of your antenna works better, because the metal roof is acting as a ground plane...some of .the signal is being reflected off of the roof towards the antenna...
Height can matter a lot. IIRC line of sight for two handheld units is about 5-6km before the curved earth starts to get in the way. If the terrain is not exactly flat the distance for line of sight is shorter. Top of the car is not too much higher than a hand held unit, the antenna at the pole is not significantly higher either. Rather sudden drop of signal makes me wonder if signal was blocked by curved earth perhaps.
The antenna cable of the transmitter is way too long! You have huge losses with this long cable. Shorten it to less than a meter and the results will be much better!
About your question what happening with getting better and less better signal as you drive is in "multi-pathing", that is multiple reflection of the road and all other objects. Although asphalt does not reflects much if signal is perpendicular, it reflects a lot when RF signal is almost parallel. At first you are getting higher frequency of "beat" by constructive and destructive interferences due to multi-pathing. If you wonder then, why you are getting different graph when you driving in one vs. other direction - it is because you are driving on different side of the road in both cases. For first my answer, I am 100% sure, because of many FPV flight, where 5.8 GHz showing it very clearly - exact behavior of the multipathing during flying in both directions. For second answer, I am also 100% sure. But, it is up to you to find it out. That means find day with least trafic (sunday maybe?), and mount antenna so that it is closer to the center of the road in both directions of driving car. This means that if you mount antenna say on right side of the car, when you coming back, mount antenna on opposite side, so that virtual position is about the same in respect to road.
I'm not so sure your second answer is right. I was driving pretty much in the middle of the road both ways - as you can see there is no traffic here :) I also doubt whether a few meters would make any difference at 5km away in this beam width.
Few meters at 5 km does not make any difference if there are no any conductor in vicinity. If for example some metal fence or grid or something, then few meters can make difference if whole thing (sum of all reflections) acting as a parabola, so few meters is like going in and out of focus.
Great video! could be really shorter though. As you not mentioned Fresnel, I will do. Line of sight works for lasers, but with 2.4 GHz RF you must take into account Fresnel Zone, which effects you met hard way after 5 km. Hope you can make another video where is no obstacles in Fresnel Zone Radius, so we would know how far those nRF24L01 really goes.
Very likely you are getting some amplification due to reflection from your roof within the beam width of that Yagi on the return trips. You'll get some of that as well on the rubber duckie antenna. You might get better performance on the rubber duck if you can mount the antenna mount at the apex of an inverted metal funnel, say 80 mm in diameter, or add some radials with a few pieces of solid copper wire and bend them down about 30 - 45 degrees from horizontal, to give that antenna a ground plane to work with. (I'm presuming that it's not a collinear in that length, if it is, you don't need to add a ground plane.) Aside from the power lines which may be affecting range, you may also want to do that drive with a wifi scanner w/o the nRF24L01 setup operating to see if you might be running into issues with wifi at peoples houses along the way. It might also be a good idea to scan the route with an sdr setup to see if there are any sources of other rf that might be interfearing.
Is it possible that, with more of the car in the 'field of view', that some of the signal is bouncing off the roof of the car up into the antenna? Just a crazy thought. Great video!
I wonder if having an altimeter working with the data @ the same time may have given a clue to the dips in signal. also, what if you ran the test going in the other direction? you mentioned @ one time you felt like you went over a small rise. that rise would have been a contributing factor to smaller rises that may have come up @ different parts of the drive. yes, altimeter & reverse test. get yerself out there again, young man! seriously - great test - interesting to watch all the way through! Russ from Coral Springs, Florida, usa
Interesting. These units are ~60 mW? Taranis outputs ~100mW from what I read, and the L9R receiver (2.4) is capable of reaching ~10km or more just with standard tx antenna and those little pcb rx antennas. Not sure what the data rate is, but your experiment seems to have reasonable expectations. Thanks for posting this video.
Couple of things, having more of your roof in front of the antenna on the return journey gives more of a ground plane for it, as has been alluded to below. If you had the Arduino etc. up at the top of the pole with the antenna the signal may be a little better, less losses due to the length of co-ax. Was there any feature on the road that could explain the peaks after the signal starts to break up? Does changing the yagi orientation from vertical to horizontal make any difference? Between Balladonia and Caiguna, the road stretches for 145.6 kilometers without a bend. This section of the highway, commonly known as the "90 Mile Straight", is regarded as the longest straight stretch of road in Australia and one of the longest in the world.
You should get into SDR, You can view different frequencies and protocols in depth with a single radio and even record a chunk of the spectrum to play back later.
I really doubt the Doppler effect has anything to do with it. The speed of light is 300 million meters per second. My car is only moving at about 14 meters per second :)
iforce2d Well I used to say the same just before we had to study that in university. Mobile towers compensate for it, moving on foot has little to no effect but in a car it becomes significant enough to cause connection drops.
power=10*log(100);power;loss=power+104-20+25+5~25;loss;pow(10,(loss-32.44-20*log(2400))/20)=15~157km f=2.4*10^9;d=5~15*10^9;r=8.657*sqrt(d/f);r=12~21m high to avoid fresnel zones
Whakahoro! You are driving on the wrong side of the road! :D I've a question about your hexacopter that you range tested a few videos ago. I don't wanna annoy you, but I wanna put something like that together. Please point me to a few places to get going. Thanks!
Hiya. I've come across an RFM69 chip on this site www.mysensors.org/build/connect_radio , while making an NRF24 module for my Taranis. What can the RFM69 chip do? Can it fly the toy quads? I've all the parts to make a module but I don't know what use it would be. If you've any information, that would be great. Thanks
lady with metal detector and clipboard looks like she may be a land or property assessor. property markers are usually big metal rods. then again u never know...
on wanting to try longer distance, check with you local airport club and see if there would be anyone interested in taking you up for a a flight to help with your experiment(you could pay for or split fuel or something).?.
Is the nRF24L01 a reliable transmitter/receiver when using in low range for example in a flat or does it interrupt sometimes and give false data? And does the signal pass thru walls?
It's radio, so yes of course it passes through walls, but the signal is also weakened by obstructions so the range will be decreased. If there are enough obstructions between the tx and rx then the transmission will be interrupted, but received packets will not give false data. The low-power PCB antenna type modules get about 80 meters range with no obstructions, so unless you have a really huge flat then those would probably be enough to cover it. It depends what type of walls you have and how many walls will be between the sending and receiving location. The only way to know for sure is to give it a try.
it appears you have harmonics in the reception. both places of poor reception and places of good reception. as for distance, since you have GPS, why not a boat ? as for the large metal reflector/collector between your receiving antenna and the transmitter.... why not take the side of a refrigerator to one of the distant locations with poor signals, and put it on a hinge. tilt it at different angels to see the effects.
By the way you can use this tiny & cheap cam(as recorder only, unless you hacks it somehow to transmit video! to show you what goes on with your quadcopter: www.banggood.com/SQ8-MINI-Camera-TF-Card-Voice-Recorder-Night-Vision-DV-Car-DVR-p-1022153.html
Everything is available in NZ if it can be posted :) If you mean is there a shop in NZ you can walk into and buy this stuff, never heard of that yet...
I like your video But my problem is different, I want to extend the range of wifi inside the building / house. I am developing home automation using wifi. There is no video on you tube , on this topic.
About 500 packets per second of 8 bytes should be possible, depends on antenna type, line of sight, and local noise. czcams.com/video/4XRp7pkZgPM/video.html
Just to clarify the 8 byte packets are just what I used for these tests. You can send packets up to 32 bytes in size though, my current distance record is about 35km for packets of 28 bytes or so, with regular whip antenna on transmitter and yagi on the ground (this is much much lower bandwidth though): czcams.com/video/o1J64naEEHY/video.html
@@iforce2d so, these might be good as sensor Nodes placed on the sides of volcanoes then? ...but there is Noooo danger of transmitting full HD video... - or audio....
2.3 kilometers is approx 1.4 miles, 10 kilometers is 6.2 miles and your steering wheel is on the wrong side of the car. Just in case my fellow Americans are watching. LOL
You forgot that he's driving on the wrong side of the road. Also he was swerving wildly like someone who's texting and driving. (I get he was trying to find the beam width, still every outside observer would say texting and driving.)
More car body is always way where you get more radio reception signal. Its same with CB radios etc in car. Put antenna middle back of car roof, and you get best signals from directly front of car. We used to track CB radios this way long time ago in Finland :)
I have a theory why going back had a slightly better signal. im thinking it wasnt where the antenna was located front to back on the car. but where it was located on the side considering that the stationary antenna was directional maybe that side of the road has a slightly better signal for a short distance.
I said to myself when you mounted the antenna on the car, "he's going to get better reception on the way back". It's because of the counterpoise (ground plane) or lump of electrically grounded metal around the whip. The metal on the car is attached to the antenna's ground, effectively making the car part of the antenna. So I thought you should have mounted it either dead center for a more omni-directional pattern or mount it centered all the way in the front of the car or the rear for a direction pattern. I was a radio engineer in the US Army many many moons ago. Also I think you may get a better range if you mount the yagi horizontal which will/should/may exploit an ionosphere bounce or reflections. maybe take a cheap telescope with you next time to see if you can see the transmitting antenna when the signal drops out. Those dropouts between 3k and 5k range may be do to reversed phase reflections.
Correction: At 2.4 GHz there is no ionospheric bounce, it's been a long time, ha ha, but I still think horizontal would give slightly better results.
Yes the ground plane is what I was thinking from my CB radio days.
Although he or other CZcamsr proven already to be able reach 30km range with this device, no modification, same type of antena. I believe he could do even better with a dish. Bouncing is not possible since 2.4GHz is same freqency as in microvawe oven, it's just absorbed by water molecules. Well nothing specific all frequencies are absorbed but all this trees leafs, bouncing from it, canceling. Longer the wave less terrain features is able to interfere. Still whatever he would do power is too small it's just physically impossible.
Im not sure how military do this. You dont have to struggle that much. You military people took all our freedoms all frequencies are available all power civilians do have only small band range, and laughably low power. It's very noisy absorbed by environment as if done on purpose. No matter what would you do it's just not enough power.. most of GSM, 3G, LTE nodes are 30-60W of power, to reach distance of just 2km. Why we are not allowed to use 1-10W devices? I dont understand. Most of GSM providers wont allow to use it for such purpose. LTE ping 50ms is still too much for a plane. Usable only to life stream camera unusable to send commands to quadcopter. It's miracle he was able to reach 6km no matter what. Im very surprised to see how NRF is actually one of greatest devices over there. And also very cheap. If we are allowed to have 1W, 10W of power, if we allowed to have for example 240-250MHz range or 24-25MHz not just 50kHz at 27Mhz, 10kHz wide band at 433Mhz so on.. we would not need to stand on our ears to do such things like remotely control toy.. hate military people just despise military people. Literally nazi Wietnam, Iraq, Syria, Ukraine.. all resources given to kill civilians with no reason. Yet people have to stand on ears to legally controll your harmless toys.
I would love to see this test repeated with 1 or 2 cheap 4 watt china wifi amps used. Also running the yagi's vertical polarization vs horizontal.
Just thought that I'd let you know that the "strange metal detector thing" is a plate measurer which you use to measure the amount of grass in your paddock so you know how much feed you have for your cows.
Perfectly normal in the middle of nowhere pasture areas I guess...
Not sure if any one has mentioned this. Yagi's have a front to back ratio. its hard to tell witch direction the antenna was pointing as you where driving away. if it was pointing to the front of the car your signal will be reduced. also turning the car is turning the antenna so it would be reasonable to loose signal. the height of the antenna above the car will also make a difference as the Yagi will interact with the roof of the car, similarly to ground plane, witch would destroy yagi properties. Also length of your coax and the coax types will also play a significant role on your range, the more power to the antenna the better. from the look at the coax in the video, it would have high loss @ 2.4Ghz, if you where looking to get as much range as possible, Try using a larger coax to the devices and keep the coax as short as possible.
It stops working when you approach houses, because you're getting Wi-Fi interference and the Signal to Noise ratio becomes too low, the receiver can'r properly demodulate the signal. Remember that with the nrf24l01 if there's a single bit error the CRC gets incorrect and the packet is discarded
Yes, assuming the houses have a 2.4g wifi running and it's busy doing something... in the middle of the day here that seems a bit unlikely though.
Wifi routers are always sending many "beacon packets" per second, 20MHz wide, at the maximum tx power, prone to generate interference, especially if you have a LNA.
Beacon rate is typically less than 1kb per second though. If you look at the map of this area (www.google.co.nz/maps/@-37.5262887,175.5396064,299m/data=!3m1!1e3?hl=en) you can see there are only 11 houses over that 5km that are even a possibility for having wifi, and the strongest area of suspicious looking interference (at about 2.1km) is a couple hundred meters away from anything. I think in this environment wifi interference is negligible. You might be interested in another video like this I did in Tokyo which is of course much more densely populated with wifi all over the place (czcams.com/video/gtM832Z0ujE/video.html). Even in that situation I could still go 1km or so and still have decent signal even with trees in the way, using just plain old dipole antennas. There was however a very weak point along the way near houses which I attributed to wifi interference (see about 17:38).
Great to see your progress along on the videos iforce2d, I have been following for a while.
I've also been watching some videos by a russian that has some very long fpv flights, perhaps you could look into his (or other) setups. Believe his channel is called "Long Range Quadcopter"
Keep up the great work!
I've just discovered your channel, very interesting stuff, keep up the good work!!
Those little yagi's are quite impressive!!! Here in the US, Ham's use a yagi and a hand held radio to contact the ISS circling the earth at approx. 200 miles on 5 watts . I used to fly light aircraft as a hobby, and as my altitude increased, so did the reception. I could hear other aircraft on the other side of the state if I got up high enough :-) (I'm also a ham radio operator) Interesting video, keep exploring :-) And, have fun!!!
The Apollo mission only used 5 watts and that was to the talk to and from the moon! They also used around the same frequency 2.2ghz.
This one: goo.gl/xti43o
Regarding car body in front of antenna: maybe it blocks (some of) the signal reflected off the ground?
Ehi man. Very good job...really. Thank you to share with us.
Probably do better if the mount on the car was higher like the TX on the street sign. I don't know if the ground plane effect is as strong on a yagi type of antenna but on CB radio antennas the ground plane is very important from my experience many moons ago.
Lloyd Prunier do you still CB? 26+27mhz or UHF?
Not sure what antenna cable you are using on your fixed point, but you could have a significant amount of loss there.
Try mounting the fixed end transmitter up on top right at the antenna, keeping the cable length to a minimum.
That's true. The antennas come with this long cable though and I didn't want to cut and (mess up) replace the plug. From the first test where 2.3km still had very good signal I figured it wasn't such a problem. It would be interesting to do it again with a minimum cable length and compare.
Doppler effect will ensure you always have better signal when traveling towards the transmitter, that's why cb antenna are usually mounted as close to the front of the vehicle as possible. It's well worth looking into as you can use the Doppler effect to maximize rf efficiency for both transmitter and receiver.
I'm afraid that doesn't make any sense at all. Radio waves travel at the speed of light, which is about 1,080,000,000 kilometers per hour, or around ten million times faster than my car. The difference in speed would only cause a shift in frequency of 0.000009% which is beyond negligible. Even if it wasn't negligible, how do we know the shift is in a direction that would be helpful, and why would we assume that any shift at all is helpful? Regarding the position of antennas on a car, if what you're saying is true then it would only help reception when driving towards the transmitter, and makes it worse when driving away from the transmitter... nobody wants that. If it's anything like GPS antennas, I think the best position for all-round reception from a CB antenna on a car would be on the roof, in the middle if possible.
But in any case, Doppler effect on radio reception is nothing to be concerned about. Consider the Voyager 1 probe launched in 1977, which is now moving away from Earth at about 62,140 kilometers per hour and is still maintaining radio contact just fine.
I think having more of the metal roof in front of your antenna works better, because the metal roof is acting as a ground plane...some of .the signal is being reflected off of the roof towards the antenna...
Height can matter a lot. IIRC line of sight for two handheld units is about 5-6km before the curved earth starts to get in the way. If the terrain is not exactly flat the distance for line of sight is shorter. Top of the car is not too much higher than a hand held unit, the antenna at the pole is not significantly higher either.
Rather sudden drop of signal makes me wonder if signal was blocked by curved earth perhaps.
The road is pretty lonely and frightens me. Especially the lady with metal detector. OMG
The antenna cable of the transmitter is way too long! You have huge losses with this long cable. Shorten it to less than a meter and the results will be much better!
Miroslav Petrov what‘s the max. length?
FYI signal reflects from the ground plane ..Using dual antennas on each side as a truck does will help you gather a wall of signal
About your question what happening with getting better and less better signal as you drive is in "multi-pathing", that is multiple reflection of the road and all other objects. Although asphalt does not reflects much if signal is perpendicular, it reflects a lot when RF signal is almost parallel. At first you are getting higher frequency of "beat" by constructive and destructive interferences due to multi-pathing. If you wonder then, why you are getting different graph when you driving in one vs. other direction - it is because you are driving on different side of the road in both cases. For first my answer, I am 100% sure, because of many FPV flight, where 5.8 GHz showing it very clearly - exact behavior of the multipathing during flying in both directions. For second answer, I am also 100% sure. But, it is up to you to find it out. That means find day with least trafic (sunday maybe?), and mount antenna so that it is closer to the center of the road in both directions of driving car. This means that if you mount antenna say on right side of the car, when you coming back, mount antenna on opposite side, so that virtual position is about the same in respect to road.
If you had real RSSI and signal just about the middle of the reading, you may get graph that resembles sinusoidal wave - without top-cut part.
I'm not so sure your second answer is right. I was driving pretty much in the middle of the road both ways - as you can see there is no traffic here :)
I also doubt whether a few meters would make any difference at 5km away in this beam width.
Few meters at 5 km does not make any difference if there are no any conductor in vicinity. If for example some metal fence or grid or something, then few meters can make difference if whole thing (sum of all reflections) acting as a parabola, so few meters is like going in and out of focus.
Great video! could be really shorter though. As you not mentioned Fresnel, I will do. Line of sight works for lasers, but with 2.4 GHz RF you must take into account Fresnel Zone, which effects you met hard way after 5 km. Hope you can make another video where is no obstacles in Fresnel Zone Radius, so we would know how far those nRF24L01 really goes.
Very likely you are getting some amplification due to reflection from your roof within the beam width of that Yagi on the return trips. You'll get some of that as well on the rubber duckie antenna. You might get better performance on the rubber duck if you can mount the antenna mount at the apex of an inverted metal funnel, say 80 mm in diameter, or add some radials with a few pieces of solid copper wire and bend them down about 30 - 45 degrees from horizontal, to give that antenna a ground plane to work with. (I'm presuming that it's not a collinear in that length, if it is, you don't need to add a ground plane.)
Aside from the power lines which may be affecting range, you may also want to do that drive with a wifi scanner w/o the nRF24L01 setup operating to see if you might be running into issues with wifi at peoples houses along the way. It might also be a good idea to scan the route with an sdr setup to see if there are any sources of other rf that might be interfearing.
The car body acts as a ground plane, and causes directional effects in the direction of the greatest ground plane area.
better signal inbound due to groundplane capacitive coupling of the car maybe??
Is it possible that, with more of the car in the 'field of view', that some of the signal is bouncing off the roof of the car up into the antenna? Just a crazy thought. Great video!
I wonder if having an altimeter working with the data @ the same time may have given a clue to the dips in signal. also, what if you ran the test going in the other direction? you mentioned @ one time you felt like you went over a small rise. that rise would have been a contributing factor to smaller rises that may have come up @ different parts of the drive. yes, altimeter & reverse test. get yerself out there again, young man!
seriously - great test - interesting to watch all the way through!
Russ from Coral Springs, Florida, usa
He did do the test in both directions, that's what the inward and outward was on the chart. He wasn't talking about inbound and outbound packets.
Interesting. These units are ~60 mW? Taranis outputs ~100mW from what I read, and the L9R receiver (2.4) is capable of reaching ~10km or more just with standard tx antenna and those little pcb rx antennas. Not sure what the data rate is, but your experiment seems to have reasonable expectations. Thanks for posting this video.
Couple of things, having more of your roof in front of the antenna on the return journey gives more of a ground plane for it, as has been alluded to below. If you had the Arduino etc. up at the top of the pole with the antenna the signal may be a little better, less losses due to the length of co-ax.
Was there any feature on the road that could explain the peaks after the signal starts to break up? Does changing the yagi orientation from vertical to horizontal make any difference?
Between Balladonia and Caiguna, the road stretches for 145.6 kilometers without a bend. This section of the highway, commonly known as the "90 Mile Straight", is regarded as the longest straight stretch of road in Australia and one of the longest in the world.
Come over to Tauranga and go to Mount Maunganui, heaps of clear parts to mount the transmitter and line of sight from as far as the kaimais haha
You should get into SDR, You can view different frequencies and protocols in depth with a single radio and even record a chunk of the spectrum to play back later.
My wild guess is that the car's roof acts as a reflecting surcafe, so the more effect is as you drive inward... bur that's just a guess
Gat a HGV-2404U antenna to do your test. Could you tell. l Whats is the radio module did you used?
The fact that your moving with a car introduces the Doppler effect too and these modules don't have a way to compensate like mobile towers do.
I really doubt the Doppler effect has anything to do with it. The speed of light is 300 million meters per second. My car is only moving at about 14 meters per second :)
iforce2d Well I used to say the same just before we had to study that in university. Mobile towers compensate for it, moving on foot has little to no effect but in a car it becomes significant enough to cause connection drops.
power=10*log(100);power;loss=power+104-20+25+5~25;loss;pow(10,(loss-32.44-20*log(2400))/20)=15~157km
f=2.4*10^9;d=5~15*10^9;r=8.657*sqrt(d/f);r=12~21m high to avoid fresnel zones
Maybe there is a doppler shift such that the pair are more closely matched in the return direction. Great work. ta
i'm in manawatu btw
Next gen Bose volume control
the irony of the straightest longest road name
Whakahoro! You are driving on the wrong side of the road! :D
I've a question about your hexacopter that you range tested a few videos ago. I don't wanna annoy you, but I wanna put something like that together. Please point me to a few places to get going. Thanks!
This might be somewhere to start github.com/iNavFlight/inav/wiki
Hiya. I've come across an RFM69 chip on this site www.mysensors.org/build/connect_radio , while making an NRF24 module for my Taranis. What can the RFM69 chip do? Can it fly the toy quads? I've all the parts to make a module but I don't know what use it would be. If you've any information, that would be great. Thanks
lady with metal detector and clipboard looks like she may be a land or property assessor. property markers are usually big metal rods. then again u never know...
awesome! this nrf24 is basically serial communication without worrying about rf?
the noise of the emf of the car and the car body (metal)absorbs ... consider that !!
on wanting to try longer distance, check with you local airport club and see if there would be anyone interested in taking you up for a a flight to help with your experiment(you could pay for or split fuel or something).?.
did you try the yagis in horizontal as well as vertical polarization ?
No
I was thinking the SAME thing! Plus I would have run the antenna much higher off the roof. At least two or more wavelengths.
Is the nRF24L01 a reliable transmitter/receiver when using in low range for example in a flat or does it interrupt sometimes and give false data?
And does the signal pass thru walls?
It's radio, so yes of course it passes through walls, but the signal is also weakened by obstructions so the range will be decreased. If there are enough obstructions between the tx and rx then the transmission will be interrupted, but received packets will not give false data.
The low-power PCB antenna type modules get about 80 meters range with no obstructions, so unless you have a really huge flat then those would probably be enough to cover it. It depends what type of walls you have and how many walls will be between the sending and receiving location. The only way to know for sure is to give it a try.
it appears you have harmonics in the reception. both places of poor reception and places of good reception.
as for distance, since you have GPS, why not a boat ?
as for the large metal reflector/collector between your receiving antenna and the transmitter....
why not take the side of a refrigerator to one of the distant locations with poor signals, and put it on a hinge. tilt it at different angels to see the effects.
What about a LNA ahead of the receiver? It would boost your range but, in some cases, it is likely to boost noise also.
I think there is a LNA in these modules: www.icstation.com/22dbm-100mw-nrf24l01ppalna-wireless-transmission-module-p-4677.html
Great work!! Thanks for it.
how to plot your graph from data? which software is used? Please enlighten me!
I'm using Libre Office Calc here, but pretty much any spreadsheet software eg. Microsoft Excel or Google Sheets should be able to make a basic graph.
i have nrf24l01 with antenna and i have one without antenna .. They can not communicate with each other
..
Should they be the same type
..
By the way you can use this tiny & cheap cam(as recorder only, unless you hacks it somehow to transmit video! to show you what goes on with your quadcopter:
www.banggood.com/SQ8-MINI-Camera-TF-Card-Voice-Recorder-Night-Vision-DV-Car-DVR-p-1022153.html
Do you have a link to the NRF24L01 and the larger antenna that are available in NZ?
Everything is available in NZ if it can be posted :)
If you mean is there a shop in NZ you can walk into and buy this stuff, never heard of that yet...
@@iforce2d ok thanks. Do you have a link or exact name of the larger antennas that you used for the NRF24s?
great testdrive !
Sounds like morse code
I'm wondering about that power line, would it be better on a road without one ?
I guess so, but try finding a road with all these requirements plus having no power lines :)
Arizona? "Jeej it worked!" *dies from dehydration*
That Yagi is never 25dB, it's 13dB at a push.
Hi, could you share your arduino source code? I have tested cheap nrf24l01 with PA and reached only about ~250 meters.
See the video description here: czcams.com/video/4XRp7pkZgPM/video.html
WiFi booster bro
sir i got some trouble wit my nrf24l01. when im not use antenna i got the data but if i use antenna my data not sent ?
Yovie Sigit *Is this on the TX or RX end?*
I like your video
But my problem is different, I want to extend the range of wifi inside the
building / house. I am developing home automation using wifi.
There is no video on you tube , on this topic.
@8:12 I used to live near there! Weird.
Hi! What about laws at this frequency and range?
1 Two none
lol I take it you dont have a wife..
Or maybe heh as a wife, but no job? That's how I do it. (live off savings)
i bud that and test it. its work only 10 meter
what sort of bandwidth are you pushing through there at 10km?
About 500 packets per second of 8 bytes should be possible, depends on antenna type, line of sight, and local noise.
czcams.com/video/4XRp7pkZgPM/video.html
Just to clarify the 8 byte packets are just what I used for these tests. You can send packets up to 32 bytes in size though, my current distance record is about 35km for packets of 28 bytes or so, with regular whip antenna on transmitter and yagi on the ground (this is much much lower bandwidth though): czcams.com/video/o1J64naEEHY/video.html
@@iforce2d so, these might be good as sensor Nodes placed on the sides of volcanoes then? ...but there is Noooo danger of transmitting full HD video... - or audio....
how to combine with i6
If you mean FlySky i6, they are completely different systems.
Ui orfe mijp moutho bueno kkkkkk
Ground plane
Can you send messages with this unit
You can send packets of up to 32 bytes, so if your messages are that long, then yes :)
2.3 kilometers is approx 1.4 miles, 10 kilometers is 6.2 miles and your steering wheel is on the wrong side of the car. Just in case my fellow Americans are watching. LOL
You forgot that he's driving on the wrong side of the road. Also he was swerving wildly like someone who's texting and driving. (I get he was trying to find the beam width, still every outside observer would say texting and driving.)
can you test with quad or airplan ?
I explained about that in the first 1 minute of the video