Hey thanks a lot guys. I pretty much think I would have burnt out already in this hobby if not for this so wanted to share. To sit inside and have a little robot at your command sending you a beautiful live view of the world is pretty incredible if you think about it. I can see kids in the future looking back asking why did they have to stand outside??? Anyway, I still like to fly outside on nice days as well especially now that spring is here but ive already got a ton of flying this winter and that's why I love this setup.
Flying from inside house or car anyone?
- Thread starter Jeremiah Nelson
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For a person that said they will not respond anymore, you have been continuing to flood this thread with unsubstantiated personal accusations. In my vocabulary, that is trolling.
This forum is supposed to help people, to educate them and to share ideas, wether we agree with them or not. Jeremiah shared his setup which is definitely interesting. You on the other hand, have been consistently bashing me personally. You are missing the point of a forum: it is to educate. I guess that either you can't contribute anything or that you are only looking for bashing opportunities.
Let's keep the discussion on topic of radiation patterns, and antenna effectiveness in various setup.
I'm not going anywhere. I'm staying here to contribute, to educate, to share and to learn. You can decide to do as you wish.
Sent from my iPad using PhantomPilots mobile app
So I'm not going to read all 11 pages of point, counterpoint and the safety aspects of it. But if you did fly your drone like that from the inside, that is the true definition of a drone. Just ask Jihad John.
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Can we create a poster of these pearls?
I am sure at this point that you are going for the entertainment value. Add some bullying and offensive words and you have a winning formula with fanboys clicking frantically the like button.
You can checkout here. For anyone else interested in facts, continue reading.
Can't condense antenna theory in one post but some simple concepts can be presented:
1) antennas do not magnify the signal. They can't. What they can do is take some power and concentrate it in a particular direction. Compare this to light: A 1watt laser can reach a much further distance than a 1watt flashlight.
2) if the receiver and transmitter are fixed, it makes sense to use directional antennas as they can achieve a further range and there is no need for a wide transmission cone.
3) drone controllers use by default omnidirectional antennas because they have the widest coverage (almost spherical in shape) and will reach the drone in most of the space around the controller, within a given range.
4) higher gain omnidirectional antennas create a flatter sphere, like a doughnut, which result in an increased horizontal range at the expense of a reduced vertical range.
5) if the transmitter of a high gain omnidirectional antenna is always aimed at the drone (tracking it), the narrower vertical radiation pattern is irrelevant, however using statically mounted omnidirectional antenna means that the drone will not always be within the radiation cone. This is especially true for situations where the drone is close in distance but high in elevation.
6) fresnel zones, the term favored by hzl, are areas in which reflected signals due to objects within the radiation space, will interfere with the direct signal reaching the drone causing it to be mostly reduced (higher probability) or increased.
7) since we are flying drones, and the distance between the controller and drone is always changing, and since we do not have control over the location of obstructing objects, fresnel zones mostly deteriorate the signal. They can never be used as a mechanism to get a signal increased to the drone,
8) and finally, there is no relation whatsoever between the radiation pattern of an antenna which is a function of its shape, and between fresnel zones which are a function of the distance between the transmitter and the receiver, and their effect is a function of the above as well as the location of obstructing objects along the path.
Well, this sucks! I just received a call from L-com and they said its now out till June! When placed my order last week, they said 14 days. Now June?!?! Oh well, I cancelled it and am now looking for alternatives. If I can't find any by end of May, I'll just re-order HG2409MGU-RSP.
That realy sucks. You could get the one with an N connector and get 2 sma adapters. It wont hurt anything. In the house I have several adapters on each line and it would probably be better if I didn't but I stll get the range I want.
OK lets see if we can get to the bottom of WHY the OP's rig works inspite of "it cant "
comments posted earlier.
some initial factoids.. (a number of which you have stated)
1. Antennas both directional and omni exhibit gains depending on the fraction of a wavelength of the radiator presented, they dont add to power but they do gain efficiency by minimizing SWR and presenting more of the available rf signal in a given plane
or direction..
2. Lightbridge is a FULL duplex protocol ie both GCS and AC are both transmitting and receiving.
3. Lightbridge is based on Digital video protocols meant for digital cable(reportedly)
4. lightbridge makes use of FH and SS tech with extensive error recovery built into the protocol. UNLESS an error is severe enough to rise to interrupt comms its not logged... which also means that poor conditions are often masked to some degree..
5. the GCS TX and the AC both use MIMO .. similar to diversity but in both directions.
6. a small detail you perhaps didnt note in the picture by the OP in the P4 range leaderboard and in post #1 is that both of the Omni's were mounted on the sloping part of the roof
tilting the toroid rf pattern and if AC is flown in front of the car would boost the altitude of the radiation pattern in that direction ie a tilted toroid no longer quite an omni...
7 . IRL the toroid is FAR from perfect depending on the onmi radiator design..
it also tends to be fairly fat in the stacked quad omni designs
ie 5/8 wave dipole stood on end? slotted waveguides? quad stacked jpoles? Discone(no gain on that last)?
LOTS more possibilities.. SEVERAL antennas of complete different geometry exhibit remarkably similar radiation patterns..
in the case of the quad stacked assemblies a lobed pattern is most often noted...
and higher gain omnis tend to be of stacked design..
and pretty much ALL omnis unless a directional radiator is added facing straight up tend to have a signal null straight over the top of the antenna.
8. in the case of the WIFI you previously tried.. background noise levels on 2.4ghz
depending on time of day and locale could have been your issue..
I have punched WIFI between the island of Anguilla and Saint Marten at at their closest points with 23 db mesh dishes.. good solid link ,input power of .5 w. after signal path was established that way we then did the same experiment with 14db omnis mounted 30ft above ground level and again managed a good strong usable signal.
By the same token I have used 1W with a 14db yagi and could not even go 300yards
across a parking lot due to both fresnel zone obstructions/multipath interference and excessive 2.4ghz background noise desensing the receivers...
9. Lightbridge often has issues on certain channels if not using auto(manual or 24 channel mod) then the comms errors DO rise to the level of logging.
10. 2.4 ghz interference as stated above can be very time of day dependent..
ie municipal suburban testing mid day in often has 2-3 times the range in testing as compared to say 1800 when lots of folks home watching media over wifi and using the microwave oven...
11. near by strong 2.4 ghz noise even if NOT on the same exact freq WILL tend to desense the preamp in the RX .(microwave oven sources a chief culprit here)
12. both refraction and ducting effects have been noted in the 1-4ghz band ie atmospheric bending of the radiation pattern.
13.the Fresnel zones and obstructions are responsible for microwave fading at the receiver in response to out of phase signals/****** polarization..
14. MOST of the really LONG distance attempts are either conducted from cliffs/hilltops or over water at a reasonable height or over flat/open terrain ie an absence of objects poking into the signal path/fresnel zones, also conserves power to start off without much altitude gain being necessary...
this positioning benefits both directional radiators and omnis(taking into account the desense from same plane operations)(that cantilevered omni again)
15. Multipath reflections can be either interference OR valid signal depending..
generally NOT desirable..
16 .you have complete control over signal path obstructions when flying drones in long distance attempts see #14 above about minimizing fresnel zone obstructions in the attempts.
So How does the OP achieve the range in SPITE of what is commonly known??
the canted radiation pattern of the omni antennas is one key combined with the MIMO switching to the antenna/amp presenting the strongest signal path is another between the above 2 factors along with minimizing fresnel zone obstructions during the attempt and the lack of the resulting multipath reflections/out of phase signals arriving at the RX on either end(full duplex remember?) and the error correction laid over the top of all is MY theory for the OP's success.
(and its by NO means absolutely the answer just a working theory)
I will let all know AFTER the EVO amps get in and my TX is modded and I either go COTS for the omnis(have to buy 3 of them 1 for reversing/slicing apart to check design)
or I head for tech shop to fabricate locally(I have access to antenna analysis software and a hackRF..
ie best way to verify experimental results is to repeat/verify same besides I have a municipal gov/leo customer waiting on such a rig.
hzl
You can checkout here. For anyone else interested in facts, continue reading.
Can't condense antenna theory in one post but some simple concepts can be presented:
1) antennas do not magnify the signal. They can't. What they can do is take some power and concentrate it in a particular direction. Compare this to light: A 1watt laser can reach a much further distance than a 1watt flashlight.
2) if the receiver and transmitter are fixed, it makes sense to use directional antennas as they can achieve a further range and there is no need for a wide transmission cone.
3) drone controllers use by default omnidirectional antennas because they have the widest coverage (almost spherical in shape) and will reach the drone in most of the space around the controller, within a given range.
4) higher gain omnidirectional antennas create a flatter sphere, like a doughnut, which result in an increased horizontal range at the expense of a reduced vertical range.
5) if the transmitter of a high gain omnidirectional antenna is always aimed at the drone (tracking it), the narrower vertical radiation pattern is irrelevant, however using statically mounted omnidirectional antenna means that the drone will not always be within the radiation cone. This is especially true for situations where the drone is close in distance but high in elevation.
6) fresnel zones, the term favored by hzl, are areas in which reflected signals due to objects within the radiation space, will interfere with the direct signal reaching the drone causing it to be mostly reduced (higher probability) or increased.
7) since we are flying drones, and the distance between the controller and drone is always changing, and since we do not have control over the location of obstructing objects, fresnel zones mostly deteriorate the signal. They can never be used as a mechanism to get a signal increased to the drone,
8) and finally, there is no relation whatsoever between the radiation pattern of an antenna which is a function of its shape, and between fresnel zones which are a function of the distance between the transmitter and the receiver, and their effect is a function of the above as well as the location of obstructing objects along the path.[/QUOTE]
comments posted earlier.
some initial factoids.. (a number of which you have stated)
1. Antennas both directional and omni exhibit gains depending on the fraction of a wavelength of the radiator presented, they dont add to power but they do gain efficiency by minimizing SWR and presenting more of the available rf signal in a given plane
or direction..
2. Lightbridge is a FULL duplex protocol ie both GCS and AC are both transmitting and receiving.
3. Lightbridge is based on Digital video protocols meant for digital cable(reportedly)
4. lightbridge makes use of FH and SS tech with extensive error recovery built into the protocol. UNLESS an error is severe enough to rise to interrupt comms its not logged... which also means that poor conditions are often masked to some degree..
5. the GCS TX and the AC both use MIMO .. similar to diversity but in both directions.
6. a small detail you perhaps didnt note in the picture by the OP in the P4 range leaderboard and in post #1 is that both of the Omni's were mounted on the sloping part of the roof
tilting the toroid rf pattern and if AC is flown in front of the car would boost the altitude of the radiation pattern in that direction ie a tilted toroid no longer quite an omni...
7 . IRL the toroid is FAR from perfect depending on the onmi radiator design..
it also tends to be fairly fat in the stacked quad omni designs
ie 5/8 wave dipole stood on end? slotted waveguides? quad stacked jpoles? Discone(no gain on that last)?
LOTS more possibilities.. SEVERAL antennas of complete different geometry exhibit remarkably similar radiation patterns..
in the case of the quad stacked assemblies a lobed pattern is most often noted...
and higher gain omnis tend to be of stacked design..
and pretty much ALL omnis unless a directional radiator is added facing straight up tend to have a signal null straight over the top of the antenna.
8. in the case of the WIFI you previously tried.. background noise levels on 2.4ghz
depending on time of day and locale could have been your issue..
I have punched WIFI between the island of Anguilla and Saint Marten at at their closest points with 23 db mesh dishes.. good solid link ,input power of .5 w. after signal path was established that way we then did the same experiment with 14db omnis mounted 30ft above ground level and again managed a good strong usable signal.
By the same token I have used 1W with a 14db yagi and could not even go 300yards
across a parking lot due to both fresnel zone obstructions/multipath interference and excessive 2.4ghz background noise desensing the receivers...
9. Lightbridge often has issues on certain channels if not using auto(manual or 24 channel mod) then the comms errors DO rise to the level of logging.
10. 2.4 ghz interference as stated above can be very time of day dependent..
ie municipal suburban testing mid day in often has 2-3 times the range in testing as compared to say 1800 when lots of folks home watching media over wifi and using the microwave oven...
11. near by strong 2.4 ghz noise even if NOT on the same exact freq WILL tend to desense the preamp in the RX .(microwave oven sources a chief culprit here)
12. both refraction and ducting effects have been noted in the 1-4ghz band ie atmospheric bending of the radiation pattern.
13.the Fresnel zones and obstructions are responsible for microwave fading at the receiver in response to out of phase signals/****** polarization..
14. MOST of the really LONG distance attempts are either conducted from cliffs/hilltops or over water at a reasonable height or over flat/open terrain ie an absence of objects poking into the signal path/fresnel zones, also conserves power to start off without much altitude gain being necessary...
this positioning benefits both directional radiators and omnis(taking into account the desense from same plane operations)(that cantilevered omni again)
15. Multipath reflections can be either interference OR valid signal depending..
generally NOT desirable..
16 .you have complete control over signal path obstructions when flying drones in long distance attempts see #14 above about minimizing fresnel zone obstructions in the attempts.
So How does the OP achieve the range in SPITE of what is commonly known??
the canted radiation pattern of the omni antennas is one key combined with the MIMO switching to the antenna/amp presenting the strongest signal path is another between the above 2 factors along with minimizing fresnel zone obstructions during the attempt and the lack of the resulting multipath reflections/out of phase signals arriving at the RX on either end(full duplex remember?) and the error correction laid over the top of all is MY theory for the OP's success.
(and its by NO means absolutely the answer just a working theory)
I will let all know AFTER the EVO amps get in and my TX is modded and I either go COTS for the omnis(have to buy 3 of them 1 for reversing/slicing apart to check design)
or I head for tech shop to fabricate locally(I have access to antenna analysis software and a hackRF..
ie best way to verify experimental results is to repeat/verify same besides I have a municipal gov/leo customer waiting on such a rig.
hzl
You can checkout here. For anyone else interested in facts, continue reading.
Can't condense antenna theory in one post but some simple concepts can be presented:
1) antennas do not magnify the signal. They can't. What they can do is take some power and concentrate it in a particular direction. Compare this to light: A 1watt laser can reach a much further distance than a 1watt flashlight.
2) if the receiver and transmitter are fixed, it makes sense to use directional antennas as they can achieve a further range and there is no need for a wide transmission cone.
3) drone controllers use by default omnidirectional antennas because they have the widest coverage (almost spherical in shape) and will reach the drone in most of the space around the controller, within a given range.
4) higher gain omnidirectional antennas create a flatter sphere, like a doughnut, which result in an increased horizontal range at the expense of a reduced vertical range.
5) if the transmitter of a high gain omnidirectional antenna is always aimed at the drone (tracking it), the narrower vertical radiation pattern is irrelevant, however using statically mounted omnidirectional antenna means that the drone will not always be within the radiation cone. This is especially true for situations where the drone is close in distance but high in elevation.
6) fresnel zones, the term favored by hzl, are areas in which reflected signals due to objects within the radiation space, will interfere with the direct signal reaching the drone causing it to be mostly reduced (higher probability) or increased.
7) since we are flying drones, and the distance between the controller and drone is always changing, and since we do not have control over the location of obstructing objects, fresnel zones mostly deteriorate the signal. They can never be used as a mechanism to get a signal increased to the drone,
8) and finally, there is no relation whatsoever between the radiation pattern of an antenna which is a function of its shape, and between fresnel zones which are a function of the distance between the transmitter and the receiver, and their effect is a function of the above as well as the location of obstructing objects along the path.[/QUOTE]
Last edited:
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I never said that OP's rig will not work. I fully believe the distances he achieved.
I said that you can't fly outside of the radiation pattern of an antenna., and high gain antennas have a more focused beam meaning a much more vertically confined space of flight. I doubted his capability to fly high at close proximity of the controller, with a statically mounted omnidirectional antenna, as that would clearly be outside the radiation pattern.
***Argumentative Material Removed ***
I said that you can't fly outside of the radiation pattern of an antenna., and high gain antennas have a more focused beam meaning a much more vertically confined space of flight. I doubted his capability to fly high at close proximity of the controller, with a statically mounted omnidirectional antenna, as that would clearly be outside the radiation pattern.
***Argumentative Material Removed ***
Last edited by a moderator:
****Argumentative Material Removed ***
I suspect LCON as do the makers of nearly ALL high gain omnis are using a stacked quad configuration directional antennas joined by a phasing circuit , this means it more than likely exhibits a lobed pattern with the thickness of the lobes a bit thicker than the toroid formed by say a 5/8 wave vertical spike
ie near field is omni far field is lobed.
I suspect LCON as do the makers of nearly ALL high gain omnis are using a stacked quad configuration directional antennas joined by a phasing circuit , this means it more than likely exhibits a lobed pattern with the thickness of the lobes a bit thicker than the toroid formed by say a 5/8 wave vertical spike
ie near field is omni far field is lobed.
Last edited by a moderator:
You have both made all your points, can you guys call a truce so we can give the thread back to Jeremiah now?
ianwood
Taco Wrangler
The information is welcome. We very much appreciate the expertise. But we don't need the bickering. No more talk of trolling. Let's be respectful.
Back to the discussion...
Is there benefit to be had in raising the ground station antennas up on longer cable runs to improve the fresnel? I am trying to get maximum throughput in noisy environments all within 1/2 mile (mostly <1/4 mile). I've tried the DBS mod and the only difference it has made is to make the remote more directionally sensitive.
I am thinking of running some Sunhaus line amps with about 20ft of LMR400 to some 7dBi omnis (maybe 5dBi omnis) on top of a 15ft C stand. Antennas would both be vertical and about 2ft apart.
I think separating the 2.4 antennas will also help alleviate interference from the 5.8 TX in the second controller (Inspire setup).
Back to the discussion...
Is there benefit to be had in raising the ground station antennas up on longer cable runs to improve the fresnel? I am trying to get maximum throughput in noisy environments all within 1/2 mile (mostly <1/4 mile). I've tried the DBS mod and the only difference it has made is to make the remote more directionally sensitive.
I am thinking of running some Sunhaus line amps with about 20ft of LMR400 to some 7dBi omnis (maybe 5dBi omnis) on top of a 15ft C stand. Antennas would both be vertical and about 2ft apart.
I think separating the 2.4 antennas will also help alleviate interference from the 5.8 TX in the second controller (Inspire setup).
I would mount the sunhas amps on a short as possible length coax RIGHT at the antenna(s)...
then do the feed to the TX/RX through 2 longer runs of LMR-400
I would mount the antennas vertical BUT with a couple of wavelengths of vertical separation(12.5cm @2.4ghz) to avoid desense issues by mounting in the same horizontal plane.
hzl
then do the feed to the TX/RX through 2 longer runs of LMR-400
I would mount the antennas vertical BUT with a couple of wavelengths of vertical separation(12.5cm @2.4ghz) to avoid desense issues by mounting in the same horizontal plane.
hzl
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Thankfully, OP let us know what antenna he used: the LCOM HG2409MGU, and thankfully LCOM puts up a spec sheet with the radiation pattern of this antenna. So instead of guessing and inventing theories, here it is:
For those not familiar with radiation patterns, the horizontal graph is a top view, showing you distance while the vertical graph is a side view showing elevation.
There is zero radiation centered on the vertical axis. As a matter of fact, there is zero radiation within a (vertical) cone of 80 degrees (130 to 50)!!! In that area a signal cannot be received by the drone. You would have to tilt the antenna at leat 50 degrees to get the side lobe pointed upwards, or you would need a reflecting surface at the right location and angle to get any significant signal radiated up above the controller. Neither of those conditions exist.
****Argumentative Material Removed ***
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Meta4
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The moderators here don't get paid enough to stop fighting in the playground and clean up the mess.
Here's something from our community guidelines that a couple of members on this thread need to revise:
Here's something from our community guidelines that a couple of members on this thread need to revise:
Personal attacks on others will not be tolerated. Challenge others' points of view and opinions, but do so respectfully and thoughtfully. Excessive sarcasm, belligerence, insults, profanity, anger, offensive comments about race, gender, sexual orientation, religion, and national origin, are not acceptable.
I would like to get back on topic. I hope those of you the ordered the lcoms will post back with results of their setup.
Had to post this. I am sitting in my car having a nice flight in the park and these kids start doing crazy burnouts behind me. This goes on for a few min till the phantom 4 shows up! Sorry no sound. Ipad pro was throwing errors on export for some reason.
https://youtu.be/48As5hWFXjM
https://youtu.be/48As5hWFXjM
Awesome the one kid was freaking out for sure.
OK that was awesome. Talk about community patrol.
Is this the future? Haha. I can see this being done by the actual police force one day with "drones" worth 250K. BTW, every time I watch you fly its like a thrill ride and I wonder how long will your luck hold out. How often do you crash into stuff flying like that? You must go through props a lot. I do respect the skill and the courage!Similar threads
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