EVO II Antenna Range Tests

[Stillers]

Antenna	Type	Connector	Freq.	dBi	Range 1	Range 2	Range 3	Link
Autel SC Stock Antenna Blade	Omni	RP-SMA	2.4/5.8	unknown	11,941	12,433	12,618
Autel RC Stock Whip Antenna	Omni	RP-SMA	2.4	unknown	9,891	9,975	9,237
Generic Netgear Router Antenna	Omni	SMA	2.4/5.8	unknown	6,215	6,266	6,267
Unbranded Wifi Antenna Blade	Omni	RP-SMA	2.4/5.8	6dBi	10,991	12,139	11,679	6dBi Dual Band Omni-Directional WiFi Antenna
Kaunosta Wifi Whip Antenna	Omni	RP-SMA	2.4	22dBi	7,943	8,011	3,289	Kaunosta High Gain 22dbi Omni-Directional Antenna
Supertbat Wifi Whip Antenna	Omni	RP-SMA	2.4/5.8	12dBi	14,615	14,951	15,001	Superbat High Gain WiFi Antenna
Covert Drones/Titan Drones Whip	Omni	RP-SMA	2.4	9dBi	11,163	12,401	11,782	9 dBi Whip Antenna Kit
Covert Drones/Titan Drones 2.4G Directional Antenna	Directional	RP-SMA	2.4	22dBi	3,455	3,961	6,880	Titan 24/58
Covert Drones/Alientech Duo II	Directional	RP-SMA	2.4/5.8	28-30dBm	2,400	2,318	2,547	Alientech DUO II Amplified
Unbranded 4g/wifi Mobile Antenna	Omni	SMA	2.4/3g/4g	12dbI	4,022	3,911	4,386	12DBi 4G 3G 2.4G Omni Directional Antenna

Tests were ran one after another from mid-morning to early afternoon in excellent weather conditions of high 80s to low 90s in clear skies with no wind with relative humidity low. Flight path was over terrain with moderate elevation change beginning over urban setting but transitioning to rural setting approximately 4000 feet into flight. A small airport with no airspace restriction was located 500 feet south of the drones flight path around 6600 feet. ADS-B was active. Signal interference should be considered to be moderate to high.

https://imgur.com/aKkRE0r

The smart controllers position was static for eacy flight test mounted to a tripod and elevated 4 feet and angled 45 degrees for operation. Its geospatial location was in a residential neighborhood with significant tree and structures around, behind, and in front of the the cotroller including directly opstructing the LOS to the drone. Location was also nearby a commercial downtown area of a small community with the flight path going directly over it. []

Whip and blade antenna position was set to 90 degrees perpendicular to the horizon and connected directly to the controller with 90 degree adapters (when required).

Directional Antennas were attached via one 18 inch adapter cable. Antenna position was static via tripod and was mounted on top of a Pan/Tilt Head at approximately 5'6" elevation with the angle being adjusted regularly through flight to the angle estimated to be along the aircrafts trajectory.

Range was determined by running the same preprogrammed mission of flight in a straight line direction at 250 AGL at 22mph. Eastbound trajectory. The Range is defined as how many feet away from the takeoff location the drone was at when it lost communication with the controller and automatically began returning to home. I did not make any assessment of signal strength or account for when image degradation began in-flight. Of note is that the flight altitude was maintained along the same plane from start to finish but the drones altitude was not static. Due to dynamic terrain, the altitude varied greatly along the flight between 120 AGL and approximately 560 AGL. The controller was static at 0 AGL with the altitude at range 10,000 feet and on at 120 AGL.

Needless to say I am very disappointed with the Alientech Antennas performance. But, the Titan Drones directional antenna also grossly underperformed expectations so, being as I did no calculation of required angle and only estimated the best angle to aim the antenna, I will not rule out the possibility that I was wildly wrong in my estimation and neither antenna was aligned optimally towards the drone.

With the exception of the Netgear antennas and the mobile network antennas, it certainly seems that omnidirectional whip antennas are what the drone and controller seem to like the best. A dBi rating of 6-12dBi also seems optimal. It also does not seem that cost plays a factor nor does prestige of a name brand. The Kaunostica whip I am considering to be anomalous for a few reasons. One, Im suspicious of the 22dBi rating as I cannot find any peer competitor item for sale anywhere which also has an equivalent or similar dBi rating. Im skeptical that it is a unicorn item that only one company in the world manufacturers. Secondly, despite my suspicions of the dBi rating, Im leaving the possibility on the table that the dBi is accurate for the antenna and that I also was not able to properly align the antennas envelope with the drone just as I was not able to do with the directional antennas. That I also recorded one outlier result with these antennas as I did also with the Titan Directional antenna also supports this.

However if this is true, then that is a condemnation of the Alientech antenna as it recorded extremely consistent results on all 3 tests unlike the Kaunostica whips and Titan Directional. These results are also not consistent with its angle being manually adjusted arbitrarily. If the $10 Kaunosticas are legit, then that means the $500 boosted antenna is either defective, or junk.

If anyone is aware of how you can covert a powered antenna from using pcb-style directional panel antennas to RP-SMA outputs for whip antennas, I would love to hear about it. But I dont have much hope that it is. That being said:

For Sale Alientech Duo II Amplified Dual Band Antenna System. Like new, Less than 6 hours of flight. Still under manufacturer warranty. Comes with Smart Controller adapters. Retails for $525.00. Make an offer if interested

 

[herein2021]

Antenna	Type	Connector	Freq.	dBi	Range 1	Range 2	Range 3	Link
Autel SC Stock Antenna Blade	Omni	RP-SMA	2.4/5.8	unknown	11,941	12,433	12,618	View attachment 14367
Autel RC Stock Whip Antenna	Omni	RP-SMA	2.4	unknown	9,891	9,975	9,237	View attachment 14368
Generic Netgear Router Antenna	Omni	SMA	2.4/5.8	unknown	6,215	6,266	6,267
Unbranded Wifi Antenna Blade	Omni	RP-SMA	2.4/5.8	6dBi	10,991	12,139	11,679	6dBi Dual Band Omni-Directional WiFi Antenna
Kaunosta Wifi Whip Antenna	Omni	RP-SMA	2.4	22dBi	7,943	8,011	3,289	Kaunosta High Gain 22dbi Omni-Directional Antenna
Supertbat Wifi Whip Antenna	Omni	RP-SMA	2.4/5.8	12dBi	14,615	14,951	15,001	Superbat High Gain WiFi Antenna
Covert Drones/Titan Drones Whip	Omni	RP-SMA	2.4	9dBi	11,163	12,401	11,782	9 dBi Whip Antenna Kit
Covert Drones/Titan Drones 2.4G Directional Antenna	Directional	RP-SMA	2.4	22dBi	3,455	3,961	6,880	Titan 24/58
Covert Drones/Alientech Duo II	Directional	RP-SMA	2.4/5.8	28-30dBm	2,400	2,318	2,547	Alientech DUO II Amplified
Unbranded 4g/wifi Mobile Antenna	Omni	SMA	2.4/3g/4g	12dbI	4,022	3,911	4,386	12DBi 4G 3G 2.4G Omni Directional Antenna

Tests were ran one after another from mid-morning to early afternoon in excellent weather conditions of high 80s to low 90s in clear skies with no wind with relative humidity low. Flight path was over terrain with moderate elevation change beginning over urban setting but transitioning to rural setting approximately 4000 feet into flight. A small airport with no airspace restriction was located 500 feet south of the drones flight path around 6600 feet. ADS-B was active. Signal interference should be considered to be moderate to high.

https://imgur.com/aKkRE0r

The smart controllers position was static for eacy flight test mounted to a tripod and elevated 4 feet and angled 45 degrees for operation. Its geospatial location was in a residential neighborhood with significant tree and structures around, behind, and in front of the the cotroller including directly opstructing the LOS to the drone. Location was also nearby a commercial downtown area of a small community with the flight path going directly over it. []

Whip and blade antenna position was set to 90 degrees perpendicular to the horizon and connected directly to the controller with 90 degree adapters (when required).

Directional Antennas were attached via one 18 inch adapter cable. Antenna position was static via tripod and was mounted on top of a Pan/Tilt Head at approximately 5'6" elevation with the angle being adjusted regularly through flight to the angle estimated to be along the aircrafts trajectory.

Range was determined by running the same preprogrammed mission of flight in a straight line direction at 250 feet AGL at 22mph. Eastbound trajectory. The Range is defined as how many feet away from the takeoff location the drone was at when it lost communication with the controller and automatically began returning to home. I did not make any assessment of signal strength or account for when image degradation began in-flight. Of note is that the flight altitude was maintained along the same plane from start to finish but the drones altitude was not static. Due to dynamic terrain, the altitude varied greatly along the flight between 120 feet AGL and approximately 560 feet AGL. The controller was static at 250 AGL with the altitude at range 10,000 feet and on at 120 feet AGL.

Needless to say I am very disappointed with the Alientech Antennas performance. But, the Titan Drones directional antenna also grossly underperformed expectations so, being as I did no calculation of required angle and only estimated the best angle to aim the antenna, I will not rule out the possibility that I was wildly wrong in my estimation and neither antenna was aligned optimally towards the drone.

With the exception of the Netgear antennas and the mobile network antennas, it certainly seems that omnidirectional whip antennas are what the drone and controller seem to like the best. A dBi rating of 6-12dBi also seems optimal. It also does not seem that cost plays a factor nor does prestige of a name brand. The Kaunostica whip I am considering to be anomalous for a few reasons. One, Im suspicious of the 22dBi rating as I cannot find any peer competitor item for sale anywhere which also has an equivalent or similar dBi rating. Im skeptical that it is a unicorn item that only one company in the world manufacturers. Secondly, despite my suspicions of the dBi rating, Im leaving the possibility on the table that the dBi is accurate for the antenna and that I also was not able to properly align the antennas envelope with the drone just as I was not able to do with the directional antennas. That I also recorded one outlier result with these antennas as I did also with the Titan Directional antenna also supports this.

However if this is true, then that is a condemnation of the Alientech antenna as it recorded extremely consistent results on all 3 tests unlike the Kaunostica whips and Titan Directional. These results are also not consistent with its angle being manually adjusted arbitrarily. If the $10 Kaunosticas are legit, then that means the $500 boosted antenna is either defective, or junk.

If anyone is aware of how you can covert a powered antenna from using pcb-style directional panel antennas to RP-SMA outputs for whip antennas, I would love to hear about it. But I dont have much hope that it is. That being said:

For Sale Alientech Duo II Amplified Dual Band Antenna System. Like new, Less than 6 hours of flight. Still under manufacturer warranty. Comes with Smart Controller adapters. Retails for $525.00. Make an offer if interested

I would be curious to see how the stock non SC would perform under the same conditions. The reason I say that is because I have gotten around 27,000' with mine in a range test. My range test was absolutely perfect conditions though, 100' AGL over open ocean flying in a straight line with the stock controller.

Multiple times I have proven that in that scenario the only range limitation was the battery. I landed with 10% remaining after each test. At the 27,000' mark I still had video and full control over the aircraft, it could have gone further but due to battery concerns I turned around.

During one of the tests, the EVO II 6K was around 17,000' away and a person about 30' in front of me walked past the controller between me and the drone and the signal dropped to zero immediately; proving to me that even the slightest obstacle between the RC and the drone would make that range impossible to achieve.

 

[Stillers]

I would be curious to see how the stock non SC would perform under the same conditions. The reason I say that is because I have gotten around 27,000' with mine in a range test. My range test was absolutely perfect conditions though, 100' AGL over open ocean flying in a straight line with the stock controller.

Multiple times I have proven that in that scenario the only range limitation was the battery. I landed with 10% remaining after each test. At the 27,000' mark I still had video and full control over the aircraft, it could have gone further but due to battery concerns I turned around.

During one of the tests, the EVO II 6K was around 17,000' away and a person about 30' in front of me walked past the controller between me and the drone and the signal dropped to zero immediately; proving to me that even the slightest obstacle between the RC and the drone would make that range impossible to achieve.

Im positive that 17,000 wouldn't be a problem for a few of these antennas at all. I wasn't far off as it is and in my tests I had practically everything working against a long distance stable signal from the start in the form of 2 very large pine trees and a row of two story houses. The elevation drop off from my back yard to the next street down. Is great enough that both obstacles are probably only 30-50' above eye level but still obstruct LOS at the longer ranges.

There's 2 cell towers and one radio tower in the valley plus the airport. And no shortage of small aircraft in the vicinity. There's no airspace restriction over it but she gets quite a bit of traffic nonetheless. You gotta be careful flying east here but I wanted the additional obstacle for the test. And the fluctuating terrain itself is problematic. I really don't understand why but radio signals just seem to work better over flat land.

I think that may have played a part in the whip antennas clearly superior performance by nature of how its signal envelope is shaped enabling it to reach 'over' alot of problems. They certainly were doing something much, much more efficiently than the Directionals. That Alientech Duo should hsve done 4 times as much as it did. That was a real disappointment.

I think next I want to try one of those large bore, high gain pole-mounted OmniDirectional antennas and see if the trend of OmniDireftional antttnsd working so well.

 

[edgardcafe]

I would be curious to see how the stock non SC would perform under the same conditions. The reason I say that is because I have gotten around 27,000' with mine in a range test. My range test was absolutely perfect conditions though, 100' AGL over open ocean flying in a straight line with the stock controller.

Multiple times I have proven that in that scenario the only range limitation was the battery. I landed with 10% remaining after each test. At the 27,000' mark I still had video and full control over the aircraft, it could have gone further but due to battery concerns I turned around.

During one of the tests, the EVO II 6K was around 17,000' away and a person about 30' in front of me walked past the controller between me and the drone and the signal dropped to zero immediately; proving to me that even the slightest obstacle between the RC and the drone would make that range impossible to achieve.

Wow 27k.. I bet it wasn’t wind and you flew with ludicrous Mode back and forth. Have You used the SC (v1 or v2?) right ?

 

[Waldo Pepper]

If anyone is aware of how you can covert a powered antenna from using pcb-style directional panel antennas to RP-SMA outputs for whip antennas, I would love to hear about it. But I dont have much hope that it is. That being said:

If I understand this correctly, It is possible to change antennas on a powered antenna setup, I've done that before with different types of booster setups including controllers. Just remove antennas, resolder on connectors that whip antennas mount too. You'll need to open up the controller or booster setup, will try and post a picture or two of a recent Alientech booster setup I was experiencing with. Whip antennas are mounted outside front, it worked but for a particular drone I went back with different antennas.

Good luck, appreciate your hard work and effort to helping others.

Paul

 

[Waldo Pepper]

 

[Stillers]

If I understand this correctly, It is possible to change antennas on a powered antenna setup, I've done that before with different types of booster setups including controllers. Just remove antennas, resolder on connectors that whip antennas mount too. You'll need to open up the controller or booster setup, will try and post a picture or two of a recent Alientech booster setup I was experiencing with. Whip antennas are mounted outside front, it worked but for a particular drone I went back with different antennas.

Good luck, appreciate your hard work and effort to help others.

Paul

No problem, fella. Would definitely appreciate any insight you coild offer. If I cant figute out how to get results out of that Duo then it does me little good as. It is. As far as i can tell, any directional or. High gain antenna isnt much use at distance wighout an antenna. tracker and i dont know nothing about Arduinos and im not learning just to build one
Lol.

 

[Stillers]

View attachment 14369View attachment 14370

Ok mine is pretty similar to this one. The panel traces are a bit more elaborate but they appear to mount the same as these. Im assuming that a set of 5 or 6 pcb mount pins are soldered to the panels and run through a metal plate and connect to a integrated booster circuit?

 

[Waldo Pepper]

Ok mine is pretty similar to this one. The panel traces are a bit more elaborate but they appear to mount the same as these. Im assuming that a set of 5 or 6 pcb mount pins are soldered to the panels and run through a metal plate and connect to a integrated booster circuit?

Hello Stillers,

This particular booster in the attached pictures, is modified using a gutted Alientech booster housing, other parts from different models and the booster amplifies are from another brand originally made for Parrot. Recently tossed this together, Fortunately, these amplifiers have the correct connections to run whip or other antenna setups without soldering a connector. Extremely nice setup, but I changed it again recently and made it fit inside a skydio 2+ controller.

With the Alientech amplifiers, they need to be soldered on (hardwired) to add on connectors. I'm going to gut out another Alientech booster, a 5.8ghz model. It's worthless, somehow never could get it to operate correctly.

I'll attach a few pics, since I've changed it again making it even better and fits inside skydio 2+ controller.

Please keep us updated with your modifications, every bit of information from everyone will benefit all.

Happy Autel flying,
Paul

 

[herein2021]

Wow 27k.. I bet it wasn’t wind and you flew with ludicrous Mode back and forth. Have You used the SC (v1 or v2?) right ?

For the true long range tests I only fly in normal standard mode. Ludicrous drains the battery faster than it increases the range so the result is actually shorter range vs longer range. Drones are like everything else; there is an optimal cruising speed where you are getting the most distance per KWh used and anything past that and the wind resistance starts to eat into your remaining distance. For cars that's usually somewhere between 60MPH and 80MPH, for drones it seems to be around 23-24MPH.

I was tempted to use Ludicrous mode on the way back since it took so long to return, but I decided to play it safe and just wait it out vs risking running out of battery life. You are correct though, I would never try that on a windy day no matter which direction the wind was blowing.

During my testing I did find that around 17,000' out, it is safe to use Ludicrous mode to return with approximately 30-40% battery life remaining. Those were the good old days when I first got the EVO II 6K. These days the drone doesn't leave the ground unless its for a paying job and its usually in the air for no more than a few minutes.

 

[Stillers]

Hello Stillers,

This particular booster in the attached pictures, is modified using a gutted Alientech booster housing, other parts from different models and the booster amplifies are from another brand originally made for Parrot. Recently tossed this together, Fortunately, these amplifiers have the correct connections to run whip or other antenna setups without soldering a connector. Extremely nice setup, but I changed it again recently and made it fit inside a skydio 2+ controller.

With the Alientech amplifiers, they need to be soldered on (hardwired) to add on connectors. I'm going to gut out another Alientech booster, a 5.8ghz model. It's worthless, somehow never could get it to operate correctly.

I'll attach a few pics, since I've changed it again making it even better and fits inside skydio 2+ controller.

Please keep us updated with your modifications, every bit of information from everyone will benefit all.

Happy Autel flying,
PaulView attachment 14371View attachment 14372View attachment 14373View attachment 14374

Absolutely. For what I paid for it im gonna do some more trials with it to try and figure out if the device itself is faulty or just junk or if its something Im not doing right thats holding it back. And itll take me some time to study up on the technology and learn about it before I begin ripping into it. The first time I peeked inside I wondered if the amp panel could be integrated inside the smart controller directly but figured that was.a bit of an ambitious goal for a begginner in Amtenna Theory.

Have you worked with any of the Sunhans boosters? Are they worth the money they want for 4W dual frequency boosters? They sure are proud of them.

 

[Brock Inspector]

I appreciate your taking the time to conduct the tests and publish your results, Stillers.

My takeaway is that for flying legally within FAA Visual Line Of Sight, there is such a tremendous margin that if signal is lost it almost certainly will be from another cause besides subpar radiated signal strength using stock antennas.

For me, a stock keep-it-simple solution that's robust beats added complexity for day-to-day use (that's particularly so in a salt-water environ with antennas for the corrosion potential between dissimilar metals). Each additional cable length and cable connector contributes a parasitic loss in signal strength that multiplies (often disastrously so if crimp gets cronked or connectors aren't tight). The most elegant solutions often are the simplest ones, having the fewest number of parts.

Your data confirms what some of us may have long suspected-- a number of products get overhyped on the boards. What doesn't get enough mention is how very astounding the out-of-the-box radio range actually is.

 

[Stillers]

I appreciate your taking the time to conduct the tests and publish your results, Stillers.

My takeaway is that for flying legally within FAA Visual Line Of Sight, there is such a tremendous margin that if signal is lost it almost certainly will be from another cause besides subpar radiated signal strength using stock antennas.

For me, a stock keep-it-simple solution that's robust beats added complexity for day-to-day use (that's particularly so in a salt-water environ with antennas for the corrosion potential between dissimilar metals). Each additional cable length and cable connector contributes a parasitic loss in signal strength that multiplies (often disastrously so if crimp gets cronked or connectors aren't tight). The most elegant solutions often are the simplest ones, having the fewest number of parts.

Your data confirms what some of us may have long suspected-- a number of products get overhyped on the boards. What doesn't get enough mention is how very astounding the out-of-the-box radio range actually is.

Ill admit that I was impressed at the stock antennas ability compared to other options. But probably not as surprised as most would be that cost isnt an indicator of performance when it comes to antennas. At the end of the day, its just a piece of wire.

I dont think the Alientech has been overhyped, per se. I believe it may be a bit pricey, yes. But theyre not doing much about informing consumers on its proper usage. I think that if you mounted that antenna an automated antenna tracker that kept it dialed in so the drone was always flying within the antennas optimal envelope that that antenna, or any boosted directional most likely, would be able to project beyond the maximum distance possible for the drone to fly. Even on a one way flight. Ive rubbed elbows with some guys from the fixed wing rc community and have seen in action how surgical those antenna trackers can be. I watched a guy flying a gas powered rc plane at around 16 miles down range with an antenna that didnt look much more elaborate than the Titan 24/58.

I do agree with you that when it comes to antennas, K.I.S.S. Keep It Simple Stupid. No unnecessary cable or connections. No fancy setups. Do not add anything between the remote output and antenna input that does not have a proven benefit.

That being said, I do have a more elaborate setup Ive used and will use for situations that force having to fly in an area that signal is hindered more than usual. I have a Titan Drones Command Case Mini that can be affixed on top of a 20' Speaker stand/tripod. It requires a bit more cable lead than I like to connect the RC to the case but the Titan 9dB whips connect directly to the case and being able to put the boosters at the end of the string recovers any loss seen across the cable. Ive never range tested that setup like this because its just too differrent of a setup to have any comparative value. But i know for fact that I can see at least 19,000 on this setup. But, most significant isnt the range of this setup. The general increase in signal strength this setup provides is unbelievable. I would confidently say that adding just a little bit of height to the antenna position relative to the aircraft easily increases TX and RX reception by 50%-75%. Anytime I've had to set up that rig, I've had virtually no issues with degraded or pixelated video feeds nor do I have any issues with dropped connections. It also has alot more penetrating power than normal, it seems like. This could just be imagined instead of perceived but it seems to me that I can overcome more severe LOS obstructions and signal interference. But, Im not smart enough to be able to confirm these suspicions with data.

I fly this setup about half of the time for the reliability and safety of the added reception but I frequently perform 1A audits with drones in order to promote public awareness and reduce public fear of drones. Now, granted, I usually start off with the intention of getting the cops called but If you think people get uneasy when they see someone flying around them, then try setting up a tripod with an antennna on top and see how long it takes for the cops to show up. And then try explaining what it is to them without ending up in cuffs. Best just to keep it low profile during those flights.

For me, its not so much about the range and being able to fly beyond 2OK. Range is just an excellent measuring stick for an antennas performance. My interest in antenna performance is about reliability, not range. My home location and region I fly in are challenging for any one that wants to broadcast a radio signal reliably with any real range. We all know that anytime you hear "Remote Control Disconnected" that there is no guarantee that that feed will reconnect , thats never a fun experience when your waiiting for reconnection and just hoping your drone didn't fall out of the sky. My theory is that the less and less occurrences of Remote/aircraft disconnection I have will better my chances of not having a runaway or lost drone. I don't know how to quantify data on signal strength or rate the environmental difficulty added by different locations or how present it in an easily understandable way. So I use range as a measuring stick for antenna strength. Everyone understands footage.

 

[Brock Inspector]

c.2001, I set up a wireless data link over a Freewave one-watt, license-free spread-spectrum 900 MHz radio link with just Yagis at either end. Wasn't all that fast, but I lived at a mountaintop and this 27 mile shot gave me Internet for a couple of years after previously having none.
So last year I didn't first get why it was that Autel dropped support for 900 MHz/ 2.4 GHz dual band, to go with 2.4/5.8 GHz, given all this emphasis on max range. Most other non-US governments ban 900 MHz entirely or allocate as an RF band that's not license-free. But apparently 2.4 GHz won't so easily carry the data of a hi-def FPV video feed at high refresh rates, now that Autel has prioritized that with the Lite+ having such a 2.7K resolution video feed (seems to require 5.8 GHz, and distance limit of that res feed is 1KM). Not so much call for a radio control link any better than one that already outperforms the distance of your best video feed by 7:1

 

[Brock Inspector]

So the automatic tracking gimbal is somewhat intriguing for the Alientech if it really has that of narrow angle-of-acceptance (never have seen the degrees or dB gain) but that sure sounds like added complexity and yet another device requiring power management. But if I flew in high RFI environments, I'd want to know more. Links?

 

[Stillers]

So the automatic tracking gimbal is somewhat intriguing for the Alientech if it really has that of narrow angle-of-acceptance (never have seen the degrees or dB gain) but that sure sounds like added complexity and yet another device requiring power management. But if I flew in high RFI environments, I'd want to know more. Links?

The gain on the Alientech is 28-30 dBm. She's definitely tight.

If you need easy power in the field get on Amazon and search for Powkey power pack. 4 USB ports, 2 110AC outlets, and a 15V outlet driven by a 40,000mah battery. All the power you'll ever need in the field. If you do want more, then take a look at power stations. Those get into the thousands of watts and upwards of 90,000 mah. Some are even solar-ready.

This is one company that makes antenna trackers. There's a few others as well. I've seen them in action and they're pretty slick. I know a few guys that fly fixed wing RC gas-powered aircraft. The kind that can really get out there 15-20 miles if they want. These guys are playing with some very high gain, high power setups but no matter how far they get out, losing signal isn't a problem they have. Their antennas are mounted to antenna trackers and these things automatically adjust the antennas position so that its always aimed directly at the aircraft no matter where it goes. I dont understand the tech behind it but it sure seems to solve alot of problems with directional antennas.

I've read that you can diy these with an arduino but I wouldn't even know where to begin with that.

myflydream

myflydream

myflydream.com

 

[ne0031]

I stumbled across this post and thought I'd add some commentary. I've worked in microwave for a long time, designing and supporting both fixed and mobile operations. I'll admit that I have experimented with antennas on my controller and I'll explain why this doesn't yield the results most want.

Regarding the Kaunosta Wifi Whip Antenna... that is just funny. In an omni antenna, as you pass 9db of gain, the vertical radiation envelope of an axially radiator narrows to less than 6 degrees. "No one" makes "usable" 2.4 omnis with more than 15db of gain due to this. At 15db, the vertical envelope is less than 3 degrees. Did I mention that a 15db omni is also 5 feet tall?

I hadn't heard of any of the pieces you tested and I briefly looked at them while writing this.

I'll exclude discussion of 900 and stay on 2.4/5.8GHz. Both these bands are line of sight once you pass out of a near field area (where multipath can successfully bounce off nearby obstructions.) What this means is that once you pass a range of say 1,000 feet, you have transitioned to line of sight operations. I'll make some generalized comments, as I have not attempted to bench a controller and derive definitive loss/gain values. Most 2.4 systems, especially when transmitting video, use common encoders and have a base system gain of ~95db and final of ~130db. This means we have a nice, generic set of numbers to work with. I'm not intentionally ignoring the noise floor and will mention it later.

For reference, as distance doubles, loss quadruples, and 3db represents a doubling or halving of power. We'll use 2.4GHz for the following.... at 128 feet we have a free space path loss (fspl) of 70db, at 1024 feet 88db. Recall the ~95db figure from earlier - we are just 7db away, so let's go there. At 2,000 feet we've reached 94db of fspl.

Just to reiterate, I don't have the exact specs for Autel's transmitter or receiver. So what do we do? We get more range than this and they advertise a lot more. Let's add antennas. Given the drone has no external antenna and we've seen tear downs showing the strip line antennas in the arms, we'll assign an arbitrary value of 6db to them - I'll comment that this should only be on a direct axis, as the drone is rarely oriented with an antenna perfectly aimed at us....... we'll just assume.

We'll also assume the stock controller blades are 6db. In path loss, decibels are simply added and subtracted, thus the gain (add) on each end of the link means we went from 0 to 12db of margin. You can also state that the system gain has increased from 95 to 107db. This means that in theory, we can now move from 2,000 feet to 4,000 feet.

Now we can add transmit power. Common 2.4 systems support at least 18db, and if we add that we're now up to 125db of system gain. Getting close to that 130db of final gain aren't we? Range is now up to 32,000 feet. Wow, that's surprisingly close to the advertised 5.5 miles.

Given the testing that Stillers recorded, let's make some comments.

Amplifiers such at the Titan 24/58 are just that - amplifiers. They can't make something from nothing. If they were on both ends it would be fine, but they aren't. When you put a receive amp at the receiver, you have accomplished nothing. It can't amplify what it hasn't heard.

The Super Bat antennas are an acceptable size for the gain advertised (8db). They would give you a 3db increase over stock (assuming stock is 5db). Stillers listed them as 12db, and I saw that the gains was listed as 8, 11, and 12 in various places. For 2.4, it is 8db. Thus the very marginal range increase is "expected." These do have a narrow radiation envelope and would need to be oriented with a few degrees to realize any benefit "at range." Otherwise, you will see a reduction in range as the signal falls into a null (antenna speak for loss of gain.)

Methods to "make it better," use panel antennas. While these have a definitive orientation that must be observed, they are easier to aim and the radiation lobes are "easier" to imagine. A 19db panel is typically about a foot square with a 20 degree beamwidth. Once you pass 1,000 feet, they become relatively easy to aim. Since we have, in theory, a dual chain transmit/receive pair, we can assume one polarity will always align, thus no losses to deal with. Alternatively, the 4Hawks SR is an 8db panel with 90 degree beamwidth. Every time you halve or double the beamwidth, the signal is affected by 4 times (6db), thus it's easy to step from the 4Hawks SR to a "19" db panel... 8 db at 90d, 14db at 45d, 20db at 22degrees.

Finally, noise. In urban areas, the noise floor will be elevated and this results in a reduction of system margin. In a rural area, it is common to see noise floors of -95db or even lower, but in urban this can easily rise into the -70s and I've personally seen an area at -50. At that extreme level, flying more than a couple of hundred feet could be difficult.

I hope I've helped explain why "bigger" antennas aren't always better. The previous commentary about RC folks and the autoalignment systems is spot on.

 

[DocFlyboy89]

Has anyone ever tried installing a additional pair of stock antennas, but at the top of an elevated tower antenna, like the set up, I have, since I am a ham, radio operator, extra class. These are UHF frequencies and yes, directly installed from the SC then line of site rule, and if those antenna sitting at an elevation of 75 or 80 feet above the ground, obviously much better than five or 6 feet above ground in your hands from the smart controller. But as to which type of coaxial cable do utilize and the exact integration and coaxial cable set up and connections, I am not certain. Has anyone ever tried anything like this because to me that type of set up and lease from a homebase of operation as opposed to being out and about would give a significant improvement over anything else, except for his lack of mobility.

 

[ne0031]

Given that typical transmission line such as LMR400 has a loss of ~7db per 100', using a remote antenna at say 20 or 30 feet is certainly plausible. Yes, you'd have an additional 2db of loss, however, eliminating obstructions between may well be worth it.

I've used a 10 foot jumper between a tripod mounted antenna and the controller. No reason why it wouldn't work.

 

[herein2021]

I stumbled across this post and thought I'd add some commentary. I've worked in microwave for a long time, designing and supporting both fixed and mobile operations. I'll admit that I have experimented with antennas on my controller and I'll explain why this doesn't yield the results most want.

Regarding the Kaunosta Wifi Whip Antenna... that is just funny. In an omni antenna, as you pass 9db of gain, the vertical radiation envelope of an axially radiator narrows to less than 6 degrees. "No one" makes "usable" 2.4 omnis with more than 15db of gain due to this. At 15db, the vertical envelope is less than 3 degrees. Did I mention that a 15db omni is also 5 feet tall?

I hadn't heard of any of the pieces you tested and I briefly looked at them while writing this.

I'll exclude discussion of 900 and stay on 2.4/5.8GHz. Both these bands are line of sight once you pass out of a near field area (where multipath can successfully bounce off nearby obstructions.) What this means is that once you pass a range of say 1,000 feet, you have transitioned to line of sight operations. I'll make some generalized comments, as I have not attempted to bench a controller and derive definitive loss/gain values. Most 2.4 systems, especially when transmitting video, use common encoders and have a base system gain of ~95db and final of ~130db. This means we have a nice, generic set of numbers to work with. I'm not intentionally ignoring the noise floor and will mention it later.

For reference, as distance doubles, loss quadruples, and 3db represents a doubling or halving of power. We'll use 2.4GHz for the following.... at 128 feet we have a free space path loss (fspl) of 70db, at 1024 feet 88db. Recall the ~95db figure from earlier - we are just 7db away, so let's go there. At 2,000 feet we've reached 94db of fspl.

Just to reiterate, I don't have the exact specs for Autel's transmitter or receiver. So what do we do? We get more range than this and they advertise a lot more. Let's add antennas. Given the drone has no external antenna and we've seen tear downs showing the strip line antennas in the arms, we'll assign an arbitrary value of 6db to them - I'll comment that this should only be on a direct axis, as the drone is rarely oriented with an antenna perfectly aimed at us....... we'll just assume.

We'll also assume the stock controller blades are 6db. In path loss, decibels are simply added and subtracted, thus the gain (add) on each end of the link means we went from 0 to 12db of margin. You can also state that the system gain has increased from 95 to 107db. This means that in theory, we can now move from 2,000 feet to 4,000 feet.

Now we can add transmit power. Common 2.4 systems support at least 18db, and if we add that we're now up to 125db of system gain. Getting close to that 130db of final gain aren't we? Range is now up to 32,000 feet. Wow, that's surprisingly close to the advertised 5.5 miles.

Given the testing that Stillers recorded, let's make some comments.

Amplifiers such at the Titan 24/58 are just that - amplifiers. They can't make something from nothing. If they were on both ends it would be fine, but they aren't. When you put a receive amp at the receiver, you have accomplished nothing. It can't amplify what it hasn't heard.

The Super Bat antennas are an acceptable size for the gain advertised (8db). They would give you a 3db increase over stock (assuming stock is 5db). Stillers listed them as 12db, and I saw that the gains was listed as 8, 11, and 12 in various places. For 2.4, it is 8db. Thus the very marginal range increase is "expected." These do have a narrow radiation envelope and would need to be oriented with a few degrees to realize any benefit "at range." Otherwise, you will see a reduction in range as the signal falls into a null (antenna speak for loss of gain.)

Methods to "make it better," use panel antennas. While these have a definitive orientation that must be observed, they are easier to aim and the radiation lobes are "easier" to imagine. A 19db panel is typically about a foot square with a 20 degree beamwidth. Once you pass 1,000 feet, they become relatively easy to aim. Since we have, in theory, a dual chain transmit/receive pair, we can assume one polarity will always align, thus no losses to deal with. Alternatively, the 4Hawks SR is an 8db panel with 90 degree beamwidth. Every time you halve or double the beamwidth, the signal is affected by 4 times (6db), thus it's easy to step from the 4Hawks SR to a "19" db panel... 8 db at 90d, 14db at 45d, 20db at 22degrees.

Finally, noise. In urban areas, the noise floor will be elevated and this results in a reduction of system margin. In a rural area, it is common to see noise floors of -95db or even lower, but in urban this can easily rise into the -70s and I've personally seen an area at -50. At that extreme level, flying more than a couple of hundred feet could be difficult.

I hope I've helped explain why "bigger" antennas aren't always better. The previous commentary about RC folks and the autoalignment systems is spot on.

I know very little regarding the figures that you quoted so I will definitely defer to the experts for that; but in plain layman's terms it sounds like to me that your post confirms my suspicions; that most of these aftermarket "range boosting" antennas are pretty much useless and provide marginal if any benefit while simultaneously adding complexity to the kit.