900mhz Antenna Help DJI F550

[helloman1976]

I have a F550 hexacopter DJI knock off that sits on 6" legs. Currently I'm using a 900mhz 1.5MW transmitter and with the stock transmitter and, a Yagi 12dbi and 5dbi Omni wip on my ground station using the Eagle tree diversity controller I only get about 500 feet of range before it starts to break up pretty bad. I've heard many people say they have had similar problems with the stock transmitter antenna but I want to be sure before I throw money around. I found the 900mhz Bluebeam antennas by IBCrazy but they are rare in 900mhz and are rather large, I was told 6" across. Is there anything better? Is my range problem probably the stock transmitter antenna or is there something else I should check? I figured with diversity that my picture would get a lot better and it did get a little better but the range is still about the same. Thanks for your help and I'm new to the multicopter world as well as the multicopter forums.

 

[helloman1976]

Anyone?

 

[kloner]

900 is a problem with cp antennas, there 7 or 9" across, forget the exacts but there huge. the straight antenna should be working fine unless your changing the angle of the craft alot, like side to side or for and aft 40 degrees or more. if not, it's something else, usually interference from something

 

[helloman1976]

900 is a problem with cp antennas, there 7 or 9" across, forget the exacts but there huge. the straight antenna should be working fine unless your changing the angle of the craft alot, like side to side or for and aft 40 degrees or more. if not, it's something else, usually interference from something

Yeah I guess a CP antenna is out of the question then. What about a Vee antenna? It would be hard to mount and orient on a Hexacopter but I could get it done, would that help? Also, I went back and did some research. I'm running my video on channel 4 which is 1040Mhz and my antennas say they are tuned for 910mhz (890-940) which is channel 1. I feel stupid asking because I've tested all the channels but could this be it somehow? Channel 4 seems to be the clearest channel with no other changes to my setup, antennas etc. I do have a smaller 2dbi whip antenna that's dialed into 910mhz maybe I'll try that on the tranmitter but it's 2db and my main STOCK antenna is 3db I believe. I'm really struggling here because I really don't know enough about video transmission, wave propagation, the Fresnel effect etc etc. Thanks for the reply!

 

[kloner]

any antenna has a range. What would be more a problem is interference form stuff around you. try different channels and see if it's better. A sudden drop off is interference, especially close range... more so than an antenna problem is my main point. It;s most likely the craft and how it's setup

 

[helloman1976]

any antenna has a range. What would be more a problem is interference form stuff around you. try different channels and see if it's better. A sudden drop off is interference, especially close range... more so than an antenna problem is my main point. It;s most likely the craft and how it's setup

I went out flying yesterday and set my channel to 3 (1010mhz) on a supposed 910mhz setup (Yagi 12dbi and Omni 5dbi) and it was crystal clear for as far as I could go. I guess when I got away from the city the interference went away and the problem was gone. Now I'm wondering why my 910mhz antenna setup works better at 1010mhz? Any idea? I may upgrade to a 1.3Ghz setup or maybe go to the 5.8Ghz setup. What's your take on these, which one would you recommend? I see the 5.8Ghz antennas are super small but I dont want to use 5.8Ghz if everyone else is, know what I mean.

 

[helloman1976]

any antenna has a range. What would be more a problem is interference form stuff around you. try different channels and see if it's better. A sudden drop off is interference, especially close range... more so than an antenna problem is my main point. It;s most likely the craft and how it's setup

I want to become more mobile and do the whole backpack thing. I was thinking of getting this patch antenna in place of my Yagi antenna. Thoughts? Anything I should know? Thanks!

http://hobbywireless.com/index.php?main_page=product_info&cPath=73_74&products_id=9

 

[kloner]

those work, but they have a super narrow beam width.... if your flying off and can line yourself up with the flight it'd work. but a regular rubber duck will most likely be alot easier to deal with on both ends. it's 900, it just works. assuming this is a quad or whatever. yagi like you had is for long range fpv,,, miles away

 

[helloman1976]

those work, but they have a super narrow beam width.... if your flying off and can line yourself up with the flight it'd work. but a regular rubber duck will most likely be alot easier to deal with on both ends. it's 900, it just works. assuming this is a quad or whatever. yagi like you had is for long range fpv,,, miles away

I have a diversity controller so it selects the best signal. My 5dbi omni antenna is all I had before and I added the Yagi and that really, really cleared things up I just was not getting the range I was expecting. Now I want to change it up a bit and become more mobile. I was thinking of doing a "juz70" back pack and using my 5dbi omni and then pick up one of these 8dbi patch antennas for some range. The beam width on this one isn't that narrow at all unlike my Yagi. My Yagi is like 35 degrees horizontal by 35 degrees vertical whereas this patch would open up the sky for me even more at 75 degrees by 65 degrees horizontal and vertical. I'll probably keep my Yagi though because you are right, it does go a LONG distance if you ride the beam that is.

 

[kloner]

omni as in circular polarized? yagi is horizontal/vertical polarized. rubber duck and this patch you linked are hor/ver polarized. i bet the change was good. Was that before we found the bad reception part or whatever? revisit rubber duck on both end and see if that's working, it should. Then to increase range is the other antennas.

I fly an omni on the rig and crosshairs on the ground diverse. there 120 degree beam width so all out front and to my sides is covered. a rubber duck is 360 degree, just not much gain. in 2.4 the omni are 2" across so they fit easily

 

[helloman1976]

omni as in circular polarized? yagi is horizontal/vertical polarized. rubber duck and this patch you linked are hor/ver polarized. i bet the change was good. Was that before we found the bad reception part or whatever? revisit rubber duck on both end and see if that's working, it should. Then to increase range is the other antennas.

I fly an omni on the rig and crosshairs on the ground diverse. there 120 degree beam width so all out front and to my sides is covered. a rubber duck is 360 degree, just not much gain. in 2.4 the omni are 2" across so they fit easily

Omni as in omni-directional rubber duck whip style antenna (http://hobbywireless.com/index.php?main_page=product_info&cPath=73_74&products_id=45). I was thinking about a bi-quad or cosshairs but they seem pretty flimsy and being in a backpack might damage them, no? Also, do bi-quads and crosshairs have to be close to the ground plane? That's one thing I really like about Yagi's is they don't and the higher up the better but again I'm trying to be mobile now. I did find a 12" Yagi that claims to do 100 horizontal by 60 vertical. What do you think about this one? http://www.l-com.com/item.aspx?id=25682 It's small enough I could pack it in my backpack and put it on an extendable pole or something. I like the idea of the patch in the backpack through since the backpack can be placed on the ground and propped up and I hear a patch that's close to the ground works better, 6.5" for 900mhz is what I hear.

 

[kloner]

I'm unfamilliar with that linear plane stuff. I'm not sure if 4 feet up or 4" up makes a difference to anything

Mines a monitor on a tripod with a diversity receiver, DVR and a pair of 8db crosshair. It'd slide right into a backpack or even a sling like a gun..... mutli rotor in one hand, radio in the other. I drive but always have to walk in and this has been a perfect setup for me.

it also transmits the signal in 5.8 wirelessly for passengers. a fatshark with built in receiver within a mile can see the transmission

 

[helloman1976]

I'm unfamilliar with that linear plane stuff. I'm not sure if 4 feet up or 4" up makes a difference to anything

Mines a monitor on a tripod with a diversity receiver, DVR and a pair of 8db crosshair. It'd slide right into a backpack or even a sling like a gun..... mutli rotor in one hand, radio in the other. I drive but always have to walk in and this has been a perfect setup for me.

it also transmits the signal in 5.8 wirelessly for passengers. a fatshark with built in receiver within a mile can see the transmission

So with those 2 antennas and the diversity controller you should cover a good 180 degrees of horizontal sky and probably what 70 degrees vertical? Those should also benefit being closer to the ground as they are essentially "patch" panels and should work the best by being around 5-7 inches from the ground but I doubt it matters much as you are pretty "close in", less than 1 mile etc. With your setup you should get excellent range in 180 degrees I would imagine but flying behind yourself too far and you'll likely be blind. Is that what you experience? 5.8Ghz is great for long range LOS flying but terrible for punch through power.

I love 900mhz and the lower frequencies because I'm not affected much by trees or objects being in the way of my LOS. I flew out 1000 feet yesterday and I ended up behind a forest of trees and my LOS would have been literally looking through a line of 30-40 trees and some sand dunes to see my Hexa which was about 10 feet off the ground and I had perfect signal. I'm going to go ahead and pick up this 8" patch panel and see what happens from there. I think I'll keep my 5dbi rubber omni (vertical polarization) antenna and go from there. I do like your setup and I was thinking about doing that too only using 2 of these below, they have a 135 degree beam width. If I had 2 of these, I'd cover 270 degrees of the flying flied.

http://www.readymaderc.com/store/index.php?main_page=product_info&cPath=11_45_47&products_id=489

 

[kloner]

I fly 2.4 video on the craft to the diversity, then that transmits in 5.8 from the duo 2400 to a fatshark 5.8 200mw. those being mid gain have huge side and rear lobes. it's a killer 3-5 mile down low rig. can fly off to the sides a couple miles, mile behind it all....... but it's hard to get to the hole, and when i do, grab that handle and pivot so it's not anymore. it's a comftorable setup

The other part of this setup is a tracker, it also transmits in 5.8 out so it's all wireless. multiple monitors and goggles can watch in the pits at the same time. I get alot of riders

that is a 12db alot more directional crosshair. doesn't have the side lobes and rear coverage but doesn't need it. That usually goes up on the roof of my truck so nothing get's between it and it gives it an edge

dis is distance in feet and all of the first part is behind dirt. Watch the rssi go up, then it's not behind the dirt, but still behind trees. the water one is behind houses the whole time it's near em, but the crosshair and 2.4 lawmate gear blows through it

those are live feed captures, it's what was viewed during the flight

 

[helloman1976]

I fly 2.4 video on the craft to the diversity, then that transmits in 5.8 from the duo 2400 to a fatshark 5.8 200mw. those being mid gain have huge side and rear lobes. it's a killer 3-5 mile down low rig. can fly off to the sides a couple miles, mile behind it all....... but it's hard to get to the hole, and when i do, grab that handle and pivot so it's not anymore. it's a comftorable setup

The other part of this setup is a tracker, it also transmits in 5.8 out so it's all wireless. multiple monitors and goggles can watch in the pits at the same time. I get alot of riders

that is a 12db alot more directional crosshair. doesn't have the side lobes and rear coverage but doesn't need it. That usually goes up on the roof of my truck so nothing get's between it and it gives it an edge

dis is distance in feet and all of the first part is behind dirt. Watch the rssi go up, then it's not behind the dirt, but still behind trees. the water one is behind houses the whole time it's near em, but the crosshair and 2.4 lawmate gear blows through it

those are live feed captures, it's what was viewed during the flight

Wow, that is some amazing flying. I hope I can fly like that one of these days Very good signal, yes with the tracker adds a whole new world of range and clarity. I want to go as mobile as possible e.g., backpack in somewhere and shoot some video. I'm not digging dragging all this gear around and a tripod etc. I was on another forum today and I heard another guy say that his 900mhz system works best on 1010mhz which is channel 4, that's what I was experiencing also. I couldn't figure out why on channel 1 910mhz while using 910mhz tuned antennas why channel 4 1010mhz was far better and cleaner. Now I'm thinking maybe GSM 900mhz cellular band in city limits and then, when I left city limits I had gobs of range and clarity with no interference It seems to make sense that in the city I would have less range because of interference I guess. I'm trying to avoid going the antenna tracking route simply because of size even though I'll have the Eagle Tree Pro and I already have the Eagle Tree ground station, those two things combined gives you antenna tracking. Oh well, I have tons of flights coming up to get it worked out I guess.

 

[kloner]

your thoughts on a 910 antenna only being for 910 mhz isn't right. An antenna has a range of at least 500mhz,,,,, in 2.4 it's the same antenna used for 2310-2510,,, in 5.8 its the same antenna for 5680 as it is for 5940...... the tune isn't a big deal, what is the interference from stuff around you. Alot of not 3g phones use something in that range, emergency personel i think have radios in that range. the channel that works is regional depending where you live and what the city/county bought as gear

That tracker is all eagle tree, but i don't use it much. usually just that diversity with the pair of the same mid range crosshairs does everything LOS fine to 5 miles and that's plenty. That tracker would be more a 5-25 mile range rig for a high flyer or a super strong mid range setup for flying low behind stuff..........

So in a backpack setup, is usually goggles, where you gonna sit, the ground? got ants or is it ever cold? i'm too fat and old to get on the ground so standing is my natural prefrence. if so, you gonna drag along a chair? I'll make you a video today of how compact any setup is. Got kids to babysit, it'll give us something to do today

 

[helloman1976]

your thoughts on a 910 antenna only being for 910 mhz isn't right. An antenna has a range of at least 500mhz,,,,, in 2.4 it's the same antenna used for 2310-2510,,, in 5.8 its the same antenna for 5680 as it is for 5940...... the tune isn't a big deal, what is the interference from stuff around you. Alot of not 3g phones use something in that range, emergency personel i think have radios in that range. the channel that works is regional depending where you live and what the city/county bought as gear

That tracker is all eagle tree, but i don't use it much. usually just that diversity with the pair of the same mid range crosshairs does everything LOS fine to 5 miles and that's plenty. That tracker would be more a 5-25 mile range rig for a high flyer or a super strong mid range setup for flying low behind stuff..........

So in a backpack setup, is usually goggles, where you gonna sit, the ground? got ants or is it ever cold? i'm too fat and old to get on the ground so standing is my natural prefrence. if so, you gonna drag along a chair? I'll make you a video today of how compact any setup is. Got kids to babysit, it'll give us something to do today

Ok, good to know because my thoughts were that a 910mhz antenna, advertised as tuned for that frequency, would only be 910mhz. Channel 4 for me works best, 1010mhz so I guess that's what I'll use. I still haven't decided on what kind of antenna I'm going to get but I'll probably end up with that 8dbi patch antenna which I hear is pretty good when close to the ground. I'm still pretty fit and young, 36, so sitting on the ground is good for me. I was sitting on the beach just the other day flying at a state park and I was sitting up against a park sign. I prefer sitting, I can't fly standing as it jacks up my equilibrium for some reason. I get too immersed in what I'm doing and I all but stop breathing while I'm flying lol. I fly with my chin in my chest because early on I'd be flying and I'd see something interesting and I'd turn my head to look at it but my vision would not change and that really threw me off so I've trained to fly with my chin in my chest to remind me of what I'm doing. I've only had 14 flights ever and I still haven't had a crash. What's it take to be an Ace? Max range for me is probably going to be maybe a mile, I just want my signal to be so strong that I never lose video. I'm thinking the patch along with the omni and I should be good for that easy. The nice thing about the patch is that it's a 75 degree wide beam so it covers a lot of flying area.

 

[Bella7821]

I have the same issue as you but I got better range. on my 900 system I could go about 1/2 mile at work and about 30ft at home. But even at work the picture was never very clear.
I tried the stock whip antennas, Range Video Vee, IBCrazy's Vee and even his BiQuad for the RX.
Nothing worked and I had credit at Hobby King I had to use up so I went for 5.8 and spiroNet antennas and waiting for it to come in the mail.
Also bought a TBS Discovery so thing's can be spread out more

 

[kloner]

I found using a monitor made it alot easier to fly with because of a few things. You can look up and see what it's doing, where it's at etc. goggles might be fun to fly, but they hold you back imo because it seems like so much going on. When i started 6 months ago, i did gogles a few flights then bought a monitor and what a difference it made in getting better. i could see how high the model was zipping along and look at the monitor so knew what it looked like. then one day just made it stay like that longer and longer.

one thing i've learned if nothing else would apply to you is setup and where your at. You keep talking about the ant close to the ground, more important than that is whats out front of said ant. getting up on ridges and canyons yields crazy clean views and sitting down in a hole flying the canyon is the worse you can get.

 

[helloman1976]

I found using a monitor made it alot easier to fly with because of a few things. You can look up and see what it's doing, where it's at etc. goggles might be fun to fly, but they hold you back imo because it seems like so much going on. When i started 6 months ago, i did gogles a few flights then bought a monitor and what a difference it made in getting better. i could see how high the model was zipping along and look at the monitor so knew what it looked like. then one day just made it stay like that longer and longer.

one thing i've learned if nothing else would apply to you is setup and where your at. You keep talking about the ant close to the ground, more important than that is whats out front of said ant. getting up on ridges and canyons yields crazy clean views and sitting down in a hole flying the canyon is the worse you can get.

Very good to know and I hear with certain antennas you can use the mountains at your back to put up more gain, i.e. patch and panel antennas. Yes I agree and I always setup based on what my cleanest shot is and honestly I try to fly the beam as much as possible. I setup my shots, video and flight paths to be within the beam area of my best antenna. The patch should allow me a wide flying area and tons of range. I may one day go to antenna tracking and if I do I'll go with my Yagi and my patch in diversity and that'll be a 20 mile range setup. Either way, what really matters is that I only have 10 minutes of flight time so I can only go in one direction for maybe 4 minutes anyway. My real concern is can I safely fly 2 miles? If so, my Hexa and I are very happy. With all the extra power and gain I should have less trouble with obstacles and flying low.

As a hypothetical question, you mentioned flying in a canyon was the worst. What if you pointed your patch antenna into the canyon and then flew down into it? Should work as long as you dont get massive multipathing issues

Broke down and bought these 2 things...going to put the omni rubber duck on the transmitter and the patch is for the up-and-coming backpack.

http://hobbywireless.com/index.php?main_page=product_info&cPath=73_74&products_id=142

http://hobbywireless.com/index.php?main_page=product_info&cPath=73_74&products_id=9