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        Discussion 5.8ghz 200mw range flight - record by futurebreeze 24km - video post 1281

#1 whakahere May 18, 2011 12:20 PM

5.8ghz 200mw range flight - record by futurebreeze 24km - video post 1281
 
3 Attachment(s)
Range with 5.8ghz 200mw is possible. While this thread started out as showing that range was possible it has changed to a general purpose thread on those that are looking to get extra range out of 5.8ghz.

Getting started
The general rule to get extra range from 5.8ghz is using circularly polarized antennas. These antennas can either be brought or made at home. Antennas used during my range attempts were a combination of high performance tuned antennas from Markus123456 and tutorial guides from IBCrazy (where you can also buy performance tune antennas).

Antennas
Proper antennas and their placement are the keys to successful 5.8ghz flight. As you see here we are using only 200mw of power. Generally circularly polarized (CP) antennas give the best performance. It is not to say linear can not give range but most will find it easier to achieve by using CP antennas. If you change from Linear to CP antennas remember to change both antennas on the video receiver (VRX) and the video transmitter (VTX). If you have linear one of while CP on the other it will effect your overall range and might not give the benefit you are looking for.

The first antenna you will need to get you hands on is a cloverleaf (CL). This antenna goes on your plane, i.e. the VTX. This antenna will remain on either short or long range flying.

The antenna on the VRX depends on the mission. There are a ton of antennas out there. TrueRC have a few antennas that can help with multipathing and of course there are the antennas from IBCrazy. For omni style flying on my planes I like to use a Skew-Planar Wheel (SPW). With a good layout and antennas I pushed it to 3km and markus123456 went 6km. For safe flying tuned antennas will give you 2km in a plane but so far the reports are much less in multicopters. The key to extra safe range is making sure one of the lobes is facing the front of you plane.

The CL and SPW are not overall hard to build but they are hard to tune. For best results with home builds use 0.6mm copper wire and measure as best you can. My home builds go out 1km clear but they don't get the overall range of tuned antennas. Homebuild antennas are great for crash and bashing. CP antennas don't like crashing as they can bend out of shape and this effects the performance. If you don't crash and like range then pony up for tuned antennas as it will be hard get the same range on homebuilds. For homebuilds the cable you need can be easily found on ebay or you can use part of the linear antennas you already have. Each brought cable gives you the chance to make 2 antennas.

For directional antennas when you are going for max range or have an antenna tracker a helical is a great choice. They are easy to build, IBCrazy has a tutorial and they are wide band which means you can getting a better signal across the whole frequency (and makes them easier to build). I use 1mm copper wire and copper coated printed circuit board for the base. A 5 or 6 tune gives the best beam width for flying but the best range can be had with a 8 turn.

Current Record
The current record is 24km by costi_n. video post 1281

Some discussions within the thread (more to come as I update)
Wifi frequencies around the world
I cooked my RC305 transmitter... fixable? or details in here

Other good 5.8ghz threads
Parkzone Ultra Micro FPV - 5.8ghz 200mw FPVhobby TX - 40g without lipo's :D
5.8Ghz

#2 BlueAngel2000 May 18, 2011 12:51 PM

Wow, really nice.
Congratulations.

Maybe your recorder does something to the video....
I would try that flight again, when the CL and SPW combo performs as good as the last time.
Maybe you have really damaged a little bit the rf module of the receiver, or at least introducing external noise via the rssi wire into the module.
I do use RSSI too on this receivers, but use a simple RSSI buffer (voltage follower) to decouple the rssi output off external noise.

Do you have some more pictures of the helical, especially the transformer.
Because i will build one too and haven't decided yet, which way to go with the transformer.
Alex does suggest the 75ohm coax (which i have at home) for 5,8G.

#3 whakahere May 18, 2011 01:04 PM

Quote:

Originally Posted by BlueAngel2000 (Post 18270446)
Wow, really nice.
Congratulations.

Maybe your recorder does something to the video....
I would try that flight again, when the CL and SPW combo performs as good as the last time.
Maybe you have really damaged a little bit the rf module of the receiver, or at least introducing external noise via the rssi wire into the module.
I do use RSSI too on this receivers, but use a simple RSSI buffer (voltage follower) to decouple the rssi output off external noise.

Do you have some more pictures of the helical, especially the transformer.
Because i will build one too and haven't decided yet, which way to go with the transformer.
Alex does suggest the 75ohm coax (which i have at home) for 5,8G.

I have no idea why it no longer shows rssi on two of my receivers that I hooked up. both no longer give any read outs for rssi. I removed the wire because It didn't work anymore. I have another receiver that runs on 5 volts that the rssi does come out still so I might do a test flight with that AND compare it to my current ones.

I just used a hecker transformer. have a look at my first picture and you can see it. I wish I could tune this antenna.

#4 vipix May 18, 2011 01:06 PM

Nice. I have same AV RX/TX and planing to extend range.
What RC radio do you use?

#5 IBCrazy May 18, 2011 01:13 PM

5.8GHz helicals are hard to match well. Thus they are not always very efficient and checking them requires some very expensive equipment. Thus I have been recommending the Hecker transformer match as it is the least prone to errors. I personally use it on 2.4GHz and 5.8GHz helicals. On 900MHz and 1280MHz, I use a tapered microstrip match. I am working on a block strip match as well which will be the easiest of all of them once I figure out how to do it correctly.

I have plans for a 5.8GHz CP patch. I have not been able to do anytesting yet, but I hope to do it soon.

-Alex

#6 whakahere May 18, 2011 01:35 PM

Quote:

Originally Posted by vipix (Post 18270557)
Nice. I have same AV RX/TX and planing to extend range.
What RC radio do you use?

I am using a futaba 9C with chainlink attached. I do need to fix the placement of a antenna on the RX as right now I have it pointing at the plane.


It looks like I screwed my RSSI on both transmitters. Neither of them give out any reading now. both are dead in that area :( I fear that I have damaged my 5.8ghz receivers. my other one which runs of 5 volts still gives a reading but I blew a cap on it one day when I plugged 12 volts into it :( I wish power was easier.

#7 whakahere May 18, 2011 01:37 PM

Quote:

Originally Posted by IBCrazy (Post 18270614)
5.8GHz helicals are hard to match well. Thus they are not always very efficient and checking them requires some very expensive equipment. Thus I have been recommending the Hecker transformer match as it is the least prone to errors. I personally use it on 2.4GHz and 5.8GHz helicals. On 900MHz and 1280MHz, I use a tapered microstrip match. I am working on a block strip match as well which will be the easiest of all of them once I figure out how to do it correctly.

I have plans for a 5.8GHz CP patch. I have not been able to do anytesting yet, but I hope to do it soon.

-Alex

I hope you can come up with some easy designs as I will build them. I have no expensive equipment because if I did I would most likely just blow them up anyway ;)

#8 NDw May 18, 2011 02:28 PM

The chainlink seems to be working well :)

Out of curiosity what voltages have you set the dosd rssi at?

#9 whakahere May 18, 2011 02:50 PM

Quote:

Originally Posted by NDw (Post 18271200)
The chainlink seems to be working well :)

Out of curiosity what voltages have you set the dosd rssi at?

um .... I used the setup wizard in the commander program. It did it for me. :D I have no idea and my plane is in the car ... ready to roll for testing after work tomorrow. This time I am taking my 5000ma battery AND all three of my receivers to test which one gives me the best picture over the same area on cloverleaf and SPW. Which ever one I deem the best will be going flying with a ton of battery and going the distance I hope. I am fixing my antenna now so it is upright on my RX.

#10 vipix May 18, 2011 03:59 PM

What is the best antenna on TX for helical on RX?

#11 whakahere May 18, 2011 04:09 PM

Quote:

Originally Posted by vipix (Post 18271931)
What is the best antenna on TX for helical on RX?

Well I am still testing so the best person to ask about the best antenna is IBCrazy as he has more knowledge in his pinky finger about this than I do altogether.

Of course the Helical has to go on you video receiver. It is like a patch antenna. My goal is to push this 6 turn as far as I can and then once I have seen the distance it can go I am going to build a 4 turn one for more close in flying. On my plane I am using a cloverleaf right now but I have no idea if the SPW might give me that extra bit of range. I guess there is two ways I could find out 1: test it or ask Alex (IBCrazy). One of my goals is to fly across the Rhine to the town across from me. There are some nice castles to fly over across that little stretch of water (1km wide).

I think overall after all this testing I most likely will use the cloverleaf and SPW for my main day to day flying on 5.8ghz. I like the omni feel of flying around me without having to worry about where the antenna is point at any given time. 5.8ghz is still mainly set up for short range flying right now but I am just interested to see how much I can push it. Part of the hobby.

Anyone can do what I am doing. I started flying a year ago (learnt to solder at this point too). got into FPV about 6 months ago. I have no electronic background .. I'm a primary school teacher :D

#12 rabe2000 May 18, 2011 04:20 PM

hey Whakahere, just congrats and respect !
Have the same tx/rx and made a testflight of 2,6 km today with cl and sw with really good video. but was too scared to go on, as flew with gopro and without groundrecording. so no gps-data for searching my SW, if things run bad.
must build the helical asap.

#13 cmanley_nl May 18, 2011 04:51 PM

Does that huge chunk of plastic around the original antenna (in your 2nd attachment) really have any purpose besides perhaps protecting the wire from being folded? I'm asking that because those thick antennas cause a relatively huge amount of drag on gliders.

#14 whakahere May 18, 2011 04:58 PM

Quote:

Originally Posted by cmanley_nl (Post 18272362)
Does that huge chunk of plastic around the original antenna (in your 2nd attachment) really have any purpose besides perhaps protecting the wire from being folded? I'm asking that because those thick antennas cause a relatively huge amount of drag on gliders.

I wouldn't think so. You could just take as much of that plastic off and use shrink tube to make it stronger .... or go the smarter way and just make yourself a Cloverleaf/SPW antenna with it. Then you could bank your plane all day while you drive up those thermals and not worry about any dropouts.

#15 cmanley_nl May 18, 2011 05:02 PM

Quote:

Originally Posted by whakahere (Post 18272408)
I wouldn't think so. You could just take as much of that plastic off and use shrink tube to make it stronger .... or go the smarter way and just make yourself a Cloverleaf/SPW antenna with it. Then you could bank your plane all day while you drive up those thermals and not worry about any dropouts.

I agree - a cloverleaf antenna would be most suitable (except on the smallest of gliders). I just found more info on the insides of rubber duckies: http://martybugs.net/wireless/rubberducky.cgi


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