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sergio00

16,5 Kms VIDEO TEST 2.4ghz (10.25 miles)

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Today, me and 4 mates more, did a new range test to the 2,4Ghz video System.

In one field was 2 recivers systems ( Field Nº 2 ):

Standar lawmate reciver and a Jellow Jaket Diversity.

The Standar reciver had a 9 Dbi Omni antenna ( home made ) and in the Diversity reciver had a 14Dbi Patch and a 7Dbi omni. ( the patch was 8º vertical position )

In the other field an Easystar with 1W tx and 3dbi whip antenna ( Field Nº 1 ).

The distance between the 2 fileds was 16,5 Kilometers ( 10.25 miles )

Both groups was conected by telefone :P

Well,, we put the antennas watching the field Nº 1 ( compass was required).

The Easystar becomes to ascend doing circles ( FPV MODE).

All the time the Easystar was over the field Nº1

Well, we get Excelent video!!!!!!!!!!! Just when the airplane was above 300 mts altitude ( 984 feets) the video signal appears. ( low than that,, we hadn´t ).

Very good news!! So now we know that we can fligh 16,5 Kms without problem!!.

Video Quality: Was very good! The best image was in the PAtch antena. The Home made omni didnt was better than the patch.

In the diversity, the signal was in the patch all the time. ( it had a 7 Dbi omni and 14 dbi patch )

Conclusion:

1) we can fligh 16,5 kms with 1W Tx lawmate video without problem.

2) The Diversity Yellow Jacket work excelent in long range flights.

3) The best antenna was the 14 Dbi patch ( we hadn´t any 8dbi in the field to test it :( ).

4) like between the 2 fileds there are hills, was nescesary flight hight.

5) the Standar Range video reciver work well too.

6) The Antenna movement to this range, mut be low than 10º. If you move the antenna more than that, you will lose signal.

I show You a Fields satellite photos.

Thans to:

J. Carlos ( pilot )

Sergiona ( co-pilot )

Buitrago ( co-pilot )

Luico ( Standar Reciver )

And me jeje ( Diversity reciver )

SATELLITE IMAGE ( The BLUE LINE SHOW THE 16,5 Kms = 10.2531 miles)

165kmnx9.th.jpg

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wow!

It's very impressive, you still get good signal at that distance, it's good to know. I would be curious also to know if a 500mW tx can be receive clearly too, but probably yes because difference should be minimal if you receive a clear signal with 1W of power.

So the video link is not a problem, we just have to wait for Aeropix long range r/c transmitter/receiver in devellopement (Aerocomm) to have a chance to reach 10 miles and up with our r/c planes.

And then someone will need more power because he want to fly further...

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I've read that Thomas Scherrer of Intelligent Flight is already successfully flying at 10-20KM on average flight. :o I wonder how the boy genius did it? :o

Edited by JMS

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We will need larger fuel tanks. I have had high altitude dead stickNot because I ran out of fuel. Because the engine ran too rich over 5000 feet. So I tuned 3 clicks to go up high. Imagine flying from one field to another. Say have someone fuel your plane up and take off from there to return to home base to you ;) By the way thats great!

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HERE THE VIDEO:

Server 1: http://www.fileflyer.com/view/0SImrB0

server 2 http://files-upload.com/files/576056/16Kms...sVideoTest.divx

Divx is necessary.

I dint compress the video to show you the quality.

Now, watching the video in my computer, I note that the image is not so good like me and my mate saw in field. But I continue thinking that is good for 10,25 miles ( 16,5 kms away).

The day was very bad and windy. The Tx antenna wast in the best place, j.carlos put the antenna inside the model´s cockpit :confused:

We tested a rx signal amplificator too( i dont know the model becouse the owner was my mate Luico ). The image with the 12V amplifier was worst.

I heard that some aplifier works well, i would like the model to test it.

Would be nice if anybody do the same test with 900Mhz and 1.3 ghz systems to compare. :rolleyes: I cant do that becouse I have 2.4 only.

I hope with this video test, give my grain of sand to the FPV long range flights...

^_^

16kmslw3.th.jpg

Edited by sergio00

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Yeah you'd be happy to have an OSD showing home in these conditions, can't recognise a thing on the image.

RX preamps can work well indeed, but you need to be in a very clean and noise-free environment. Otherwise it's just worse with it than without. But it must have been clean at your location otherwise you wouldn't have had an image at that distance :P

That's the first time I see someone reporting comparable transmission as I'm used to since ages.

I get ~1500m with 10mW with a 8dB panel, 1W which is 100x more power should give 10x the distance, which fits pretty well in that case (OK, didn't count the difference of the 14dBi patch, but it's only a 2x difference where the usual reports are more like 10-20x difference with my results...)

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RX preamps can work well indeed, but you need to be in a very clean and noise-free environment. Otherwise it's just worse with it than without.

Yes for sure, the idea that its simple maths to double or treble your range is not correct !

If you take this idea to its limit you could keep adding amps and receive a 10mW signal 50 mile away but you cant.

Other noise will always get in, maybe it will be from the amp it self but most will come in through the aerial and this will limit what can be gained.

If you have a good first stage on you receiver you may find it makes things worse unless you have a long co-ax run.

Many year ago when I was into SSB it was normal practice to use an attenuator to kill the static and leave the wanted signal just audible. This way you get a quiet but clear signal and not a loud noisy one.

Terry

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RX preamps can work well indeed, but you need to be in a very clean and noise-free environment. Otherwise it's just worse with it than without. But it must have been clean at your location otherwise you wouldn't have had an image at that distance :P

I am agree with Kirlah , the preamps works bad if the source signal is very low. The preamps will put more noice in that conditions.

We tested that day a preamps with bad result ( 20 Dbm + - )

I heard that to get good preamps results, the preamps must be 10Dbm or less,, if you put a bigger preamps, you will put more noise.

The Power Tx and the distance insn´t linear performance you know that.

For example,, 1W is a 30% more range than 500mW just that.

I am agree with terry in this point.

Would be very interesting do the same test with 1,3 Ghz and 900 Mhz.

If anyone have those systems, please do that : :) to compare with 2.4 Mhz.

The main conclusion is that is possible 10,25 miles video flights ( speaking about the video only,, the rc is other theme.... ). And to get better security, an autotraking antenna is needed. 10º antenna movement is very few and is possible lose conection if you are alone an nobody can help you moving the antenna.

The antena was vertical, just 9 or 10º in horizontal plane

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The antena was vertical, just 9 or 10º in horizontal plane

At 10 miles assuming the ground is at the same level the angle will only be about 4 degrees even at 1000m high. So with a high gain aerial the beam is maybe 20 or 30 degrees vertical you would be about right to aim for 10 degrees but may get a better signal a bit lower. As you say the aerial needs to be set just right if you intend to fly out this far and you must fly perfectly down the beam :blink:

Terry

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Would be very interesting do the same test with 1,3 Ghz and 900 Mhz.

If anyone have those systems, please do that : :) to compare with 2.4 Mhz.

The antena was vertical, just 9 or 10º in horizontal plane

This Picture is a screen capture of 2.4 GHZ at 1000 mW lawmate video TX with standard 3 dBI rubber duck mounted vertically. Receiver was lawmate with 14 dBI patch worn on my helmet. Distance = 8 Miles Video was usable, but with noise and dropouts if antenna got moved at all.

post-5-1193779485_thumb.jpg

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This is a screen capture from a 500 mW latemate Transmitter on 900 MHZ at just over 8 miles. The transmitter antenna was a 3 dBI rubber duck mounted vertically. The receiver was the lawmate receiver with an 8 dBI patch sitting on the ground. ( Note - Sitting on the ground is the only way this patch would pick up a signal from this distance. ) The video was flyable but with noise and dropouts whenever the antenna was moved.

JettPilot

post-5-1193779765_thumb.jpg

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wow! EIGHT miles! That sounds so fun!

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