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Wavess

Wireless AV & Water

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Today I went to another site to do some FPV. It´s a beutiful place a small lake and a very humid area. The signal coming just 20 or 30 mts away was very bad. I managed too hard with the plane cause I couldn´t see almost anything. If I went far away from the lake the picture was better but not enough though. My setup is exactly the same as always.

Somebody else has tried fpv with water presence?

Edited by Wavess

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Yes, I've been flying numerous times near or over water, both lake and sea. Never seen a difference. Was the surrounding air feeling especially humid?

Those were taken at ~550m AGL, as you can see LOTS of water all around :P

http://i18.photobucket.com/albums/b105/Kil.../PICT0823_t.jpg

http://i18.photobucket.com/albums/b105/Kil.../PICT0816_t.jpg

http://i18.photobucket.com/albums/b105/Kil.../PICT0815_t.jpg

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Minolta Dimage G400. I have always found it especially good for its class, knowing I've bought it at a very good price 3 years ago. Several friends had later bought newer models with lower quality and fewer settings for twice the price. This one has fully manual controls. When I changed for a bridge that has a 36-423mm equivalent zoom, I just couldn't let it go and thus converted it for AP with an electronic shutter. I still prefer it in certain conditions.

A friend got an HP camera especially for that purpose, but even in full daylight conditions we've never managed to get more than 10% good pics with it each flight, always blurry even with manual focus on infinity. With the G400 I get 90% good ones...

Its only flaw is the lack of video output :(

A couple more:

http://i18.photobucket.com/albums/b105/Kil.../PICT2757_t.jpg

http://i18.photobucket.com/albums/b105/Kil.../PICT3145_t.jpg

And some photoshop on one of the above: :P

http://i18.photobucket.com/albums/b105/Kil.../PICT0805_t.jpg

Edited by Kilrah

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Well, here is a sample video

FPV & Water

I have reencoded only a small part of it, the pixels you see is the bad quality I got, very strange. I review and compare with other videos and I apreciate lower quality even when I´m setting up all the stuff (2 mts away from the antenna)

P.D. Very beatiful pictures there Kilrah, the last one specially <_<

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Video looked as if there was another TX on the frequency, did you try changing channels ?

Terry

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Yes, looks a bit like a fixed image transmitted on the same freq. Is that a place you've already gone to? There could be a surveillance cam in the building you were above when it was the worst.

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Video looked as if there was another TX on the frequency, did you try changing channels ?

No I didn´t try to change channels because when I landed started a heavier rain.

Yes, looks a bit like a fixed image transmitted on the same freq. Is that a place you've already gone to? There could be a surveillance cam in the building you were above when it was the worst.

No it was the first time I went there, it has a beautiful landscape. The building when it gets worst it´s supossed to be a farm for the spanish bulls that are on the field behind. There´s also a busy road on the lake´s side, and I suppose almost every car has its mobile bluetooh on.

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Bluetooth will only give you random horizontal white lines here and there, not continuous static like this. And that's if it's less than a few meters of your RX antenna.

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It may not have been another TX it's just that's what the pattern looked like to me.

Have you used the system since the problem flight ? It maybe something else but I don't think it was linked to the water.

Terry

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It may not have been another TX it's just that's what the pattern looked like to me.

Have you used the system since the problem flight ? It maybe something else but I don't think it was linked to the water.

Terry

No, I haven´t used more, hopefully today I´d make a test at my flying club, (usually flies there)

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Well today I went to my flying club where I usually fly and the image was perfect and clear as always. Don´t know really what could happen yesterday, but I´ll come back and try diferent things.

Edited by Wavess

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I could be wrong, but isn't the 2.4 Ghz spectrum the same used by microwaves for heating water? With a lot of water droplets in the air, couldn't the power being emitted by the Tx be absorbed by the water droplets, resulting in a decreased signal strength? It would be interesting to see what the reception would be like on a non rainy day.

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Exact. I've experienced factors of 2-3 in range between dry and humid weather.

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remember why microwave owens use 2.4GHz ?!?!

since all food it is supposed to heat up consist mostly of water,

and since the particle resonanse in water is 2.4Ghz, the heat-up

will be much more effective.

Water particles in air will suckup 2.4Ghz,

in a cloud or in really humid conditions if you are using most of your range margin,

you will see the difference.

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Looks like another video feed to me. The background signal looks to have sync.

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