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robyr1

on board video from a Cessna! suggest?

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On 28th June there is an important event here in south Italy. An air show with a lot of important teams. I would like to fit an on board camera with a video TX. Here are what i would like to do:

Airplane equipment:

- 2 bullet cameras Sony 580 TV lines connected to a SS1000 chasecam video quad (for a picture in picture)

- The video out (with PIP) connected to the video IN of my 2W 2,4gHz TX

- Audio out from the interphone connected to the audio IN of the TX

- The TX antenna will be a common "stilo" 3db, but i can fit a patch antenna 11db instead: what's your best suggest?

Rx equipment:

- n.1 directional 15db antenna

- n.1 patch 15db omni antenna

- n.1 Oracle diversity

- n.2 receivers (same boundle with the TX!)

- n.1 LCD monitor to see

- n.1 video out is for the TV for live

What do you think? the maximum distance is 1km, the minimum is 500mt. the place is in front of the sea.

May i have to move up (around 10mt) the double antennas?

Or is there a better way to send live video via internet? we have a lot of space for our equipment inside the airplane!!! If yes, what's your suggest?

this equipment works well with RC planes, but i never tested before on a real airplane!! :D

Edited by robyr1

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2W, 1km?!

You'd get away fine with 3dB antennas everywhere. What I'd do is use the 3dB on the plane, another one on the first receiver and a relatively low gain patch (the good old 8dBi) on the second RX, more for interference rejection than range. Receiver location won't matter much as long as the view on the plane is clear.

Of course you'll need to find a way to put the transmitter antenna outside of the plane for best results.

I guess you don't have your broadcast transmitter yet then?

Edited by Kilrah

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2W, 1km?!

You'd get away fine with 3dB antennas everywhere. What I'd do is use the 3dB on the plane, another one on the first receiver and a relatively low gain patch (the good old 8dBi) on the second RX, more for interference rejection than range. Receiver location won't matter much as long as the view on the plane is clear.

Of course you'll need to find a way to put the transmitter antenna outside of the plane for best results.

I guess you don't have your broadcast transmitter yet then?

Thanks for your answer!

I contacted a lot of different suppliers of broadcast Tx's, but nobody assure for a "fast moving object" use. As i told you before, i would like to use that tX's on bikes, cars, and now we are the official suppliers of the minicams for the world powerboats championship offshore: www.class-1.com

What is the software to use to measure the RF level to the TX and RX?? Because i have only the LCD monitor to see the video!

Anyway, sorry for my stupid question: but more db is not better than less db??

Is there a way also to send a live video (good quality) from a boat or airplane with internet???

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Well, some must be able to handle fast moving objects, see formula 1...

And remember that a fast moving object isn't always moving fast with regard to the receiver as soon as it isn't right next to it... if you put your receiver just over the straight line of a formula 1 track you'll have the car approaching at 300km/h, pass the RX, then go away at 300km/h... but if you put the receiver 500m outside of the track, the car will go maybe 10x slower with regards to it in what counts for Doppler effects.

It's not software you need to measure RF level, but expensive RF level meters. But those can be avoided if planning correctly :)

More dB is not always better, it all depends what you want. Of course you can use a 30dBi antenna to receive from your plane, you for sure won't lack RX level with that, but you'll have to precisely aim at the plane all the time (within 3 degrees), which is pretty much impossible to do. So, if you have enough power anyway, why complicate and use an antenna requiring aiming when you can do without?

A 8dBi antenna has a pretty wide coverage, and doesn't have steep loss when you get out of it, so you'll be able to just put it there and leave it alone while you enjoy the show. I fly 1km away with 10mW and 8dBi, so with your 2W you should have much more margin than needed...

The 15dBi has a narrower coverage, and loss is also higher outside of it, so you might have to aim.

A 15dB omni antenna is useless for flying objects, as when mounted vertical its optimal sensitivity zone is not more than 3-4° above horizon. Just have a look at the specsheets and sensitivity diagrams of your antennas...

Frankly, if you're starting to commit for big events like this I'd suggest you team with or hire a technician who will understand these matters and preferably has some experience in the field.

For a live internet broadcast you need to capture/encode your video on a computer, then upload that to a streaming server which relays to the clients from a high bandwidth line.

Edited by Kilrah

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thanks a lot!!

so i'll test it with a simple antenna, should be more simple!!

I think wich all is much more easy to do it, but i'll test it on thuesday afternoon.

Thanks again!

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Kilrah!

here are a pic of my equipment.

this is the TX: 2,4ghz 2W, there are 2 antennas available, the white one is much more longer, is better than the black one?

tx2w.jpg

and here are the RX antennas:

DSCN4880.JPG

DSCN4881.JPG

DSCN4882.JPG

what's the best cominations??

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I can't tell you anything without the spec sheets of the antennas... exterior casing usually means nothing. Often those "long" whip antennas have nothing more than the short ones inside, and the longer shape is purely cosmetic.

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Looks like you got it working fine. The diversity antenna setup seems to be doing its job.

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