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ahab

I FINALLY GOT WHAT IWANT

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well guys it took me a while and a lot of advice from you but I finally got there

Heres how I can get superb aerial video with zero dropouts recorded in the aircraft

The Camera:

CCD 480TVL 12V waterproof bullet camera and microphone all loomed up marketed as a Helmet Cam £165 from RF concepts

The recorder:

Mustek PVR A-1 190g with 512meg sd card from pixmania £123.90

Tx:

Uk legal 10mw 2.4 Ghz 4 channel with fitted rubber duck Maplins UK £34.99

For power:

2100MaH nMih 4.8v pack 4.8v to 12v booster chip Farnell UK £24

Rx

2.4 GHz Rx I had laying about with GP patch

To view

Eye trex goggles Ebay £77

As my planes are all pretty big it was decided to use the spare room to the max

What I have been trying to do is transmit good video to the ground - then record it

so I have been recording what I saw

the Mustek A1 is small enough to fit in the plane and is wired directly to the camera

the A1 is set to record before the flight and stopped at the end the result perfect video with no range or multipath interference problems

the camera is Y leaded into the Tx and the signal is tranmitted to the ground and I use the eye trex to view the action along with multipath interference

What I am now doing is recording great, clean video in the air and viewing what the camera sees, on the ground

I can then play back the video and sound on the A1 then transfer it to my Pc then burn to cd and view on TV MAGIC

The bits of test movie are huge files but I will post on here when I can

Thanks again Folks

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What resolution does it record video in?

What I do is run a Nikon 3700 digital through my wireless system. It records 640X480 and also transmitts the video back to my tv set.

That negates the need for a CCD camera. It's built into the Nikon and the camera also records the flights.

All I need external power for is the transmitter as the camera has it's own li ion battery.

Edited by randall1959

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Not quite sure of the record res but I am reliably informed that it is 640 x 480 in SP mode and less in LP mode

your setup seems ideal

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Soory got that wrong KILRAH tells me in an earlier post that the PVR A1 records in 320 x 240 but it still looks ok when I burn it to dvd then play it on my 32" plasma

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Yep that's right. But what I'm amazed of is that it works by simply using a Y-wire to split the video between the PVR and the TX. It should be problematic because of the impedance being incorrect (sync lost or dark picture). I have never managed to do such a thing without a video buffer... :unsure:

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I'm not quite why it works either but it does. now I can view what the camera sees and when there's dropout I don't care because I know I'm not recording the rubbish.

With the raw footage from the A1 , What would you consider to be the best format (codec?) to save it as after Movie Maker? I am writing to DVD so size is not going to be a problem, I won't need compression

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I think I know why the Y lead works Just by a complete fluke my TX video in impedence is 75ohms so is the camera's lucky eh

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It depends what you want to do, if you want to play the video on a home DVD player (not a computer), you will need a DVD authoring program that will encode the video in the DVD MPEG-2 standard, with all the needed directory structure. Movie maker doesn't support this. In that case either you do the editing with that program, or you do it in Movie Maker and export as DV before opening the video again in the other program. This will minimize the quality losses inbetween.

If you plan to use a computer to play the video, you can use WMV9 or DivX codecs at relatively high bitrate (2Mbps). That's what I use for archiving. In that case keep the output resolution at 320x240, enlarging will reduce quality.

For your video TX it's normal, all common video equipment should have a 75 Ohm impedance. But the problem is here:

The camera output has a 75 Ohm impedance. When connected to another device, as its input impedance is also 75 Ohm they are matched.

When connected to 2 devices, the camera sees 2x 75 Ohm in parallel, that is 37.5 Ohm. Thus the signal on the devices will be lower (a bit like a voltage divider to simplify. There are also other issues as high frequency signals will be reflected when the line impedance is not continuous.)

Maybe some inputs have an AGC which makes them more tolerant... but that would be surprising at least for a video TX.

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The dvd authoring program I am using is Arcsofts showbiz 2 (came bundled with the DVDwriter) I am editing first in movie maker then exporting to showbiz 2

not sure I understand about impedence but it seems that my setup works ok

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