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Hi all

When I connect my Canon Pro 1 to a video transmitter the on screen info causes a horizontal distortion bar accross the whole screen, ant ideas how to cure this ?

Thanks, Terry

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The video level of your Canon is a tiny bit too high for your transmitter. If you can open your tx, look for a small potentiometer inside. Be careful, there might be multiple ones.

One of them should adjust the video level. You can back it down a bit to resolve the horizontal distortion.

Regards,

Bill

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Thanks for your reply Bill but I have already done that. If I turn the pot down the picture will switch to black and white before the distortion goes. When it is black and white there is no problem and the picture is perfect.

Terry

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How many mW's of RF is your video Tx?

I suspect it is video RF getting into the camera, then being coupled into its video signal. Does the interference's intensity reduce a bit when you remove the antenna from the video Tx? {You'll have to place the video Rx next to the Tx during this test.} Keep the camera away from the Video Tx and be careful how you route the various cables.

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I tried your test and it makes no difference probably because Im only using 10mW. Is there a simple way I could reduce the level of white in the signal and not effect the other colours ? Maybe some type of filter ?

Terry

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Can you post a photo of the problem?

Do you have an oscope? If you do, what is the pk-pk voltage, from the bottom the sync, to the top of the highest white level? This must be measured at the camera connection while connected to the Video Tx. Repeat the measurement at the output of the Video Rx, while connected to your monitor. What do you see there?

Is there a simple way I could reduce the level of white in the signal and not effect the other colours ? Maybe some type of filter ?

It would not be simple to do that. Besides, there is a good chance the problem is on the Rx side. It is beginning to sound like a DC restore problem.

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I will need to get my scope back and test it, this my take a week or two though. If you think the problem may be on the rx side is it worth me trying another rx ?

Terry

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If you think the problem may be on the rx side is it worth me trying another rx ?

Just use the o-scope. It will help identify if the problem is related to over-driven video levels. If the video is in spec, then the problem will probably be tough to solve.

Here is another test. Assuming the digital camera video looks fine when you record it directly to a VCR, what happens when you play the recorded video through the Video Tx? Is the band present?

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I just tried another rx and the picture was fine so I took off the lid of the offending rx and found a tiny pot. I only just touched the pot and the picture was perfect. It seems this tiny pot is a bit too easy to move by vibration so I have put a dab of glue on it. Many thanks for your help, I dont know how long I would of been messing with the tx before I looked at the rx !

Terry

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Im not sure of the make of the rx but it looks the same as the $65 one from Black Widow. The tx is from Maplin Electronics in the UK.

Terry

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