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We have mounted cameras on R/C cars. They are racing on a indoor track. The longest range between the transmitter and receiver is about 30 meters.

We have three different camera systems. One XCam2 (not modified), one Hong Kong variant and one Sony CCD with 600 feet transmitter/receiver (I don't have the exact facts about these at home).

Our problem is the same on every camera. When not moving the picture is superb but when the car moves we got picture interference. I have read the FAQ and it sounds like multipath interference.

Is there any way to avoid or at least minimize the interference? Will for example "stronger" transmitter/receiver make things better?

Are there other solutions transmitting wireless video indoors?

We really have to make this work and we are very glad for suggestions.

Thanks,

Jocke

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When not moving the picture is superb but when the car moves we got picture interference.

Can you post a link to a video that shows the problem?

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Yes I can post a videosample but not today. Earliest tomorrow because the cameras are at the track and we dont have Internet there yet.

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Hi Jocke.

This ay seem an obvious question ,Where are you taking the power supply from for the Tx.?

Personaly I have found the best way is a dedicated supply for the video system.

Johnstorm

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First a answer to the power supply question, we use a 9V battery but are thinking of other alternatives, we just haven't figured out which is the best solution yet.

Second, here is a link to the videosamples, the files are rather big ~20MB and ~45MB.

http://user.tninet.se/~knb645t/testdrive.htm

We are using an AV-AT-Air 100mW transmitter/reciever system with the sony camera.

- As you can see on the samples we turn on the car transmitter after a few seconds. Thats when the diagonal interference starts.

Question 1: Is it possible to reduce the transmitter interference so it wont affect the video so much?

- The white horisontal flashes that occurs constantly is the interference that confuse us. We have no idea about what's causing them.

Question 2: What could cause this and what can we do about it, any ideas?

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With MediaPlayer 7, the videos are just solid blue screens with no sound. Hopefully someone else will be able to view them and offer advice.

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The diag lines are not due to multipath interference. It is EMI/RFI, either from the ESC or motor; Probably from both.

I think you will see the interference whether the model is moving or not. Instead, it is probably present only when you run the motor. If that is true, then you need to revamp your motor's noise suppression. How many suppression caps are installed and how are they wired? If improvements there do not help, then try a different ESC.

Keep the Camera and Tx as far away from the model's motor/ESC/wiring as possible. For sure, do not share the camera/Tx power with the model's battery. That will only make things more difficult to solve.

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Thank you for the answer! I now think that we can get rid of the diagonal interference.

The horizontal flashes are our biggest headache. They even occur when we walk around with the camera. There are no microwave oven or wireless phones at the place.

Regards

Jocke

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The horizontal flashes are our biggest headache.

The bright intermittent white flashes are multipath related. Microwave signals are prone to that sort of problem; Your indoor arena is a difficult environment.

I do not have any practical advice to offer. Maybe someone else can offer a solution. The best I can say is that if you have a ham license, then you can try a UHF (i.e., 434Mhz) video Tx to see if it works any better for you. The various ATV ham suppliers sell these.

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