Underwater video signal

[Francisco Xavier]

Hi,


I just finish assembling my BW underwater video. I used for wiring 100 meters two conductors common wire, one of them is 12 V positive and other the back 1 MHz video signal. The ground


(-12V)is made by the sea water using underwater stainless steel screw on the boat and outside the housing.


I have degraded picture.


Can I improve the picture quality using inside the housing a video amplifier or I must ajust the impedance/capacitance of the cable.


Do you thing I can get good picture using normal wiring?


Any help are welcome.


Thanks.


Francisco Xavier Sousa

[Carl]

Re: Underwater video signal

1MHz over 100m might require a better cable. Also, what is the supply voltage drop over 100m of seawater for your rig? You might have severely degraded the supply voltage to the camera.


- Carl

[Francisco Xavier]

Re: Underwater video signal

Thanks Carl for your advice.


After spending hours around (until 6:30 Am Saturday) I could incrase the picture quality. The voltage (12 V) d'not decrase, the BW camera needs just few milamps supply. and the 100 m.wire just have 2 Homs. After changing a lot, I send by the cable the video signal and negative supply, the positive supply by the sea water. More I have to ajust the signal level just conecting a 10 KHoms potentiometer beteewn signal and negative (about 128 Homs) and the picture quality was great.


I never expect to have this picture quality with 100 meters with a reel of common wire.


So I think to use the same cable to work with magnetometer and after the vídeo.


Best regards Carl,


Thanks,


Francisco Xavier Sousa