PAL TV composite signal from camera HELP PLZ...

[TekUT]

tv composite signal

Dear all,
I'm developing a pipe inspection system and I'm in a hurry as usual now it's all ok but I'm losting the color information from the cable end or better say is not stable and I've sometimes the color that is missed and image is in gray scale.
I've attached a scope waveform taken from the cable start and the cable end (100 meters length) and also, to be honest the cable isn't a really video cable because due to size I've need a cable with overall outline diameter less or equal to 5.5 mm able to carry video and also power to supply the pinhole camera that I've used. Image quality is good, sharp, but sometime colour was missed.
At the camera output, before going into the cable I've a 75 Ohm resistor same at the cable end before going into the receiver.
If someone could take a look at the waveform and gimme some suggest I'll appreciate it.
Thanks in advance
Powermos

 

[IanP]

You need to add video amplifier/equalizer, similar to this:
https://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1154,C1009,C1044,P1420,D4289
It compensates for cable loses, especially for loses in sharpness and colour (higher part of video signal spectrum) ..
Rgds,
IanP

 

[TekUT]

Dear IanP,
thanks for the link, from datasheet I've to add this circuit on the receiving side of the cable (at the cable end). I'll try with this device and report back results.

Regards
Powermos

 

[TekUT]

Just to inform, I've solved by using a simple cascode amplifier from this link:

**broken link removed**

Bye
Powermos