Mini cam connections query.

[collectors]

Hi, i am hoping someone might know this. I am looking to put some cameras around the railway layout & was looking at some of the tiny cctv cameras you can get nowadays.
Now they come with a 3 wire lead of red + Black - & yellow Video. Now the incoming 2 leads have 12v plug for the + & - & a coax. So the yellow will connect to the coax centre core, but the coax also has brought a screeded outer cable to the mini cam. What, if anything should be done with this? Thanks

[Rog (RJ)]

The screen should probably connect to the black.

[collectors]

That's what i was thinking as its potentially an earth but not via a transformer. When i get the items i will try without, then with. Maybe the chassis earth at the DVR is enough.
Must admit i am sometimes dubious when a DVR comes with a two-wire connection, then they put an earth lug/screw on the DVR body for the earth that the coax screen would be attached to.

[Rog (RJ)]

When you say DVD, what are you referring to?

[collectors]

When you say DVD, what are you referring to?

Sorry, a senior moment with my abbreviations. CCTV DVR. I have corrected it.

[Rog (RJ)]

Makes sense now, thanks.

[Brian]

So long as the co-axial screening is connected at one end it really shouldn't / doesn't matter if the other end is not connected. But do ensure the screening can not touch other cores or live parts.

[collectors]

So long as the co-axial screening is connected at one end it really shouldn't / doesn't matter if the other end is not connected. But do ensure the screening can not touch other cores or live parts.

Thanks,