Screened or unscreened Cat5e for CCTV installations ?

[csorts 0]

Hi folks

 

I'm planning to do a CCTV installation with Cat5 for the first time as I have always used coax.

 

Can anyone recommend whether to use screened or unscreened Cat5 & also should it be Cat5 e enhanced ?

 

Thanks

 

csorts

[the toss 0]

Screened is always going to be better , but it's not neccessary and a fair bit more expensive. Cat6 would be better simply for thr fact that it is a thicker guage. Why have you opted to use twisted pair ?

Keep in mind that twisted pair was never designed for composite video signals. It has been adapted to that purpose by the use of matching transformers (baluns) which will cause an insertion loss of 1 or 2 dB per balun.

The ONLY advantage I can see in using cat5/6 is the fact that one cable can be utilised for multiple cameras if they are mounted in close proximity.

[Kawboy12R 0]

You don't like the ease of migration to network cameras in the future when running UTP for analogs? It isn't necessarily the best for analog, but in many cases it's a very good alternative to coax that makes future upgrading quite simple.

[balunman 0]

Cat5e/6 unshielded twisted pair is recommended when used with CCTV baluns unless it is an electrically noisy environment such as an industrial plant in which case shielded twisted (STP) is recommended for additional noise immunity. If STP is used, the shield must be grounded at least on one end, if not both.

 

In case of ground loop, a ground loop isolation balun may be installed on one end to break the ground loop.

 

example: http://muxlab.com/product?category=cctv&product=cctv-pass-thrugli-balun&pid=37

[the toss 0]

You cannot get a ground loop by earthing the shield of STP cable. Ground loops are created when the earth and signal share a common path. ie unbalanced as for coax .