RG59 Siamese cable quality

[mrg99 0]

I have a chance to buy some spools of RG59 Siamese cable at a good price.

The center conductor is 20AWG solid copper, the braid is 95% and the power cables are 18AWG stranded 100% copper.

The braid is CCA.

The cable I normally use is 100% copper braid (all other specs being equal).

How concerned should I be about a CCA braid as far a quality over 200' runs ?? Thanks.

[the toss 0]

Depends on how much of a gambler you are. Braids aint braids. They are designed for the shielding of the signal frequency being carried. CCTV baseband frequencies run to about 25Mhz. Could be a big PITA to pull it out & re-run the good stuff

[jeromephone 6]

Are you thinking of using this in your house or selling it to a customer? There is probably a reason you are getting a good price they cannot sell this because of code or installers do not want to take a chance on it.

[IdahoMan 0]

I'm glad this topic came up.

 

I need to setup some CCTV within a foot of some hyper-sensitive radio equipment, so I can't have any interference from the CCTV equipment. That's why I'm looking for some good siameses rg59/rgr6, instead of cat6 for instance.

[mrg99 0]

Are you thinking of using this in your house or selling it to a customer? There is probably a reason you are getting a good price they cannot sell this because of code or installers do not want to take a chance on it.

 

I'd be using it in my own home.

Isn't RG6 a pure aluminum braid? Is a pure copper braid that much more effective at shielding the signal?

[the toss 0]

mrg99 - it sure is.

 

@ IdahoMan - I have NEVER been able to measure radiated signal from a CCTV baseband transmission line. The shielding is primarily to prevent ingress of radiation to the coax. If you are that worried about interference then DONT use RG6 use RG59 with 0.9mm centre & 95% copper braid

[IdahoMan 0]

 

@ IdahoMan - I have NEVER been able to measure radiated signal from a CCTV baseband transmission line. The shielding is primarily to prevent ingress of radiation to the coax. If you are that worried about interference then DONT use RG6 use RG59 with 0.9mm centre & 95% copper braid

 

Interference to the CCTV system is a concern too, that's why I figured coax would be better.

 

Thanks for the info. And RG6 can work just as well or better than RG59 as long as the requirements (materials(BC), braid coverage(95%), and impedance(75ohms)) are met, yes? They make R6 that has the same specs as RG59 but with, IIRC, larger gauge center wire.

 

Toss, How do measure radio interference? Spectrum analyzer?

[mrg99 0]

mrg99 - it sure is.

 

Are you referring to the fact that RG6 has an aluminum braid or that a 100% copper braid would have a much better shielding effect than CCA???

[the toss 0]

 

@ IdahoMan - I have NEVER been able to measure radiated signal from a CCTV baseband transmission line. The shielding is primarily to prevent ingress of radiation to the coax. If you are that worried about interference then DONT use RG6 use RG59 with 0.9mm centre & 95% copper braid

 

Interference to the CCTV system is a concern too, that's why I figured coax would be better.

 

Thanks for the info. And RG6 can work just as well or better than RG59 as long as the requirements (materials(BC), braid coverage(95%), and impedance(75ohms)) are met, yes? They make R6 that has the same specs as RG59 but with, IIRC, larger gauge center wire.Toss, How do measure radio interference? Spectrum analyzer?

 

 

I have had this discussion many times and have heard many people say this about the specs. Since most people have little concept of coax cable design/construction I usually put this question to them. IF this RG6 they make does in fact have the same characteristics as RG59 (but with larger centre) then why isn't it just called "heavy duty RG59". Why would a manufacturer confuse things when they already make a RG6 which is spec'd for digital TV. When you say this RG6 has the same specs as RG59 what specs are you referring to. Are you looking at things like transconductance, slew rate & velocity factor or just limiting yourself to the "salesmans" specs of braid coverage , dc impedance & centre conductor. There is SOOoo much more to coax cable design. It is a bit like thinking an engine management computer from a BMW is going to work in a Toyota. It wont - the parameters are completely different.

 

Measuring RF interference ? Well in a previous life I had access to Refractive Interference Spectrometers & tuned cavity resonators. In many cases it is not a matter of measuring unwanted RF power (interference) as measuring the EFFECT of that interference on a know test signal in a transmission line.

 

Now days alas all I have is a humble spec analyser.

[IdahoMan 0]

To bad there isn't a website that shows detailed lab tests of certain cable types with documented results.

 

BTW,

 

There is RG59 with an extra layer of foil too. What to you think:

http://www.cctvopticallens.com/product/3-7mm-2Megapixel-F2-5-M12-Mount-Sharp-Cone-Pinhole-Lens.html

 

I can't sell my kidney to buy Belden, sorry.

 

In many cases it is not a matter of measuring unwanted RF power (interference) as measuring the EFFECT of that interference on a know test signal in a transmission line.

 

True. However, getting more a little more tight and in-depth: There are also security reasons. Anything that gives off radiation (heat, light, radio, etc.) can be detected. The objective is to shield the systems from detection. There are materials, including paints made for shielding.

[IdahoMan 0]

To bad there isn't a website that shows detailed lab tests of certain cable types with documented results.

 

BTW,

 

There is RG59 with an extra layer of foil too. What to you think:

http://www.cctvopticallens.com/product/3-7mm-2Megapixel-F2-5-M12-Mount-Sharp-Cone-Pinhole-Lens.html

 

 

 

Nm. CCA.

[ilk 0]

I'm glad this topic came up.

 

I need to setup some CCTV within a foot of some hyper-sensitive radio equipment, so I can't have any interference from the CCTV equipment. That's why I'm looking for some good siameses rg59/rgr6, instead of cat6 for instance.

 

Why don't you use fibre then?

 

Guaranteed interference free (both ways).

 

Ilkie

[IdahoMan 0]

I'm glad this topic came up.

 

I need to setup some CCTV within a foot of some hyper-sensitive radio equipment, so I can't have any interference from the CCTV equipment. That's why I'm looking for some good siameses rg59/rgr6, instead of cat6 for instance.

 

Why don't you use fibre then?

 

Guaranteed interference free (both ways).

 

Ilkie

 

Have been thinking about that too, but haven't researched it. A a fiber-optic cable between the camera aperture and the lens. No metal. Got any links?

 

But I still need to find some RG59 Siamese.

[jeromephone 6]

another curve cat 6 shielded? would that work ? fiber would solve the interference problem and is not too expensive per foot but you would need to terminate it and use some kind of media converter which would jack up the costs. What % of the job are cable costs?

[ilk 0]

I'm glad this topic came up.

 

I need to setup some CCTV within a foot of some hyper-sensitive radio equipment, so I can't have any interference from the CCTV equipment. That's why I'm looking for some good siameses rg59/rgr6, instead of cat6 for instance.

 

Why don't you use fibre then?

 

Guaranteed interference free (both ways).

 

Ilkie

 

Have been thinking about that too, but haven't researched it. A a fiber-optic cable between the camera aperture and the lens. No metal. Got any links?

 

But I still need to find some RG59 Siamese.

 

The fibre optic cable provides the IP connectivity from the camera to the network switch.

 

Can buy pre-made terminated fibre cables, the use of which would depend on the cable pull.

 

You would need to use media convertors (for example google comnet, there are other manufacturers) that offer 100BaseT or Gigabit.

 

You many cameras can use the same circuit so you can use the fibre circuit as back bone home run.

 

Ilkie