Home Installation - Cat 5 (or 6) with Balun vs coax/power

[niceguymr 0]

Hi everyone. I'm so glad I have found this forum.

 

I just ordered a Q-See system from Costco. Yep, I already understand that this is low grade stuff, but I'm ok with that. It was $499 for a 16ch with 8 Cameras. The cameras it comes with are the QM6006B which I have read here come with what is considered to be cheap (poor quality) cables. Then I read people recommending to just use Cat 5 cables and Baluns. So I had no idea what a balun was until I started searching and reading some more and now I think I understand, but I have several questions:

 

First - Is there any performance disadvantage of using Cat 5 (or 6) cables with a Balun instead of using the coax/power cable that's included with my system? My longest cable run with be maybe only 50 feet and the shortest will be 20 feet.

 

Next - I see that Amazon has pairs of Baluns (I assume they always need to be bought in pairs for my application, right?) for $12.99 (http://www.amazon.com/LTS-LTA1010-Passive-Video-Connectors/dp/B001HBP9ZC/ref=pd_cp_p_0) and Monoprice has something similar for $8.75 (http://www.monoprice.com/products/product.asp?c_id=110&cp_id=11011&cs_id=1101101&p_id=6878&seq=1&format=2). Are THESE what I should be looking for? Are there any better deals on this type of stuff?

 

Next - Will a Cat 5 Balun work with Cat 6 cable? The reason I ask is I already have several hundred feet of Cat 6 and I would prefer to use it if I can instead of orderiing a roll of Cat 5.

 

Last - What esle if anything do I need to know about using Cat 5/6 cable with baluns instead of the supplied coax/power cables? Is this simply a no brainer and as simple as it seems?

[Soundy 1]

Is there any performance disadvantage of using Cat 5 (or 6) cables with a Balun instead of using the coax/power cable that's included with my system? My longest cable run with be maybe only 50 feet and the shortest will be 20 feet.

Only probably downside, if you're using a central power supply for all the cameras, is ground loops. This is an expected side-effect of using baluns with cheap cameras that use a common video and power ground.

 

Will a Cat 5 Balun work with Cat 6 cable? The reason I ask is I already have several hundred feet of Cat 6 and I would prefer to use it if I can instead of orderiing a roll of Cat 5.

Baluns will work with just about any pair of wire: Cat5, Cat6, Cat3, phone wire, station wire, speaker wire... extension-cord wire, in a pinch... twisted-pair wire adds an extra degree of interference rejection, but that shouldn't be a problem with the short runs you're dealing with.

 

Cat5 and Cat6 DO require different RJ45 connectors, as Cat6 is a heavier-gauge wire than Cat5. Make sure you get the right ones.

 

 

What esle if anything do I need to know about using Cat 5/6 cable with baluns instead of the supplied coax/power cables? Is this simply a no brainer and as simple as it seems?

Nothing else, really... if the cameras include individual wall-wart power adapters, I'd stick to those, to avoid the ground-loop problem.

[niceguymr 0]

Is there any performance disadvantage of using Cat 5 (or 6) cables with a Balun instead of using the coax/power cable that's included with my system? My longest cable run with be maybe only 50 feet and the shortest will be 20 feet.

Only probably downside, if you're using a central power supply for all the cameras, is ground loops. This is an expected side-effect of using baluns with cheap cameras that use a common video and power ground.

 

Let's suppose I'm using a central power supply (because I ordered one already ) What is the solution to ground loops? Actually, what exactly is a ground loop?

 

Will a Cat 5 Balun work with Cat 6 cable? The reason I ask is I already have several hundred feet of Cat 6 and I would prefer to use it if I can instead of orderiing a roll of Cat 5.

Baluns will work with just about any pair of wire: Cat5, Cat6, Cat3, phone wire, station wire, speaker wire... extension-cord wire, in a pinch... twisted-pair wire adds an extra degree of interference rejection, but that shouldn't be a problem with the short runs you're dealing with.

 

Cat5 and Cat6 DO require different RJ45 connectors, as Cat6 is a heavier-gauge wire than Cat5. Make sure you get the right ones.

 

 

What esle if anything do I need to know about using Cat 5/6 cable with baluns instead of the supplied coax/power cables? Is this simply a no brainer and as simple as it seems?

Nothing else, really... if the cameras include individual wall-wart power adapters, I'd stick to those, to avoid the ground-loop problem.

 

OK, So I suppose I should have waited to post questions till I actually received my order. It should arrive this week and I'll know about the adapters, but.. Even if they do have individual adapters, I really don't think I want to have 8 AC outlets tied up by a bunch of cameras. Am I misunderstanding something here? Or do I just get one of those extension cords with a multi outlet strip on the end and connect all the camera adapters to one of those? Sorry for not underderstanding and thank you for your response.

[Soundy 1]

Let's suppose I'm using a central power supply (because I ordered one already ) What is the solution to ground loops? Actually, what exactly is a ground loop?

A ground loop occurs when a signal has two different paths to ground of differing potentials - which most often means, two very different resistances. It causes the line to behave like an antenna, picking up all manner of interference and electrical noise.

 

For example, a camera whose case is connected to its signal ground, mounted to a metal building, will have its direct signal path to the DVR ground (which is usually connected internally to an earth ground); it will also see a path via the building, into the earth, back to the DVR via the earth ground on its power supply... but with all that extra metal and the earth itself in the path, it will have a different resistance than the direct path.

 

In this case, cheap cameras' electronics will share a ground point for the power and signal. A balun is essentially a transformer with its windings in-line with the video and ground leads. Since transformer windings have significant DC resistance, that means there's resistance in the signal ground path. Now the signal will also find a ground path via the power ground connection, back to the power supply, then via another camera's power ground, and finally back to the DVR via that camera's video ground... which is going through another balun, thus adding resistance to that path... and boom, you have a ground loop.

 

Typically as you add more cameras, the problem becomes worse, as every one of them creates yet another path to ground. With 8 cameras, that means each camera will have eight separate signal ground paths, each of different potential.

 

The fix is to break the multiple paths somehow. Using separate wall warts means the cameras don't have a path via the other cameras' power grounds. Using cameras with built-in regulators (particularly dual-voltage types) means they have separate power and signal grounds, so the problem doesn't occur. Or your can get ground-loop isolators, but to me that's a "hack workaround", just throwing money at a symptom rather than spending it to avoid the problem in the first place.

 

All this means is that the wiring is much more likely to pick up even the slightest interference. If you're in an environment with very low electrical noise, the problem may be minimal and possibly not even noticeable.

 

OK, So I suppose I should have waited to post questions till I actually received my order. It should arrive this week and I'll know about the adapters, but.. Even if they do have individual adapters, I really don't think I want to have 8 AC outlets tied up by a bunch of cameras. Am I misunderstanding something here? Or do I just get one of those extension cords with a multi outlet strip on the end and connect all the camera adapters to one of those? Sorry for not underderstanding and thank you for your response.

 

Just need the appropriate power bars There are plenty out there that have multiple wide-spaced outlets for transformers.

[niceguymr 0]

In this case, cheap cameras' electronics will share a ground point for the power and signal.

 

How do I know for sure if the Q-See cameras in my set fall into this category (not that I have any doubts that they are cheap cameras). How do you know with any camera if they are going to have this problem?

 

Can you give me an example of the least expensive camera that would have similar specs and not share this ground looping problem? I'm curious what's the threshold I need to cross (spendwise) to get into cameras that don't have a grounding loop problem.

 

And Thank You for a wonderful and thorough explanation. I'm learning a lot here.

[Soundy 1]

How do I know for sure if the Q-See cameras in my set fall into this category (not that I have any doubts that they are cheap cameras). How do you know with any camera if they are going to have this problem?

Put it this way: the majority of 12VDC-only cameras will be a common-ground design, because it's just cheaper and easier. You can test it pretty readily with a multimeter or some other kind of continuity tester - just see if there's continuity between the power and video grounds.

 

Can you give me an example of the least expensive camera that would have similar specs and not share this ground looping problem? I'm curious what's the threshold I need to cross (spendwise) to get into cameras that don't have a grounding loop problem.

Anything that lists as dual-voltage (12VDC/24VAC) should be fine, because it will have an internal rectifier and regulator that separates the two grounds. Hard to say what else would be equivalent specs-wise, let alone in the price range... NexTag shows an Amazon.com ad that claims this cameras "lists for $150" but then is marked down to $60, along with other listings of anywhere from $60 to $85... a Buy.com listing claims the retail price for this camera is $200(!!!) but they'll sell it to you for $80 with free shipping. So should I be comparing to a $60 camera or a $200 camera?

 

Put it this way: this camera goes for around $165, and blows away the specs on the Q-See in every regard, including being dual-voltage so they have no problems with baluns: http://www.cnbusa.com/en/html/product/product.php?seqx_prod=1073

 

It would be impossible to give a specific "cost threshold" because there are so many other things that affect cost... including, it would appear, whatever numbers a seller is willing to throw around to make it look like you're getting a good deal.

[the toss 0]

Let's suppose I'm using a central power supply (because I ordered one already ) What is the solution to ground loops? Actually, what exactly is a ground loop?

A ground loop occurs when a signal has two different paths to ground of differing potentials - which most often means, two very different resistances. It causes the line to behave like an antenna, picking up all manner of interference and electrical noise.

 

.

 

That can be an issue in audio installations where a common earth loop fix is to unearth one end of a low power transmission medium (eg a mic cable) but not usually the cause of interference in camera systems. What the problem really is as you say is the different earth potentials. Any differing potential will cause a current. Since the earth is the reference for the signal any foreign earth current will superimpose on the signal. This is most common on unbalanced configureations. On balanced systems the earth is not the signal reference & with the use of differential input circuitry most induced noise is eliminated via common mode rejection techniques