2 questions - Mixing RG6 & RG59 - Cat5 kinks

[boybloo 0]

On a 200 ft run of Cat5 I've connected a balun. I then have a 5ft run of RG6 from my baluns to my DVR.

 

On the camera end there will be a short piece of coax between the balun and the camera.

 

I ran out of RG6 twist on BNC's so I was tempted to use RG59 on the camera side. I decided to wait & get the RG6 BNC's. Would there have been an issue if I had used the RG59?

 

second question, I have an existing Cat5 line that was twisted around a nail. I was wondering if I straighten out the kink will the wire be ok to use for video. I'm going to use the lines for power but I wondered if I did use the lines for video what would be the result.

[CollinR 0]

The RG59 and RG59 BNCs is actually the correct cable for the job. So if there were an issue it would probably come from so many interconnects and then the RG6.

[rory 0]

Yep like Colin said, should be RG59, or if it is RG6 should at least be Copper inner and outer. The regular Cable TV coax, which has aluminum braid, can typically cause problems.

 

Otherwise, you should have been able to fit an RG59 BNC Connector on the RG6 cable, as I have done in the past when I had no choice - its a tight fit though and will not normally be on tight.

[boybloo 0]

Man,

That's some really bad news. I paid 2.50 ea for 60 RG6 connectors and I’ve already used half; but at the same time I want to do everything right. Do I need to change the RG6 that I’ve already installed?

 

The RG6 I’m using does not have a copper braid. I have 8 Cat5 runs of about 200ft and on three of those runs I need to add coax runs (balun in between) of 80, 40 and 20 feet.

 

Although the Cat5 does reach the cameras, tight turns, stapled wire, and kinks worry me, so I’m going to cut those back to the point where it looks good. On the other 5 runs the Cat5 looks ok so I need only a short piece of coax to go between the balun and the camera. How short should that piece be?

 

I used RG6 because I thought bigger is better. What problems come with using the RG6?

[survtech 0]

You can continue to use RG-6. RG-6 and RG-59 are interchangeable for short runs (less than a few hundred feet) in most applications, as long as the construction is copper/copper. The lack of a copper braid probably means you are using CATV cable, not CCTV cable. Check the center conductor - if it bends relatively easily, it is copper; if it is very stiff, it is probably clad (copper coating on steel).

 

You can also use a small magnet to test the center conductor. If it is clad, it is not suitable for CCTV.

 

RG-6 and RG-59 are both 75 ohm cables, along with RG-179 (mini coax) and RG-11 (large coax). The difference between them is the DC resistance. The larger the diameter of the cable, the lower the DC resistance and therefore, the longer it can be run without excessive signal attenuation. For short runs, there is no practicle difference between the types. RG-179 is usually suitable for runs up to 100ft.; RG-59 can be run up to 750 ft.; RG-6 can be run up to 1000 ft. and RG-11 can be run up to 1,500 ft.

 

This assumes the cables are all constructed using 100% copper conductors. Aluminum and steel have a higher DC resistance per foot and will attenuate low frequency signals more than copper.

 

You might ask why cable manufacturers don't make all cables out of solid copper. The main reason is that high frequency signals exhibit what is know as the "skin effect". This means that the higher the frequency, the more the signal travels on the outside surface or "skin" of a conductor.

 

With very high frequency signals (including TV channels and FM radio), the majority of the signal travels on this skin. With the price of copper (over $3.00/lb) versus steel wire (approx. $.20/lb), it makes sense to produce copper-coated steel wire (clad) for high frequency applications. This is despite the higher production costs of the cladding process.

 

Also, steel is stronger and more resistant to stretching than copper. This makes copper clad steel cable attractive because if a cable is stretched, its impedance and resistance are affected.

 

The downside to steel is the higher DC resistance it has than than copper. CCTV video signals are low frequency; as are audio and AM and LW radio. These applications require solid copper since the signals travel more towards the center of the wire.

[rory 0]

More prone to interference, I have used it (way) in the past, but havent had to in years (back in the day when that was all we could find in nassau), and the ones I did came out okay, but a couple runs do experience occasional interference issues - issues I would not have with RG59. RG59 Siamese is now readily available where I live.

[CollinR 0]

You can also just splice the Cat5 and go all the way to the camera and put the balun. No matter how you send the feed the fewer connections the better.

 

Of course this assumes you are using a single camera balun rather then a 4 port jobber.

[survtech 0]

More prone to interference

What is?

[rory 0]

More prone to interference

What is?

 

RG6U

[boybloo 0]

The RG6 I've used is copper clad steel core and 77% aluminum shielding. Well I guess it has to go.

 

Our local home center has this wire doitbest dot com SKU528931 (couldn't post a link - haven't been around long enough)

 

I was told that it has copper shielding any chance it's 95% - the packaging did specify (according to sales person)

 

I'm in Rory's neck of the woods - Rory any idea where I can get the right stuff?

 

Also what are my options as far as the RG6 BNC connectors I can’t return?

 

1) Can I put a piece of electrical or Teflon tape around the end of the RG59 so that there is a more snug fit?

2) Can I use RG6 copper/copper on the camera end where stiffness is not an issue and RG59 on the DVR end?

 

Oh I didn’t know that I could connect the balun directly to the camera. That would work for 5 of my 8 lines. In the case where I have to add wire I was going to run coax from that point. Is it ok to join Cat5? If so should I solder or can I crimp the wires?

[rory 0]

sent you a PM.

 

You can also use Beanies to join the Cat5 cable, same people I PMed you about have those, cant buy them anywhere else on the island though. Or you could get an enclosure and use barrier strips or terminal blocks - you can get them right at Radio shack, or even a Punch block.

 

[boybloo 0]

I have beanies but I would prefer to use some of what ever that was you posted the picture of. It would make it easier to organize wires. What's that called? Do you need a tool to work it?

[survtech 0]

I have beanies but I would prefer to use some of what ever that was you posted the picture of. It would make it easier to organize wires. What's that called? Do you need a tool to work it?

It's a barrier strip. Just a small flathead screwdriver.

 

You can use "telephone wire splice connectors" (Radio Shack Catalog #: 64-3080 or equivalent):

 

Or "beans" (ICO-RALLY Part Number: 7920 / MCM Electronics Part Number: 95-670):

 

Or barrier strips (ICO-Rally and others).

 

Or you can use "66" or "110" punch-down blocks:

 

(requires a punchdown tool)

[boybloo 0]

I went with the conventional barrier strip. you know the black ones with screw terminals on the two sides but I don't think I'll be able to use them on the camera side because of the short (3" - 4") pigtails I have for power. Is it worth the trouble of souldering a piece on?...Nah, I'll just use the beanies.

 

One more issue. I planned to double up the cat5 for power but I've been told that there is probably no benefit to it. Anyone out there with proof positive (or at least an opinion) one way or the other?

[rory 0]

Far as I know, you cant run 12VDC 200', least not on 18AWG, let alone cat5. Even if you double up the pairs, it wont double the wire gauge.

[survtech 0]

Here is a link to a wire distance calculator for 9VDC, 12VDC and 24VAC.:

http://www.video-insight.com/Support/Tools/Wire-Length-Calculator.aspx

[rory 0]

yep, sorry should have mentioned depends the cameras current draw.

[boybloo 0]

Don't know that it matters but the power consumption is pretty low 12V, 1.4W & 300mA.

 

I got that doubling up idea from somewhere around here. The cameras have been running on single runs of Cat5 for a few years. The quality of the video was poor so I’ve concentrated on the video side of the issue, trying to improve on the existing setup.

 

I've learned a lot here but it appears that power is another issue and I have still more to learn.

 

What is the next most reasonable course to take? Bearing in mind that the Cat5 is already in place should I finish the installation as I planned with double Cat5 for power? If the Cat5 is really bad I can always move the power supply from my office to the stores (location of the cameras). In that case the longest run will be 80ft. I've checked the calculator and 18 guage is needed. I could make those runs the next time I have energy to burn.

 

Is there any info available on how double 24 guage rates. If it rates like 18 then I’m ok

[rory 0]

I would power the cameras locally, at the camera location that is. If there are a few of them in the same general location, or they go the same general route, you could power several of them at one location still. If the stores have a utility room or closet, office etc, could run them into that and place a Distributed power supply there.

 

Figuring even doubled up that is still 22 gauge wire, at 300ma and 12VDC, max distance according to the link provided is 124'. Just for information, thats another reason we like to use 24VAC, it can be used at almost double the distance of 12VDC.

 

Rory

[survtech 0]

Is there any info available on how double 24 guage rates. If it rates like 18 then I’m ok

Two 24-gauge wires can be run approximately twice the distance of one (3 = 3, etc.).

 

24 gauge is 25.67 ohms per 1000 ft. and can handle a maximum power of 3.5 amps. Two 24 gauge wires would be 12.84 (25.67/2) ohms per 1000 ft. and can handle a maximum power of 7 amps (3.5 x 2).

 

22 gauge is 16.14 ohms per 1000 ft. and can handle a maximum power of 7 amps.

 

Since two 24 gauge wires together is a lower resitance than one 22 gauge wire, there would be less voltage loss per foot and they could go farther. The equivalent would actually be 21 gauge which is 12.8 ohms per 1000 ft. (though I dare you to find it)

Edited September 13, 2007 by Guest

[rory 0]

Is there any info available on how double 24 guage rates. If it rates like 18 then I’m ok

Two 24-guage wires can be run approximately twice the distance of one (3 = 3, etc.).

You sure about that? I was told differently in the past, that doubling up does not make it a thicker gauge, or at least it does not double it. Perhaps 24 gauge would be more like 20 gauge when doubled up, something like that.

[survtech 0]

Voltage drop is the key and that is affected by resistance. Since paralleling two equal resistances equals 1/2 the resistance of one, the wire would drop the same amount of voltage in twice the length, assuming the current draw remains the same.

 

here is a link to a wire gauge chart:

http://www.powerstream.com/Wire_Size.htm

 

That's the theory, anyway. In practice, I don't like to exceed 80% of any published rating so call it 1.6 times the rated distance.

 

By the way, wire length charts and calculators are usually calibrated so that the voltage drop is 10% at the maximum length specified. Assuming you start with exactly 12.0 volts, the equipment at the end would be getting 10.8 volts.

[rory 0]

ok thanks, yup makes sense. Still thats only 78' and if doubled .... 150'?

(edit, so more like around 140' if using an 80% mark?)

 

I guess it also depends if the camera can even handle 10 volts .. some can .. dont know if the budget ones can though.

[survtech 0]

ok thanks, yup makes sense. Still thats only 78' and if doubled .... 150'?

(edit, so more like around 140' if using an 80% mark?)

 

I guess it also depends if the camera can even handle 10 volts .. some can .. dont know if the budget ones can though.

125 ft. (78 x 2=156 x .8=124.8 ).

 

Most equipment is rated to operate at the rated voltage +/- at least 10% (except Dallmeier cameras that are rated at +/- 5% ) (I blew one up using a 13.8 volt Radio Shack power supply).

Edited September 13, 2007 by Guest

[rory 0]

ok thanks, yup makes sense. Still thats only 78' and if doubled .... 150'?

(edit, so more like around 140' if using an 80% mark?)

 

I guess it also depends if the camera can even handle 10 volts .. some can .. dont know if the budget ones can though.

120 ft. (150*.8=120).

 

LOL roger that ... so 80% of the total. In any event it wont make his mark.

 

Now the question is .. what if he trippled up!? Since the cat5 has 4 pairs, and only 1 is for video. Would that be 3 x 78 * .8 = 187' .. man but still that would be under 200' or just pushing it. Also, what about interference from the power in the same jacket as the video, or I guess that will depend on his baluns?

 

Its a pity the cameras arent 24VAC!