# RCA Video run - ASAP

#### Charc

##### Well-Known Member
I need to make a decision ASAP on video projection.

We need about a 100 or slightly longer video run of RCA.

Does anyone know which specs, or vendors I should be looking at online for this cable? We'll be paying expedited shipping, I'm sure. I called Tweeter and they said it'd cost 100 or so, and be ready Monday or Tuesday. So yea, looks like the internet might be cheaper.

So, anyone, thoughts?

I'll need to decide in the next hour or two.

Thanks.

#### icewolf08

CB Mods
I would call your local RadioShack. This is not an uncommon item, and should be readily available locally. You can probably also find this cable in Home Cheap-O, Lowes, or any electronics store. $100 isn't outrageous. Can you get it cheaper, probably, but they are common. You don't need to get monster cable either, simple, plain old RCA will work. #### soundlight ##### Well-Known Member Buy a bulk spool of cable from an electrical supply place (heck, even lowes might have it) and pop on two RCA connectors from radioshlak. #### SHARYNF ##### Well-Known Member go to radio shack or your local cable company and get 100 feet of rg59 or 5g6 coax, it will have f connectors on it, then get two adaptors that convert F connectors to rca In a pinch you could wire on rca connectors but the adaptors are easier sharyn #### soundlight ##### Well-Known Member go to radio shack or your local cable company and get 100 feet of rg59 or 5g6 coax, it will have f connectors on it, then get two adaptors that convert F connectors to rca In a pinch you could wire on rca connectors but the adaptors are easier Or this - it'll work just as well...and you'll be able to use it as an F run if you ever need an F run for coaxial video for another application. #### mbenonis ##### Wireless Guy Administrator Premium Member I second the idea of getting a long run of RG6 and two F to RCA adaptors for it. It'll be cheaper and of higher quality than what you might get elsewhere. #### fosstech ##### Active Member BNC would be better in my opinion. Quick connect/disconnect and secure locking. Not the case with F which usually requires fiddling to get it tight. #### SHARYNF ##### Well-Known Member The problem you run into is that most of the rg59 cable sold in RS or where ever is not going to have bnc, and the cable company typically does not use bnc on their rg6, and bnc to rca adaptors are harder to find. #### derekleffew ##### Resident Curmudgeon Senior Team Premium Member I agree totally with SHARYNF. Here's the link to the big orange store.$63 for a 500' spool. I know you need 1/5 that, but they don't say what the price per foot is, but I'm guessing around 25¢/ft. Although RG-59 is less expensive, go with the RG-6. Also buy the best crimpers you can afford, and the crimp-on "F" connectors. I kind of agree BNC would be better, but more expensive and harder to find.

And thanks for pointing out that "link" chain icon. As you can see, I've used it a bunch.

#### avkid

##### Not a New User
Fight Leukemia
Er, I'm pretty sure I bought the lower-quality cable...
Oh well, the price was right, 40 dollars w/ overnight shipping included...
No, the price was wrong.
If you paid less than \$.75 a foot it is most likely garbage.

#### derekleffew

##### Resident Curmudgeon
Senior Team
avkid, are you saying that "BICC 500 Ft. Black RG 6 Quad Shield Coaxial Cable" (the link I posted) at 12.6¢/ft. is no good? I realize it's not Belden, Pomona, or Monster brands, but I've had no problems with it in my domestic use.

Next time HBO is in for a Boxing Match, I'll ask their engineers what they recommend. You'd trust their opinions, right?

#### avkid

##### Not a New User
Fight Leukemia
avkid, are you saying that "BICC 500 Ft. Black RG 6 Quad Shield Coaxial Cable" (the link I posted) at 12.6¢/ft. is no good? I realize it's not Belden, Pomona, or Monster brands, but I've had no problems with it in my domestic use.
Next time HBO is in for a Boxing Match, I'll ask their engineers what they recommend. You'd trust their opinions, right?
Let me clarify.
From a consumer mass merchandiser.

#### museav

##### CBMod
CB Mods
Departed Member
First, what is the source? Running composite video to a projected large image may be the least expensive approach but may not give the desired image quality. On many satellite receivers, DVD players, etc., especially newer consumer models, the composite video output is sort of a last resort and not a lot of concern or expense goes into it.

Second, while a bit off topic, what is the application? You may have already addressed this or may have a commercial service, but warning bells go off when someone mentions projecting a sporting event, so make sure that any rights for such a presentation or payments for those rights are covered.

If this is a one time thing, then buy preterminated cable. To properly crimp you have to get the right dies and connectors for the specific cable. A decent die and crimper will run more than the prices you are identifying for the cable. Worth it if you do it a lot, but probably not for one time. I agree that it may be best to buy BNC terminated cables and use BNC-to-RCA adapters (I bought every one my local Radio Shack had when they closed).

What is the cable path? Don't forget to consider if plenum cable is required. Not an issue if you run the cable across the floor (although that could be a trip hazard) but if you run it above a ceiling and the cable is not in conduit, plenum rated cable may be required by code.

Finally, while they may both be RG59 or RG6 cables, there are differences between RF/CATV/MATV cable and baseband video cable. Manufactured cables terminated with F connectors are probably RF/CATV/MATV cables, while those terminated with BNCs are likely video cables.

#### kwotipka

##### Active Member
Here is my 2 cents and I apologize for being late (I have been on the road the past few weeks).

If you are running CATV RF (ie. cable or commonly labeled MATV) then 60% Al Braid 75ohm cable will work.

If you are running any other kind of RF, especially if it is from a transmitter, then it needs to be 50 ohm cable and it better be terminated correctly.

If you are running any sort of composite video, it should be 100% Cu Braid and at least an RG6 if it is at any length. BNC is the best way to connect it, but I have used other methods and adapters.

If you are running any type of component video (S-VHS (Y/C), Y/R-Y/B-Y, RGB, etc.) then you need to have specialty cable because all of the signals have to get to the end of the cable at the same time. You can't just stretch out 2,3 or 5 pieces of coax and expect to get a clean signal out of the other end.

Now, all that said, obviously component video is better. The consumer digitals all have relatively short distance limits. If you are running SDI then you know the answers already. I have had very good luck with Comprehensive brand component cables. They are built very well and have a lifetime warranty.

On the rough and ready side of things, I have also run composite video down 300' of an audio snake channel. I have run RGBHV (computer video) down CAT5 cable. It really depends on how bad you want it and what it can look like on the other end.

Hope it helps.

Last edited by a moderator:
derekleffew

#### museav

##### CBMod
CB Mods
Departed Member
If you are running any type of component video (S-VHS (Y/C), Y/R-Y/B-Y, RGB, etc.) then you need to have specialty cable because all of the signals have to get to the end of the cable at the same time. You can't just stretch out 2,3 or 5 pieces of coax and expect to get a clean signal out of the other end.
Timing is potentially an issue for analog video, but the reality is that that it is much misunderstood. Here's a relevant discussion from one web site:
Timing is Good, But...

"Timing" is a consideration in component video cable quality, and while it's meaningful, it's often over-emphasized. The three cables in a component video cable should all be of the same electrical length--which is to say, it should take a signal the same time to travel through each of them as it does to travel through the others. The speed at which a signal travels through a cable depends on two things: the physical length of the cable, and the consistency of the dielectric material. If the manufacture of the dielectric is highly consistent, and the cables are cut to equal length, then timing variation between cables will be insignificant. This requirement for a consistent dielectric, as it happens, is directly tied to "impedance tolerance," of which we spoke above. The impedance tolerance reflects the consistency of the dielectric, and so the tighter the tolerance, the lower the potential for timing error.

But timing, as we've suggested, is often a bit over-sold. The broadcast-quality benchmark standard is that timing should be within 40 nanoseconds (abbreviated "ns") from one channel (that is, one cable in the set of three in a component video cable) to another. Using a cable having a tight impedance tolerance of +/- 1.5 ohms, or +/- 3 ohms, it's impossible to get more than a few nanoseconds per hundred feet of timing variance from one cable to another, if those cables are cut to the same physical length. Cutting them to different lengths, of course, would do the trick--but it takes a large discrepancy in cable lengths to make up a 40 ns difference. Consider, for example, Belden 1694A. Electricity travels down the center conductor at 82% of the speed of light (this is what's called the "velocity of propagation" of the cable), and so takes 1.24 nanoseconds to travel one foot. To cause a 40 ns delay by cutting 1694A cables to different lengths, one would have to make one of the cables about 32 feet longer than the others--and the resulting component video cable would still, albeit just barely, be within the broadcast quality standard.
Since bundled coax is really simply multiple coaxes in a common jacket, the differences in dielectric constants and differences in length caused by cable routing and terminations are pretty much the same as with multiple individual coaxes. The reality is that with any reasonable level of care you can get very acceptable results with multiple individual coax runs and I have seen this in application in numerous production and broadcast facilities.

#### kwotipka

##### Active Member
Timing is potentially an issue for analog video, but the reality is that that it is much misunderstood. Here's a relevant discussion from one web site:
Since bundled coax is really simply multiple coaxes in a common jacket, the differences in dielectric constants and differences in length caused by cable routing and terminations are pretty much the same as with multiple individual coaxes. The reality is that with any reasonable level of care you can get very acceptable results with multiple individual coax runs and I have seen this in application in numerous production and broadcast facilities.

I think the key takeaway from this post is the fact that it was seen done in "numerous production and broadcast facilities". When this was done, it was done with cable that more then likely came from the same lot. It may have also been done with the aid of a meter that will measure velocity factor across multiple cables and trimmed for length. It doesn't matter what type of signal is transmitted but if it has to arrive at the same time as other signals, the timing matters. CAT5/6 networking, HDMI/DVI, and yes even analog. While true, a CAT5 cable that has some timing issues will still operate, it will not do it as effecient as one that is within spec. In multi conductor data cables you will see artifacts. In analog video you see this as what looks like a registration issue as you will have a "color band" or misalignment in a white grid or ghosting around objects. On site, this is usually caused by a cable that someone has run over too many times with road cases, etc and has caused damage to the dielectric in one of the runs somewhere in the cable.

An interesting test is if you have a cat5 cable certifier, make up a cat5 to BNC adapter. I don't know how accurate it is overall, but you can really see the velocity factor difference between the individual coax in damaged cables.

What I was trying to avoid without going into this detailed of an explanation was to not have someone pull out 3/5 runs of different type / age coax and hope to get an acceptable result.

On a side note, what I think is great about this forum is the diversity of user level. I wish I had access to this type of information when I was 18 and learning broadcast video by trial and error. "Shout out" to Jim Edwards of Tektronix for his patience and 800 number back in those days.

kw

#### museav

##### CBMod
CB Mods
Departed Member
My mistake, for some reason I took the comment "You can't just stretch out 2, 3 or 5 pieces of coax and expect to get a clean signal out of the other end." to be referencing the relative lengths rather than multiple different cable types.