Greetings. We bought an IO through ProMax, and were told that the standard BNC cable supplied with the cable kit can be used for SDI. But I've always been under the impression that SDI required a different type of BNC cable. Can anyone give me a definitive answer?
I buy all my 75 Ohm cables from http://www.bleujeanscable.com. They offer a very wide variety of cable types and connector combinations. I almost always use Belden 1694A which is moderately flexible. More flexible cables are also available.
Nothing special, just 1's and 0's. Better quality means less chance of interference by some rf signals that could cause disruption in signal but rare. I use 7291 or 82/81 cable but only personal preference.
Using Belden as the reference (there are plenty of other good cable companies like Gepco, and Canare), SDI Video cable is called Belden 1505A.
It is double shielded like the old Belden 8281, but it is flexible, and easy to terminate and use, so 8281 has been pretty much outdated, and everyone uses 1505A.
Belden 1694 is Hi Def Video cable. It is thicker (RG6, unlike 1505A which is RG59 type), but still pretty flexible. You certainly can use 1694 for SDI.
If you look at the Belden cable guide, you will see that many of these cables can be used based on the distance you are running these cables. Belden 1505A (the SDI cable) can be used for HD up to 300'. Since all my jobs almost never exceed 100' runs, I always use Belden 1505A for both HD and standard SDI installations. It works just fine.
If you want skinny cable, Belden 1855A is also qualified for SDI, however most integration houses use this for AES audio that terminates with BNC connectors.
Now the bottom line - in a pinch, I have used the generic cheap crap Belden 8241 standard analog video cable for short runs (under 20'), and have gotten away with it. You are transmitting square waves with SDI signals, and you can get away with a short run of this cheap cable type with no problems. As many of us have seen, the same applies to digital Audio - AES/EBU. For short runs, you can get away with standard audio cable, instead of 110 ohm digital audio cable with no problems.