I was I'm in the market to buy a pair of 15-pin to 5xBNC SVGA cables. But i'm seeing all sorts of price ranges from $25.00 up to a ridiculous $80.00 for 10-foot cables. The websites i've been to also mention ferrite cores and sheilding and whatnot but i'm not sure if they actually matter all that much.
I'm asking what I should look for in a BNC cable.
I haven't personally purchased BNC cables, but I have gone cable shopping for my component video cables. I ended up buying bettercables.com silver serpent cables. Now I went to the extreme in buying the best I could find, but that depends mostly on how picky you are. There is a noticeable difference when using expensive cables than when using cheaper cables, but often not noticeable enough unless viewing them side by side. This also depends greatly on your other equipment. Buying the best video cables in the world isn't going to make a 21" screen look much better. The bigger and better the screen, the bigger difference the cables make.
With that all said, I would recommend getting cheap cables if you have a screen below 32". For screens above 32" I would get mid-range cables like Monster Cables if you aren't super picky. If you have a large screen and want the best, I would go to www.bettercables.com and get the best for a decent price.
I know this doesn't give any specifics on any of the different cables. It seems that each company uses different names for similar things. You want one that is shielded, has good connectors that fit snugly and won't break, and you want the conductive wire to be built well of a good material. Silver is one of the best and it allows for thinner wires of better quality, but it costs a premium.
BNC connectors are a legacy feature from the days before the DB-15 connector became widely accepted as the VGA standard. Today most DB-15 video cables use the same 75 Ohm mini coaxial cable as found with the BCN connectors. .
With any connector (BNC or DB-15) there is a possibility of an impedance miss match that could send ripples up and down the video cable. The ripples can be amplified by the video amp and show as shadows or ghosts after light to dark or dark to light transitions on the screen.
Most manufacturers are taking the connectors (BNC and DB-15) off the monitor all together and permanently attaching the cable to the monitor. By doing this they can solder the cable wires directly to the video amplifier board inside the monitor, effectively eliminating any chance of impedance miss match on the monitor end from a connector. An added benefit to a permanently attached cable is, you will never loose it, should you move your system. In any scheme there are trade off. The trade off in permanently attaching the cable is that if the cable should go bad, you need to send the entire unit in for service. My experience says that occasionally cables do break, but the failure rate of cables is very low.
Even if you use a BNC cable, the end that attaches to the video card is still the VGA DB-15. The impedance mismatch at that end of the cable can cause the same types of ghosting affect. If both sides had BNC connections then there would be some improvement. Someone much wiser than I said, it doesn’t make sense to anchor a bridge in concrete on one side and tree vines on the other.
Chief Hardware Engineer