Richard Ragon Posted August 3, 2011 Report Share Posted August 3, 2011 I'm going to be installing some video monitors into a rack mount. I'm thinking of placing a 'patch panel' on the other side of the rack. So, I guess I'll need to make up some smaller patch cables that go between the monitor(s), and the patch panel. What is the ohms on the video cables? 50ohms, 75omhs? Does it make a difference? Have you guys made your own BNC to BNC cables? Has anyone done this? Thanks -Richard Quote Link to comment Share on other sites More sharing options...
cmgoodin Posted August 3, 2011 Report Share Posted August 3, 2011 Richard, Video cables should always be 75 ohm for baseband video. Also use 75 ohm BNC connectors. There are a lot of cheap 50 ohm BNC cables in the surplus market from the days of 10 base T Eithernet. 50 ohm cable can be used for antenna connections. It will work for video but you may see some ringing (double images) or loss of brightness. depending on the lengths involved. Quote Link to comment Share on other sites More sharing options...
studiomprd Posted August 3, 2011 Report Share Posted August 3, 2011 " Have you guys made your own BNC to BNC cables? Has anyone done this? " Yes and yes. The newer compression connectors are best, and easy with the proper tools. Quote Link to comment Share on other sites More sharing options...
Marc Wielage Posted August 4, 2011 Report Share Posted August 4, 2011 Richard, you can get a crimp-on tool and a bunch of BNC connectors fairly cheap at PacRadio and the usual suspects. I used to make all my own BNC and phono cables in the old analog video days. RG79 cable is cheap and widely available. Belden makes a super-flexible type that's good on a rack, but there are heavier-duty versions with stiffer shields that will hold up better in the field, especially dragged across roads and driveways. The trick is in cutting the cables just right, exposing just enough of the shield, and getting heavy-duty connectors. I liked the ones that give you a protective boot, which at least give you the illusion of safety. I think Kings was the one I settled on -- they're inexpensive but very well-made. --Marc W. Quote Link to comment Share on other sites More sharing options...
cmgoodin Posted August 4, 2011 Report Share Posted August 4, 2011 Richard, you can get a crimp-on tool and a bunch of BNC connectors fairly cheap at PacRadio and the usual suspects. I used to make all my own BNC and phono cables in the old analog video days. RG79 cable is cheap and widely available. Belden makes a super-flexible type that's good on a rack, but there are heavier-duty versions with stiffer shields that will hold up better in the field, especially dragged across roads and driveways. The trick is in cutting the cables just right, exposing just enough of the shield, and getting heavy-duty connectors. I liked the ones that give you a protective boot, which at least give you the illusion of safety. I think Kings was the one I settled on -- they're inexpensive but very well-made. --Marc W. You should use RG59B for standard Def video it is 75 ohm. RG79 is 125 ohm and should be used only for high band digital or HDSDI signals. For antenna RF or Eithernet use RG58 (50 ohm) cable or the heavier RG6 for higher frequencies. Here is a link to a good chart: http://www.admiral-microwaves.co.uk/coaxial-cable-types.php Quote Link to comment Share on other sites More sharing options...
Marc Wielage Posted August 5, 2011 Report Share Posted August 5, 2011 That must be where I got RG79 from -- the last time I used it, I was actually assisting with an HD-SDI install. (Miles and miles of it.) I agree, RG59 will be cheaper and better suited for composite. --Marc W. Quote Link to comment Share on other sites More sharing options...
Jay Rose Posted August 10, 2011 Report Share Posted August 10, 2011 ...The trick is in cutting the cables just right... --Marc W. Good electronics stores will have a cheap stripper made for RG59 in cable-tv installs. Little plastic thing that spins around the wire once, cutting the sheath, shield, and inner insulator in just the right places for a crimp-on F connector... turns out, if you then trim the center conductor, it's perfect for BNCs. Or search Amazon for "rg-59 stripper"... there are a few dozen, between $5 - $20. Quote Link to comment Share on other sites More sharing options...
Laurence Posted August 10, 2011 Report Share Posted August 10, 2011 Is it true that generic ones don't always work well and you need to get the right stripper for the particular brand of connector? Otherwise stuff don't fit the way it's supposed to and connections don't last? And it's best to stay away from the cheapest ones? Quote Link to comment Share on other sites More sharing options...
Marc Wielage Posted August 11, 2011 Report Share Posted August 11, 2011 I've got a reasonable heavy-duty RG59 stripper/cutter, and I think it was under $20. I like those better than the little plasticky doo-dads that spin around the cable. A lot depends on how many cables you intend to make. If it's just a half dozen, heck, you could do it with scissors and a razor blade if you're careful. The crimping is the hard part. --Marc W. Quote Link to comment Share on other sites More sharing options...
Jim Gilchrist Posted August 11, 2011 Report Share Posted August 11, 2011 If you're making tons of cables, it's worth investing in a quality stripping tool and Paladin makes several for different cable types and stripped lengths. They run between $60 and $90, if my memory serves. Once properly set up for the cable and connectors you're using, it takes about 5 seconds to properly strip each end of a piece of coax. Klein makes a coax stripper that's a little less versatile so it takes a little longer to use but it's also only $12 or so but will last forever. And I'll bet the Klein tool is available at places like Home Depot. Best regards, Jim Quote Link to comment Share on other sites More sharing options...
David Waelder Posted August 11, 2011 Report Share Posted August 11, 2011 I've used a number of different strippers from Paladin and other manufacturers, most on the cheaper side of the range. For daily professional use it makes sense to invest in something really good; for occasional use, any of the cheaper units are OK. But getting the stripper aligned so the blades exactly cut the insulation, and only the insulation, or cut through the shield, but not through the next layer, can be a bit tricky. I've adopted a practice of designating a stripper for a particular cable. Once I have a stripper working for RG-59, I never change it to do RG-8 or RG-58. I'll buy a new stripper and set it up for other cable. I now have a drawer with three strippers, each labeled for a particular cable. They're cheap enough that altogether the investment isn't that great and the money was spent over a period of time as I had need to do different cables. David Quote Link to comment Share on other sites More sharing options...
studiomprd Posted August 11, 2011 Report Share Posted August 11, 2011 " generic ones don't always work well " sometimes they do not, but my experience has been "usually work OK", though the rule still applies: "generally speaking, you get what you pay for". The compression connectors are superior. Quote Link to comment Share on other sites More sharing options...
berniebeaudry Posted August 12, 2011 Report Share Posted August 12, 2011 " generic ones don't always work well " sometimes they do not, but my experience has been "usually work OK", though the rule still applies: "generally speaking, you get what you pay for". The compression connectors are superior. +1 for the compression connectors. Quote Link to comment Share on other sites More sharing options...
Toy Robot Posted January 25, 2015 Report Share Posted January 25, 2015 This is an old thread, I know; however the following article directly relates to Richard's question in the original post: 50 Ohms, the Forgotten Impedance. Quote Link to comment Share on other sites More sharing options...
Hartley Posted January 27, 2015 Report Share Posted January 27, 2015 You might want to look at Canare connectors and their stripper and crimpers. Belden 1505A cable is very good and usually a little less expensive than Canare cable. I have used thousands of these connectors and can't remember a failure. They are money in the bank. The investment may be a little higher at the outset but you will have a tool that will last a lifetime. You can change out crimp dies and use it with a number of different connectors and cable. Quote Link to comment Share on other sites More sharing options...
Arn Posted March 31, 2015 Report Share Posted March 31, 2015 Hi, maybe a stupid question. Can 50 ohm's antenna signals pass trough xlr-cables? with a bnc-xlr connector. Idea is to use the xlr stage-reel to get the shark-fins closer to the set. guessing there will be to much loss of signal-strength... Quote Link to comment Share on other sites More sharing options...
afewmoreyears Posted March 31, 2015 Report Share Posted March 31, 2015 You would be correct... Quote Link to comment Share on other sites More sharing options...
Constantin Posted April 1, 2015 Report Share Posted April 1, 2015 Hi, maybe a stupid question. Can 50 ohm's antenna signals pass trough xlr-cables? with a bnc-xlr connector. Idea is to use the xlr stage-reel to get the shark-fins closer to the set. guessing there will be to much loss of signal-strength... You can do it, but as the bnc-xlr changer use your receiver. Use the long xlr to connect to your cart Quote Link to comment Share on other sites More sharing options...
Todd Weaver Posted April 16, 2015 Report Share Posted April 16, 2015 It depends on the signal. I wouldn't use it for high frequency stuff like video or RF. Those connectors have a specific value that shouldn't be trifled with and a loss in dB associated with every break in the cable as well as a drop in signal over cable length.. Quote Link to comment Share on other sites More sharing options...
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