Brandon Whiteside Posted March 17, 2012 Report Share Posted March 17, 2012 Hey everyone, Im trying to find out if there is a specific grade of cable and BNC connector that is used for HD SDI cables. Here is my latest project: I am flying a cinema products sk (I know everyone hates it but I have retrofitted a Marshall 7" to it with 15mm rods and it will fly a red one, so it currently works for me) and I want to re cable it for HD SDI. It has a BNC on the sled and a lemo where the post connects to the base. Anyway, let me know if you may have any pointers or tips. Thanks Quote Link to comment Share on other sites More sharing options...
Premium Members William Demeritt Posted March 17, 2012 Premium Members Report Share Posted March 17, 2012 I believe the universal characteristic of all HD-SDI cables is 75 ohm resistance. The other characteristics give varied results. I prefer Belden 1505 and Belden 1694a for HD-SDI, although 1694 is solid copper (not stranded), so not ideal if it's in a post that collapses and expands. VERY STIFF. 1505 might be your best bet? 1 Quote Link to comment Share on other sites More sharing options...
Brandon Whiteside Posted March 17, 2012 Author Report Share Posted March 17, 2012 Stranded would definitely be better...at least for soldering. I will look into it and report back as soon as I make it happen. Thanks! Quote Link to comment Share on other sites More sharing options...
Premium Members William Demeritt Posted March 17, 2012 Premium Members Report Share Posted March 17, 2012 I may be wrong, but I'm pretty sure HD-SDI requires crimping BNC connectors and bulkheads, not solder BNC. However, yea, stranded is easier to work with, but you require a lower AWG to match the transmission capability of a higher AWG solid copper core. Quote Link to comment Share on other sites More sharing options...
Moderators Louis Puli SOC Posted March 17, 2012 Moderators Report Share Posted March 17, 2012 "Anyway, let me know if you may have any pointers or tips." Hi Brandon I am looking at upgrading to HD as well .I am looking at this cable Belden179DT SDI/HDTVRG179 . http://www.sjmediasystem.com/179dt-b-b-6.html I will let you know how I go . Quote Link to comment Share on other sites More sharing options...
Premium Members Afton Grant Posted March 18, 2012 Premium Members Report Share Posted March 18, 2012 I may be wrong, but I'm pretty sure HD-SDI requires crimping BNC connectors and bulkheads, not solder BNC. However, yea, stranded is easier to work with, but you require a lower AWG to match the transmission capability of a higher AWG solid copper core. I solder all my HD BNC cables. Never had a problem. Why would that make any difference....especially a negative one? Quote Link to comment Share on other sites More sharing options...
Premium Members Eric Fletcher S.O.C. Posted March 18, 2012 Premium Members Report Share Posted March 18, 2012 I may be wrong, but I'm pretty sure HD-SDI requires crimping BNC connectors and bulkheads, not solder BNC. However, yea, stranded is easier to work with, but you require a lower AWG to match the transmission capability of a higher AWG solid copper core. I solder all my HD BNC cables. Never had a problem. Why would that make any difference....especially a negative one? Crimping actually is the preferred method since it's a mechanical connection Quote Link to comment Share on other sites More sharing options...
Premium Members John Saunders Posted March 18, 2012 Premium Members Report Share Posted March 18, 2012 If you like 1694A they also make a flexible version that is really nice and has a stranded core. It's 1694F and is pretty pricey but great cable. I have a spool of it if anyone wants to try it or needs a cable made. It's pretty big cable though and may not be the best for a center post cable. We always crimp our cables for what it's worth. I think the main thing is that you make sure you are using 75 ohm connectors and cable that is rated for at least 1.5 ghz bandwidth. Hope it helps. Quote Link to comment Share on other sites More sharing options...
Premium Members John Saunders Posted March 18, 2012 Premium Members Report Share Posted March 18, 2012 Oh and for small hd sdi cable we use 1855a. I think it is still a solid core but due to its smaller size it is pretty flexible. Also if you are going to solder it to a lemo it would be much easier than 1694F. Quote Link to comment Share on other sites More sharing options...
Brandon Whiteside Posted March 18, 2012 Author Report Share Posted March 18, 2012 Wow thank you for all of the replies. I'll do my research and report back. John, are you in LA? Quote Link to comment Share on other sites More sharing options...
Premium Members Afton Grant Posted March 18, 2012 Premium Members Report Share Posted March 18, 2012 Crimping actually is the preferred method since it's a mechanical connection Guess I'm just curious at this point. My background in engineering consists of a couple books on my shelf that I pretend to have read. Why is a mechanical connection better than one where the two conductors are, for lack of a better term, fused together with metal? It's just counter intuitive if that's the case. Quote Link to comment Share on other sites More sharing options...
Premium Members John Saunders Posted March 18, 2012 Premium Members Report Share Posted March 18, 2012 Wow thank you for all of the replies. I'll do my research and report back. John, are you in LA? No I'm on the east coast in MD. If you want a couple feet of cable just let me know I can send you some, I know it can be a pain to get small quantities of it. I can also throw some bncs on it for a few bucks. Quote Link to comment Share on other sites More sharing options...
Premium Members John Saunders Posted March 18, 2012 Premium Members Report Share Posted March 18, 2012 Crimping actually is the preferred method since it's a mechanical connection Guess I'm just curious at this point. My background in engineering consists of a couple books on my shelf that I pretend to have read. Why is a mechanical connection better than one where the two conductors are, for lack of a better term, fused together with metal? It's just counter intuitive if that's the case. I'm not an engineer either although I have been making cable my whole life. The only thing I can think of about soldiering bncs is that it might change the resistance of the connection thus affecting the 75 ohm rating. Not sure though and I do know that a properly soldiered connection is normally stronger than a crimped on. I am not sure how you soldier the sleeve though seems like it would be tough. I do like soldiering me some cables though:) Heres the last big panel I worked on: 80 something pairs of audio 2 snakes 2 multipins 24 paralleled xlr connectors Loads of fun.... Quote Link to comment Share on other sites More sharing options...
Premium Members Afton Grant Posted March 18, 2012 Premium Members Report Share Posted March 18, 2012 I'm not an engineer either although I have been making cable my whole life. The only thing I can think of about soldiering bncs is that it might change the resistance of the connection thus affecting the 75 ohm rating. Not sure though and I do know that a properly soldiered connection is normally stronger than a crimped on. I am not sure how you soldier the sleeve though seems like it would be tough. But any contact between two conductors affects the overall resistance slightly. Again, it's just intuitive to think that a connection made by heat and melting metal would make for less resistance than a connection made by only pressure. Otherwise, why are so many other connections in electronics (wires, circuit boards, components) soldered rather than plugged or crimped? I actually don't solder the sleeve. I use epoxy and shrink tubing to hold things in place. Quote Link to comment Share on other sites More sharing options...
Premium Members John Saunders Posted March 18, 2012 Premium Members Report Share Posted March 18, 2012 I'm not an engineer either although I have been making cable my whole life. The only thing I can think of about soldiering bncs is that it might change the resistance of the connection thus affecting the 75 ohm rating. Not sure though and I do know that a properly soldiered connection is normally stronger than a crimped on. I am not sure how you soldier the sleeve though seems like it would be tough. But any contact between two conductors affects the overall resistance slightly. Again, it's just intuitive to think that a connection made by heat and melting metal would make for less resistance than a connection made by only pressure. Otherwise, why are so many other connections in electronics (wires, circuit boards, components) soldered rather than plugged or crimped? I actually don't solder the sleeve. I use epoxy and shrink tubing to hold things in place. If it works for you thats all that matters I guess. To each his own. Seems like more work than just crimping it, but the tooling can be a little bit of an investment at first. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.