Video Cables, Connectors - and formats

  • Thread starter Thread starter rob aylestone
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rob aylestone

rob aylestone

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I now use lots of BNC cables, and things there are a bit weird. Some cables have moulded on ends that are mechanically terrible and a sideways yank just snaps them off! We have crimped, clamped and moulded to cope with. The pins are different sizes on 75 and 50 Ohm versions but kind of fit. The Chinese ones that have crimped ends seem pretty decent. Cables are very different though. Stiff vs flexible, thin vs thick and frequency response/cable cables are a pain. I get some made up by Canford Audio - UK broadcast supplier, so I I want 40m of 12G capable cable, there is no way I can afford the tooling required to put the connectors on, so I pay them to make them up. 30m, another common length for me is from them too, but 12G will cope with my normal 20m cheaper cables. It makes all the people who wimp on about how audio cables sound better or worse than others look pretty silly. Squirt 12G video down a cable with high attenuation, questionable impedance and a poor frequency response and your kit looks at it and decides to not let you even try! I'm happy with dirt cheap XLRs, but grumble at spending huge amounts of money on a working and tough video one!
 
rob aylestone said:
Squirt 12G video down a cable with high attenuation, questionable impedance and a poor frequency response and your kit looks at it and decides to not let you even try! I
Click to expand...
Side question - You Shoot video in 12G?
 
12G? Yes, on demand. The cameras and switchers can run in HD mode through to HD - or you can do both - for the live switching and streaming, you can set the cameras to send out 1080 HD, and then I also record that format to SD cards. The alternative is to record to SSD hotswappble drives in 12G. The data rate though is crippling. CFast 2 cards and SD cards, but you format a disk and see something like 17 mins in the display, so two cards give half an hour - and the cards are crazy priced. In honesty, three clients asked for Ultra HD this year. The rest didn't actually ask at all. Worse is that if you cut cameras live, you will make mistakes, so my usual system is to record on 3 cameras, and the switched video to SD card. If I mess up, you can then bring in the camera isolated media and repair it. I split this from coolcats Neutrik connector topic
 
I am a bit confused Rob when you say "no way I can afford the tooling to fit BNCs" ? I used to solder good quality BNC plugs to cables for J-Beam Antennas Npton for a few weeks. Yes, BLOODY fiddly and you have to prepare the ends of the cable to the exact cut dimensions but it gets easier with practice. Also fitted the huge "N" plugs using a resistance solder machine.

I would have thought your soldering skills easily the equal of mine? (and MUCH better now!)

Dave.
 
I have wired up a lot of BNC connectors. We called it an intelligence test, and it never got easy.
Different brands had different components, with of course, no instructions.
I've just bought a couple of manufactured BNC cables, for ADAT clocks.
Am rather relieved to be excused any wiring.
 
Slouching Raymond said:
I have wired up a lot of BNC connectors. We called it an intelligence test, and it never got easy.
Different brands had different components, with of course, no instructions.
I've just bought a couple of manufactured BNC cables, for ADAT clocks.
Am rather relieved to be excused any wiring.
Click to expand...
Ah yes! Different folks had different strokes but, for my own use I bought from RS Comps. Expensive but came with a very clear diagram. Now I think of it, J Beams had a very clever cable cutting machine so they came cut to length with ends prepared to a fraction of a gnat's undercarrige. Still had to make sure you got clamp nut, neoprene bung and shield plate in the right order plus those fiddly bits of PTFE!

Always enjoyed making up cables though.

Dave.
 
Dave - you don't even get the option of solder terminations for 3G or 12G video. They are all crimps. 50Ohm versions for 1GHz are now also crimp. You shove the cable into a cutter with multiple blades - it trims the end of the cable - centre conductor, the dielectric and the screen to the precise dimensions required, then you crimp the centre conductor to the pin, then push the cable end in, and the tool then secures the screen. Slide the cover down where it locks. I've put hundreds on for installs with somebody elses tooling - but now I don't have the access.
 
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