Loop Sync Cables HDX HD Native

[frazzz]

Hi,

Some clarity would be appreciated here for the correct loop sync cables for HDX / HD Native systems using Avid HD IO.

I've attached a .JPEG of a male to male cable which I hope is correct - I know it is meant to be 75 Ohm - Some clarity on this and whether male to male connector is correct - Then I can get some - Thanks in advance

[Darryl Ramm]

Almost all BNC cables made/used are male to male and that's what you want here. All the panel mount BNC connections for word clock, loop sync, S/PDIF (yes that exists on BNC coax), MADI over copper coax, SDI video, composite video, etc. are female, so cables are male-male.

A proper "digital" coax is 75 ohm impedance and should have specific 75 ohm spec BNC connectors. Word clock, loop sync, S/PDIF on BNC coax, MADI on BNC coax, SDI video, etc. are all 75 ohms, but different cables can differ widely in loss and leakage specs and build quality. Ideally buy a good quality "digital" cable with brand name coax (e.g. Belden 1505F) and connectors. I get my BNC cables made by Blue Jean cables https://www.bluejeanscable.com.

[frazzz]

Hi - I found the place you get your cables from - I'm in UK so it's a bit of a long post!

Info. on specs is a bit sketchy at different online shops (even audio pro shops) so it's very difficult to know what is being bought or considered.

You mentioned a certain cable - 1505F - I've uploaded a snapshot of this - and is it upto 6G? - I'm not familiar at all with this as other regular interfaces / computer tech doesn't use these so it'll take a while to know more.

Would these cables do 100% for the HD IO's - There could be 3 of them with an OMNI! - As long as the specs are good and the "bandwidth" is sufficient for all out use then there should be no problems - Please comment - Thank you.

[JFreak]

There are really no hard requirements for this if your cable length is short. One time I had a broken cable and no spare, so i just used two standard wires to connect the boxes and it worked. Good quality cable becomes necessary when you are talking 50-100' runs, but few inches has no practical requirements.

^ also remember this is single cable length, not loop total length. Every connection terminates and the next one is another story.

Point being 90% of the "good quality" cable comes from the connector and how the cable is connected, 9% comes from logistics. Cable itself costs 1%. "Best quality" would be going to electronics store and ask someone to hand-solder the cable and put heat shrinks around the connector, but one dollar factory made cable works just as well.

[Darryl Ramm]

You should be able to pick up quality cables in many places. Companies there service the video/broadcast market often handle these higher-end BNC cables for SDI video. The more standard RG-59 coax will work OK for most clocking, but not higher bandwidth needs. But "RG-59" spec coax varies in quality, flexibility, construction etc. And for me Belden 5150F is just a much nicer cable at not much more cost. It has got very low loss at clocking frequencies, is robust but still nicely flexible. You can use it for simple stuff from like clocking up to fast SDI video, it's the one coax cable I choose to use for every 75 ohm cable I need. It's nice to have only one digital coax cable type.

Good coaxial cable assemblies should use all crimp, not solder and not screw on outer connectors.

The cables like 5150F have 75 ohm BNC connectors made for them, you can't just use any BNC connector or even any 75 ohm BNC connector connector. Canare and Amphenol make nice crimp BNC connectors for these. Blue Jeans uses the specific Canare BNC crimp connectors for 5150F (which cost a reasonable few dollars each for the connector).

A cable manufacturer need specific die tooling to crimp specific connectors, if you did this yourself it would cost several hundred dollars for the tool and dies. Blue Jean's and other manufacturers may use hydraulic crimpers that costs in the thousands. My biggest peeve with many coaxial cables is poor quality connectors/crimp jobs and cables typically fail/have issues at the connector. I used to make all my own cables it's just not worth it now for most standard stuff.

---

So yes the cables you configured on Blue Jeans will work fine if they are long enough for your needs. But I would hope you can find a local UK supplier.

I look at these cables as a low cost investment, a good cables gives reliability and peace of mind. Get what you need and some spares. Don't try to make them too short that they are stretched or bent sharply. You should be able to find local cable assembly suppliers or custom fabricators. But get good quality ones, not cheap "digital" cables you pick up anywhere which might or might not really be 75 ohm, might have 75 ohm BNC connectors or might not, might have very thin/low strand count inner conductors that will break over time, may not be crimped properly or use proper BNC components etc. etc.

[JFreak]

Originally Posted by Darryl Ramm

and some spares

This. Don't put yourself into a situation I found myself once

[frazzz]

I tried to order with Blue Jeans but the Paypal payment would not go through - It seems something was missing at the Blue Jeans side - They accept credit cards over the phone - I'll see about this.

I've seen Beldon 1694A on Amazon - Is there much difference between 1694A & 1505F? - Thanks