SDI cable question

[Sam Roberts]

I have never had to use SDI inputs or outputs before now. Is the regular every day BNC cable I've been using for composite and component video interconnects OK for SDI? Any length limits?

 

[Carl Larsen]

AFIK, SDI Requires a 75 ohm bnc cable. You can tell the difference between 75 ohm cable and 50 ohm cable by wether or not there is a plastic sleeve next to the pin in the connector - if it has a plastic sleeve you have a 50 ohm cable.

75 ohm cable will work with starndard 50 ohm equipment, but not the other way around.

As for length limits, I've heard things get unpredictable once you get over 300 feet or so.

 

[Robert Permenter]

For short runs you should be fine. Still it could pose a problem. You really should be using a higher bandwidth cable for anything much longer than 25'. And if I remember correctly RedOne uses HDSDI, which will need an even higher bandwidth. So for jumpers you'll probably be fine with what you have. Anything longer get the correct cable to avoid any issues.

And yeah I forgot about the 300' limit. If you need to go longer than that you need a "Reclocking D/A".

 

[martinnoweck]

AFIK, SDI Requires a 75 ohm bnc cable. You can tell the difference between 75 ohm cable and 50 ohm cable by wether or not there is a plastic sleeve next to the pin in the connector - if it has a plastic sleeve you have a 50 ohm cable.

75 ohm cable will work with starndard 50 ohm equipment, but not the other way around.

As for length limits, I've heard things get unpredictable once you get over 300 feet or so.

afaik analog composite / component video also requires a 75 ohm cable - 50 ohm is / was for antenna and network connections. you will get a signal with wrong luminance using 50 ohm cable for analog video.

regards,
martin

 

[Alexandre Bouchard]

Belden 1505F work great. Standard BNC cable like Canare LV-61S will work under 15-20'.

 

[Robert Permenter]

Belden 1694A is also a good chioce. Rated for HDSDI and down.