Film-Tech Forum ARCHIVE: HD-SDI terminations

This is topic HD-SDI terminations in forum Digital Cinema Forum at Film-Tech Forum ARCHIVE.

To visit this topic, use this URL:
https://ft-forum.com/ft/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=16;t=000623

Posted by Chase Taylor (Member # 778) on 08-09-2010, 02:08 PM:

What does everyone use to terminate there HD-SDI cables with? I've used some Bomar 678-KCC1694BQ that was just badly designed connector. I switched to ICM Corp FS6BNCU-R with some luck now I've had some trouble with those.

Does anybody have any recommendations?

Chase

Posted by Steve Guttag (Member # 268) on 08-09-2010, 05:26 PM:

It depends on the cable you use...a VERY BIG key is to match the cable and connector. If using Belden 1694A, we use AMP or Kings connectors.

Posted by Mark Ogden (Member # 43) on 08-09-2010, 06:34 PM:

For one thing, I recommend NOT using a compression-style connector, as the two you mentioned are. I don't know if you are doing permanent block point style wiring, or if you are often making and breaking these connections at a device, but I've never seen one hold up over the long haul. Invest in a good crimping tool, and use the connectors Steve mentioned, or any other ones that require you to crimp the center pin right onto the cable center conductor, and then the jacket sleeve to the outer shield. Make double sure that the strip depths and lengths are accurate for the connector you are using, or the whole thing will fall apart pronto.

Kings are pretty much the broadcast standard, for what it's worth.

Posted by Bruce Hansen (Member # 281) on 08-09-2010, 08:36 PM:

Make sure that you use 75 ohm connectors. With composite video, the wavelengths are long enough that using a 50 ohm connector worked fine; but HD-SDI runs at 1.5 Gigs. The much shorter wave lengths don't like those old 50 ohm connectors. As above, use crimp on connectors; don't ever use screw on connectors, they are pure CRAP. When crimping the center pin, it should sit right down on top of the center conductor insulation. This keeps the impedance correct. Use the proper crimp tool for the connectors you are using. A properly crimped connector will be VERY hard to pull off the cable.

Posted by Chase Taylor (Member # 778) on 08-10-2010, 08:49 AM:

Thanks for the reply.

I've always used AMP for my DB25 connections, but with my attempt to make my HD-SDI cables look as nice as I could I went with the compression connectors, that was a mistake.

I will take a look at AMP and King, I'm using 1694A do you have a part number to save me the time of digging to the end of the world to find. Tyco/AMP does not make this easy.

Thanks Again

Chase

Posted by Scott Norwood (Member # 30) on 08-10-2010, 08:51 AM:

Call Markertek. They have pretty much every type of cable and connector that you could possibly need (both video and audio). The people who answer the phones actually know about the products that they sell, too.

Posted by Bruce Hansen (Member # 281) on 08-10-2010, 05:42 PM:

IMO, 1694A is good for long runs (+250 feet), but it is stiff, heavy, and expensive. For shorter runs you can use 1505A, which is a RG-59 like SDI/HDSDI cable. For short runs use 1855A. It is smaller, more flexible, and lighter. Beldon says 1855A, in new condition, will do 210 feet with HDSDI. I would not push it, though. When wireing patch panels, or DAs, where there are a LOT of cables, and usually short runs, 1855A is a lot easier to work with. Using 1694A, the rack would be so crammed with cable, you could not get to the back of the equipment. In a truck, where weight is a consideration, 1855A is lighter. There is also a HDSDI version of RG179 (the real tiny stuff).