Film-Tech Forum ARCHIVE: Making RG-6 Cables (BNC)

This is topic Making RG-6 Cables (BNC) in forum Film-Yak at Film-Tech Forum ARCHIVE.

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Posted by Manny Knowles (Member # 1171) on 02-17-2012, 07:15 AM:

Would anyone care to share their experiences (pros and cons) working with compression versus crimp connectors?

Posted by Steve Guttag (Member # 268) on 02-17-2012, 08:44 AM:

Without a doubt, conventional crimps have proven to be more reliable than compression and we have definitely tried both.

A key to ANY crimp is to ensure that you have the proper crimps and crimper for the cable you are working with. Merely having RG6 in the spec is not sufficient!

We have had to remake cables that "others" installed using compression crimps where the cables fell out of the connectors. We then noted that the installer, despite using the same brand cable for both cables (different colors)...the OD of the cables were not the same.

I have found that cheap cables and crimps just bite one in the butt, eventually.

The only compression crimps that have been sufficiently reliable for us have been the RCA and "F" connector variety. For BNCs though...stick with the conventional crimp!

Note, there is more to a crimp that just the connector and crimper...the cable MUST be prepared correctly too.

Posted by Richard Hamilton (Member # 321) on 02-17-2012, 08:46 AM:

Manny,
I've only made a few cables and they were on-site. I had to buy a stripper (not the naked kind, for the coax) and screw on the connectors. Wow, I said stripper and screw in a sentence twice now. I didn't want to pay the $50 for a set of dies for my crimper. I can't give any advice because my limited experience. What I can say is, I never had any problems with those racks. (he he, I got "racks" in there too)
Rick

Posted by Mark Ogden (Member # 43) on 02-17-2012, 10:40 AM:

If you are just going to put the connector on the cable and install it on a piece of terminal equipment or an output of a VTR or somesuch thing in a low traffic area, and then just leave it, then possibly you could get away with a compression/screw on type connector with appropriate strain relief.

If you are going to be making and breaking the connection after it is installed, or it is going to be in an area with any physical traffic at all, you are much better off going with a crimp connector. Compression connectors suffer from very low pull strength ratings, 75 - 90 lbs typically, which amounts to little more than a footfall from your average Teamster. Crimp connectors are stronger PROVIDED that the cable was stripped to spec, paying special attention to the height of the center conductor and the amount of the outer jacket left for the sleeve to grab onto. If you see yourself making a bunch of these, a good investment is a Kings or Belden or Canare stripper with the correct blade block for the cable you are using.

Posted by Manny Knowles (Member # 1171) on 02-17-2012, 10:09 PM:

Thanks for all the comments. To clarify - these cables will be for temporary duty applications - they'll have to be durable. I'm already convinced to go with the crimp-type.

Posted by Bruce Hansen (Member # 281) on 02-19-2012, 07:06 PM:

Crimp ons are best. Compression connectors are not very good, screw ons are bad. I don't think you can even get a screw on in 75 ohm.

Posted by David Buckley (Member # 2600) on 02-19-2012, 07:35 PM:

quote: Steve Guttag
you have the proper crimps and crimper for the cable

There's no overstating how important that fact is. The wrong match leads to an unreliable connection.

Do this lark for a few years and you end up with a boxload of crimping tools. Trouble is, they all look pretty much the same, so my contribution is when you buy your first expensive crimping tool, get a cheap engraving tool at the same time, and engrave onto the crimper exactly what cable and crimps it fits.

Wish I'd thought of that when I started out...

Posted by Steve Guttag (Member # 268) on 02-19-2012, 10:44 PM:

We have a separate "kit" for each type of cable we support. For instance, our "RG-6" kit is only for Beldend 1694A and 1695A cable...that is it...the kit has the crimper and crimps. Likewise, we have a WPW818 kit and on down the line...it limits what cable we use. If we are going to support another cable...it has to bring something to the mix because we are going to have to get another crimper/dies and crimps to support it. That can get to be expensive!

Posted by Manny Knowles (Member # 1171) on 02-20-2012, 01:03 AM:

Yes, I plan to stick with the cable stocks used in our system. I've noted the stock and tracked down the appropriate crimps. The matching crimp tools and dies I've seen aren't cheap, so it gave me reason for pause. But I think I've been sufficiently reassured to go with crimping the connectors -- thanks to all of your comments.

Posted by Bruce Hansen (Member # 281) on 02-21-2012, 08:06 PM:

BTW, 1694A (RG-6) is big, heavy, and stiff. That makes it hard to work with. 1694A does not give you much of an advanage over 1505A, and 1505A is easier to work with. For short runs 1855A is smaller, and lighter. When working on a rack of DAs or patch pannels, if you use 1694A you will not be able to get to the back of the equipment, the rack will be so packed with cable. Beldon says that HD SDI, at 1.5G will go 200 feet down 1855A.

Posted by Steve Guttag (Member # 268) on 02-21-2012, 09:19 PM:

For a picture of a rack of patch bays wired with 1695A (plenum version of 1694A)...in the picture warehouse of this forum (AFI/Silver)

http://www.film-tech.com/warehouse/pics/afi/AFISPicture82.jpg

It is servicable but as Bruce says...it is big heavy stuff and one has to know how to dress it.

A lot of people use 1505A. If were in the broadcast market, we would definitely work with smaller options...however, for what we do and in the DCinema industry, 1694A works well and since it is normally just a pair of cables...it is actually easy to work with because it is stiff/heavy. Easy to strip, easy to crimp...works every time.

Posted by Manny Knowles (Member # 1171) on 02-21-2012, 11:02 PM:

I've got quite a bit of Gepco VSD2001 in various colors.