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Slinky thin BNC?


Dan Coplan

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I'm working a 2-week long shoot. Sure enough, the one day the executive producer decides to show up, my transmitter decides to act up and it's hardwired I went. Not prepared for this, I ran with BNC cable that could better be described as semi-flexible metal tubing.

 

Any recommendations where to get super slinky RELIABLE BNC that I can run either all the way to the monitor or at least to the back of my vest where I can barrell connect to another BNC?

 

Dan "Living and Learning" Coplan

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Dan,

 

Try BTX (formerly called Bitronics) at 800-666-0996 (www.btx.com). They sell a Mogamni cable that is crazy thin and flexible.

 

http://www.btx.com/ItemForm.aspx?item=WV-2...d9-45614e023cb5

 

The above link is just the cable, but you'll need a special crimp tool to make them because it is so thin. I just order them pre-maid. To do this, order "YV-BB2381_" The "_" represents the last digit, which specifies the length you want. For example a three foot cable would be "YV-BB23813."

 

I'd definitely order them as jumper cables to the vest as you will ruin it very fast if you try running it to a monitor. Also, in short lengths (I've used up to six feet - I have 3,4 & 6 footers) you can use them with HD-SDI without breakup (despite the fact they are rated at 50 ohms).

 

Cheers,

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Gents--

 

You can order Belden 9221 from several outfits like Newark Electronics. Total overall diameter is 0.10" and is capable of working with HD-SDI since it is 75 ohm cable. We need to use 75 ohm cable for many reasons.

 

They (Newark) also carry the Pomona BNC connectors that fit cable group RG-174, -179 which covers Belden 9221. There are also several crimp tools to work with these items.

 

I have used Belden 9221 cables, built up by myself, for over fifteen years now without any problems. This cable has also proven itself with TriAx to CoAx adapters as well.

 

Just my .02

 

Best,

 

Brant S. Fagan, SOC

Steadicam/Camera Operator

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Brant,

 

I have some of this too and use it for Triex because I think it is safer when passing voltage through it. For other uses, I think the Mogami is better. Thinner and more flexible. It is fine for SDI viewing (I should have stated I wouldn't use it for recording - although I bet it would actually work fine, but I don't want to be the one making that call). I have used it on a lot of HD shows and the engineer has been fine with it (don't tell him its 50 ohms because then he'll say "no" without looking - tell him you are using a jumper and then put it in and you'll find its fine). Yes, we need 75 ohm for lots of reasons when we are splitting the image up, etc (thus I bought all the 75 ohm), but when we are not transmitting (in Dan's case) or when we are transmitting from a Downconverter (then we have our usual 75 ohm BNC into the sled in addition to the HD SDI out), no problems. This cable is invisible (until you walk away without untethering because you forgot about it).

 

I guess I suggest, buy both; choices are a good thing.

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I agree with Alec that owning both the 75 ohm, and the thinner 50 ohm is a good idea. I route HD-SDI to the downconverter using the heavier cable, then usually off the sled with a 6' ultra thin 50 ohm cable. The DP's will love you for giving them an HD monitor to look at while shooting. Also, if you give them HD most of the time, it's easier to sell them on wireless when you really need to be cable free. As long as they know they'll be looking at the HD monitor the majority of the time, they're cool with it. Of course, this is for a monitoring signal only.

 

Fred Davis at PCS also makes both kinds of BNC jumpers, with his usual quality. I know many ops take pride in making their own cables, but if you're inclined to just buy them, Fred is another great source at 626-794-1534.

 

Mark Karavite

A Camera / Steadicam Operator

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I agree with Alec that owning both the 75 ohm, and the thinner 50 ohm is a good idea. I route HD-SDI to the downconverter using the heavier cable, then usually off the sled with a 6' ultra thin 50 ohm cable. The DP's will love you for giving them an HD monitor to look at while shooting. Also, if you give them HD most of the time, it's easier to sell them on wireless when you really need to be cable free. As long as they know they'll be looking at the HD monitor the majority of the time, they're cool with it. Of course, this is for a monitoring signal only.

 

 

That doesn't work on Viper Shows.... We HAVE to cable out the HD-SDI link.

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I'm a big fan of the Mugami 2964 HD CoAx cable. Plenty of copper down the middle ( after all, we are running 165 volts down there... ) and- the big selling point for me- a neoprene jacketing. Visually it may be thicker than some other cables, but I used it for 20 years doing tri ax to co ax jobs, as well as using it for off-rig hardwire situations like the one faced by our OP'er and nary an issue.

 

Bi-Tronics and Markertek both sell it. I own a crimper- DONT buy the crimp tool. I'll be glad to loan it around.

 

Even in bitter cold, the neoprene jacketing does not stiffen up as badly as vinyl.

 

My two cents.

 

Peter Abraham

New York

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Guys;

 

I have to say I used the thin stuff for a really long time but after the ends kept being pulled off and I got tired of replacing them I just went with the standard BNC cables. (I also got to the point in life where disposable income goes toward retirement.)

 

I now just use short BNCs off the shelf for $5-9. for the short runs and the regular stuff for everything else.

 

Except for some occassional really stiff long cables, they're all pretty darn flexible these days.

 

I carry acouple of 25' cables that are flexible enough ($25.00). Mostly I transmit anyway.

 

Ok, everyone says weight issues, my short "regular" BNCs are probably 6-10 oz. and your thin ones

are 4-6 oz. Not a big deal to me.

 

Just my opinion (but you may want some of that money back some day and it does add up).

 

Janice

(my two cents)

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I have to say I used the thin stuff for a really long time but after the ends kept being pulled off

 

I can stand by this, I use the thin RG58 stuff for a jumper between camera and vest, when I need to be cabled. I had to do a music concert over the weekend on a BNC, and used a thin cable, and the feed to the vision mixer was suddenly lost as the cable decided to part company with the connector, which stayed on the camera body. As far as I am aware, there was no pull or tug on the cable and I had it secured in the usual way, but even so, the strain relief boots on the cable were absolutly useless and did nothing to stop this happening.

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As far as I am aware, there was no pull or tug on the cable and I had it secured in the usual way, but even so, the strain relief boots on the cable were absolutly useless and did nothing to stop this happening.

 

Sounds more like a problem with that specific cable (or batch of cables). If made properly, they should definitely not come detatched under their own weight. Obviously, they need to be treated with a little more care than their full size counterparts. They will usually lose the battle if they're stepped on or tugged firmly, but other than that, if they're handled properly, they should last quite a while.

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