Glad to be a part of this forum. I'm new to Steadicam and have been practicing with my Flyer for a couple months now. I use a GH4, to an Atomos H2S, to a Decimator 2 from which I have to drop the power line down to the batteries on my bottom stage. The reason for this is that when I first purchased a Decimator, I had a lemo to 4x P Tap port/splitter from Alvin's cables that I thought would come in handy in the future. Plugging that into my top stage, and then the Decimator into one of the 4 ports via DC to P Tap, i shorted the Decimator. Smoke poured, and examining the inside of the Decimator I can tell I burnt it pretty bad. So I thought for sure, that splitter must have been the problem, maybe it was the polarity. Luckily I had bought that one second hand and just bought another one new, along with the Nebtek DC to lemo from B&H made for the Decimator. Problem is, when I plugged my new Decimator into the top stage of my Flyer with this Nebtek cable, I heard a pop again and quickly unplugged the cable. Very slight smell of smoke again but I managed to save my Decimator and have been using it with no problem. For learning and practicing I don't have too much of a problem dropping that power cable, but at this point I am afraid the issue lies with my actual Steadicam and the lemo power port. I'm hesitant to plug anything else into that port until I can figure out what the issue is, and hoping someone on here can point me in the right direction. It is worth noting that I also bought the Flyer secondhand from someone on Craigslist and haven't been able to verify with them if they had any issues with the rig.
Thanks in advance for any replies!
Edited by Nick Billiris, 09 January 2018 - 07:45 PM.
What you've described is a common issue - there are 2 different polarities of 2 pin LEMO connector. One of them, used by ARRI, RED, Teradek, SmallHD, and many others (called the ARRI standard), has pin 1 as ground, and pin 2 as +12v. The other, which has existed for a longer time, is the "Bartech" standard, used by Bartech, Cinema Products (the former maker of Steadicam, who invented this standard), Tiffen, Hocus Products (maker of the Axis 1), RedRock Micro, and many others. The Bartech standard uses pin 1 for +12v and pin 2 for ground.
All that is a bit more information than you need, most likely, but it is really just a long way of saying that your Steadicam uses a 2 pin LEMO that is reverse polarity from almost all of the commercially available 2 pin LEMO cables available on the web. Any cinema custom cable provider could certainly make you one with the right polarity, and most of them (MediaBlackout, EastCoastCables, etc...) would ask you which polarity you needed when ordering. Check here for more information: https://mediablackou...pin-Lemo-cable-
Future rigs eliminated the 2 pin LEMO, replacing it with a 3 pin (which only has one standard polarity, thankfully), but for you, right now, you should desolder and flip the polarity of the LEMO to D-Tap splitters you have, and any other cables you bought for the rig that are reverse polarity. (Any cables that came from Tiffen, like a 4 pin XLR cable, should be the correct polarity) In addition, I highly advise you to label all of your cables with warnings about their polarity. Nothing feels worse than an assistant plugging in one of your cables to the wrong port and blowing up a camera. The same goes for Bartech (or other focus unit) cables. All of my Bartech cables have red ends, and have big warning labels on both ends and on the cable, so that someone would have to be willfully ignorant to use that cable on a Teradek (and by doing so blow up the camera, monitor, or whatever else they were using it on).
If you're not up on soldering yet, it is possible that you can flip the cable's polarity by spinning the outside shell of the LEMO, but this is not advisable to do on a long-term basis, as it will mean that the cable will appear to have one polarity, when it in fact has the other. To do this (which, again, I'd only do in a pinch, and change back as soon as possible), you push the LEMO shell back, like you're trying to remove it from a socket, and then while pushing it back, rotate the shell 180 degrees, until it clicks back into place upside down. Again, this is a last resort, and I take no responsibility for anyone who does this and then blows something up, but in a pinch, it could work.
I hope this helps! Feel free to reach out if you have any more questions!
Thank you for your helpful reply. Over the last month I've been doing some practice with a Black Magic Ursa Mini Pro and have been making out fine powering anything I need off that camera's V-Mount battery. I'm wondering if you can point me in any direction in regards to desoldering the LEMO to D-Tap splitter I have. I've done some soldering in the past but certainly want to make sure I do this correctly.
The other thing I'd like to ask about is upgrading my rig to HD-SDI. Unfortunately, I ran into another problem recently where the SDI out on my friend's Ursa Mini Pro seems to have shorted the SDI on the top stage of my rig. Apparently, the grounding on those cameras can be done poorly and is a common problem. Something about unplugging the SDI while the camera is powering up. He unfortunately has to send it in for servicing, but luckily we've still been able to practice using the front SDI on his camera and dropping a line down to another monitor. My Flyer monitor seems fine, as well as my decimator, so I assume that this is what happened. The thing is that I have had enough minor headaches since getting this rig, which all have been related to using this composite monitor, so I'm thinking that just upgrading my rig to HD-SDI will certainly be worth it, and I can just pick up another monitor. I've seen a few posts on this forum explaining the how-to, but I'm open to any advice you have to offer, as well as if you know anyone able to do this in the Philly area.
Just an update, the Decimator seems to be the problem again, as I tested my rig with a different composite signal. With that said, still looking for advice on soldering that power cable and resources for upgrading my rig. Thanks again.