Premium Members brett.mayfield Posted December 12, 2013 Premium Members Report Share Posted December 12, 2013 hey yall i was handed a teradek bolt to try for today on set and i have a questions regarding the receiver and power sources. the package contents contain 2x ptap to lemo, suggesting to me that a cable would go to each the transmitter and receiver. the transmitter worked fine with the cable and patp power. i had the receiver screwed atop a smallhd ac7, which was powered by an anton bauer dionic 90 and hytron 140 for testing. the monitor received power normally but when i plugged the teradek receiver in via ptap to lemo, the monitor shut off and the battery meter flashed. i tried this with a vmount adapter and battery (not connected to the monitor) with the same result. when the receiver is plug into dc power it works fine. the teradek bolt power input reads 6-28v i am still behind on my eletrical knowledge. why would none of the batteries power the bolt? im sure this is somethin as simple as "it draws too many volts," but why does the the input show 6-28v? have a good one. brett. Quote Link to comment Share on other sites More sharing options...
Premium Members Tom Wills Posted December 12, 2013 Premium Members Report Share Posted December 12, 2013 The flashing display means the AB is either being overdrawn (which is pretty much impossible in this situation, since you're just powering a bolt and a monitor), or the battery is being shorted. That seems to be likely. It turns out that there are 2 standards for 2 pin LEMO power connector pinouts in our industry. The Bartech, any devices with that same pinout, and I believe all small Steadicam rigs pre-Zephyr were all wired with pin 1 of the LEMO being hot, whereas the Bolt and almost everything else that uses a 2 pin LEMO has pin 1 as ground. That means that Bartech and Bolt LEMO cables, while identical from the outside, are backwards, and can absolutely smoke gear if you're not careful. (I have, and it's not pretty. Safe to say, all my cables for both devices are now clearly labeled) If the Bolt receiver were powered with a backwards cable, it's possible that the positive voltage line could be on the shell of the BNCs, and when that hits the grounded shell of the monitor BNC, it shorts out the battery and the battery shuts itself down. Pull the cable you're using on the receiver from the kit and have someone test it for polarity. If pin 1 in the LEMO is power and not ground, that's the culprit. Quote Link to comment Share on other sites More sharing options...
Premium Members Victor Lazaro Posted December 12, 2013 Premium Members Report Share Posted December 12, 2013 Yep. Try to swap those two p-tap cables see if it's cable related. I had that experience as well with a bartech and a bolt. Be careful and always carry a volt meter with you to check polarities. 1 Quote Link to comment Share on other sites More sharing options...
Premium Members Robert Starling SOC Posted December 12, 2013 Premium Members Report Share Posted December 12, 2013 If memory serves me correctly one of the factory cables we had from Bolt was wired reverse polarity. Once we sorted that out it worked fine. If you have access to a multimeter you can test the cables. If you don't have a multimeter in your kit then get a little portable one from Radio Shack for $14.95 and keep it in your kit to check voltage and continuity. Good luck, Robert Quote Link to comment Share on other sites More sharing options...
Premium Members Jess Haas SOC Posted December 13, 2013 Premium Members Report Share Posted December 13, 2013 Anyone know if the bolt and bartech and protected from reverse polarity? Love to know if hooking up the wrong cable has the potential to let out the magic smoke. Contemplating rewiring my bartech and cables so I can just have one set of cables.... Quote Link to comment Share on other sites More sharing options...
Premium Members Jarrett P. Morgan Posted December 13, 2013 Premium Members Report Share Posted December 13, 2013 The bolt should be protected against reverse polarity (as should the MDR3, it is the same connector and pin out as the bolt and Alexa). The bartech is absolutely not. It will smoke and go NFG. Thankfully apparently it is a cheap part for Jim to fix, but still not very convient. Quote Link to comment Share on other sites More sharing options...
Premium Members Brian Freesh Posted December 13, 2013 Premium Members Report Share Posted December 13, 2013 It's so cheap to fix because the part that smokes is there to protect the rest of the BFD. It's more of a fuse than a circuit breaker is all. Def not as convenient, but a cheap fix. Quote Link to comment Share on other sites More sharing options...
Premium Members brett.mayfield Posted December 13, 2013 Author Premium Members Report Share Posted December 13, 2013 Thanks for the info, yall. Ill definitely be picking up a multimeter. since the bartech and the teradek are both wired with reverse polarity, so this would suggest that the cables included with the teradek (i dont know about bartech) are also reverse, which is why we wouldnt want to use them with other accessories correct? nor non-reverse cables with either of the devices either...? Quote Link to comment Share on other sites More sharing options...
Premium Members Alan Rencher Posted December 15, 2013 Premium Members Report Share Posted December 15, 2013 The Bartech is not wired reverse polarity. The Bolt is ground to pin one (Arri style), and the Bartech is ground to pin two. The digital Bartech is reverse polarity protected. I'm not sure about the analog Bartech or the bolt being reverse polarity protected. Quote Link to comment Share on other sites More sharing options...
Javier Santos Posted September 5, 2016 Report Share Posted September 5, 2016 So in that case, is it possible to change the polarity on a 2 pin lemo to Dtap cable? From Teradek compatible to Bartech compatible? Since it's probably the easiest to access, could it be done by changing around the Dtap wiring? Or do you need to open the Lemo and rewire it? Cheers Quote Link to comment Share on other sites More sharing options...
Premium Members Victor Lazaro Posted September 6, 2016 Premium Members Report Share Posted September 6, 2016 So in that case, is it possible to change the polarity on a 2 pin lemo to Dtap cable? From Teradek compatible to Bartech compatible? Since it's probably the easiest to access, could it be done by changing around the Dtap wiring? Or do you need to open the Lemo and rewire it? Cheers Here is a trick that Alan has to switch polarity. /!\ Be careful to keep track of the polarity of your cable after doing so. You will fry your gear if you make a mistake!!!!!! /!\ https://youtu.be/qXB11DAZh2E You can use his polarity tester to make sure you did it right. https://mediablackout.net/products/2-pin-lemo-polarity-tester Quote Link to comment Share on other sites More sharing options...
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