audiofp Posted March 10, 2014 Report Share Posted March 10, 2014 My M216 lives in my bag 100% of the time and I'd like to power it with the BDS. Comtek tech support basically came up with the same idea as me: Fashion a wood block to 9v battery dimensions, mount the appropriate terminals/wire and power it with a regulated 9v feed from the BDS. I've looked at the ISO9VOLT but the connector is in the wrong place. Before I put this together has anyone come up with another solution? -Thanks Quote Link to comment Share on other sites More sharing options...
RPSharman Posted March 10, 2014 Report Share Posted March 10, 2014 A 9v battery lasts all day, or at the very least 1/2 day, and requires no additional space or cabling. Why add more stuff to your BDS and more cables to your bag? Quote Link to comment Share on other sites More sharing options...
ProSound Posted March 10, 2014 Report Share Posted March 10, 2014 An Ipower rechargeable 9V will last 16+ hours in a Comtek TX Quote Link to comment Share on other sites More sharing options...
audiofp Posted March 10, 2014 Author Report Share Posted March 10, 2014 Thanks. I'm currently using iPower 9vs. You both make a good argument but the OCD side of me wants everything in the bag on BDS. One switch and it all turns off. It's one 9v I won't have to chase down the night before. Quote Link to comment Share on other sites More sharing options...
RadoStefanov Posted March 10, 2014 Report Share Posted March 10, 2014 I use to have lectro 9v battery eliminator and it works well... But now I use Ipower rechargeable. Works 2 days... Quote Link to comment Share on other sites More sharing options...
Matt Radlauer Posted March 10, 2014 Report Share Posted March 10, 2014 +1 for Ipowers. More wires..more chance for a bad wire to cause you a headache when you need it the least. Quote Link to comment Share on other sites More sharing options...
ProSound Posted March 10, 2014 Report Share Posted March 10, 2014 If you really want to power it from BDS then get the Comtek BST 75-216 http://comtek.com/bst-75-216/ I use this on my cart and also in my 664 bag provides a much stronger and better quality transmission. I use the 9v powered TX in my 633 bag I am already charging Np-1 AA Sony L mounts and I power 9v for the comtek RX so charging one more battery is no big deal. Quote Link to comment Share on other sites More sharing options...
Dennis Haggerty Posted March 10, 2014 Report Share Posted March 10, 2014 I use a battery eliminator, I got it from Location Sound in LA back in 2004. Can't remember what it cost but it has been very convenient for me. One power switch for the whole bag etc. Having another plug into my BDS is no big deal for me. Seems like infinitely less hassle than charging another battery every couple days. Best, Dennis edit - one hassle was I had to drill a hole in the batt door for the cable, took 10 min 10 years ago. no biggie. Quote Link to comment Share on other sites More sharing options...
audiofp Posted March 10, 2014 Author Report Share Posted March 10, 2014 If you really want to power it from BDS then get the Comtek BST 75-216 http://comtek.com/bst-75-216/ 10mw vs 100mw. Notice any add'l rf problems in the bag from that? Thanks Quote Link to comment Share on other sites More sharing options...
Wyatt Tuzo Posted March 10, 2014 Report Share Posted March 10, 2014 I forget who it was (maybe Eric Toline?), but a while back I got the recommendation for this eliminator from either this board or RAMPS, and it's worked flawlessly for years. I just snipped off the wall wart, and added my DC connect of choice. http://www.qcavionix.com/be-9.php?cat=20503 I had to file a small cable exit in the battery door, but it didn't require too much surgery Quote Link to comment Share on other sites More sharing options...
audiofp Posted March 10, 2014 Author Report Share Posted March 10, 2014 I like that- Thanks Wyatt Quote Link to comment Share on other sites More sharing options...
RPSharman Posted March 10, 2014 Report Share Posted March 10, 2014 10mw vs 100mw. Notice any add'l rf problems in the bag from that? Thanks The BST has variable output if you get into any trouble. But 216 is far enough away from radio mics, that it should be ok. Quote Link to comment Share on other sites More sharing options...
Scott Smith Posted March 10, 2014 Report Share Posted March 10, 2014 One other possible issue is RF current getting reflected back through the power connection into the BDS. I don't think there are any isolation chokes in either the BDS ver 1 or 2. Also, I don't know if negative battery ground ts at the same potential as the sleeve on the micro-jack input (Comtek doesn't make schematics available for their current products). Might be creating more grief than it's worth... --S Quote Link to comment Share on other sites More sharing options...
audiofp Posted March 10, 2014 Author Report Share Posted March 10, 2014 The BST has variable output if you get into any trouble. But 216 is far enough away from radio mics, that it should be ok. Trying to keep my bag light for this tired old body. The BST adds another 11 oz. One of the reasons I shifted to 633/Stingray. I'll probably go with the 216/BDS experiment for now. One other possible issue is RF current getting reflected back through the power connection into the BDS. The Comtek tech had thoughts on that. We'll see. Quote Link to comment Share on other sites More sharing options...
Wyatt Tuzo Posted March 10, 2014 Report Share Posted March 10, 2014 I don't have mine wired to a bds, but have it wired to an output on the MEON. Just to be safe, I added a ferrite choke. Not saying that issues are not possible (or even likely), just that in my experience, I haven't had any. Quote Link to comment Share on other sites More sharing options...
RPSharman Posted March 10, 2014 Report Share Posted March 10, 2014 I'll second the ferrite collar suggestion. Almost all RFI/power issues for me have traced back to Comtek. They are a great company with great products, but their designed application (originally) did not require the same sort of power issue considerations we need for our application. Quote Link to comment Share on other sites More sharing options...
audiofp Posted March 10, 2014 Author Report Share Posted March 10, 2014 I ordered a choke with a switchcraft 761k connector. Damn- a lot of help here! Thanks! Quote Link to comment Share on other sites More sharing options...
Daniel McIntosh Posted March 11, 2014 Report Share Posted March 11, 2014 (edited) I do not have this cable, but this PDF was sent to me from Comtek some time ago: AP-216-12-XLR3F_Audio_Power_Cord.pdf It powers the M-216 Op 7 via the mini input. The diagram does appear to show a ferrite collar. Edited March 11, 2014 by Daniel McIntosh Quote Link to comment Share on other sites More sharing options...
audiofp Posted March 11, 2014 Author Report Share Posted March 11, 2014 Looks like a choke near the transmitter connector. I don't find this cable or details anywhere. The tech I talked to didn't mention it. Quote Link to comment Share on other sites More sharing options...
PelicanSound Posted March 12, 2014 Report Share Posted March 12, 2014 on my m-72 I soldered wires to the battery terminal for my BDS in case i have to run on batteries for the comtek and not use my BDS power. Quote Link to comment Share on other sites More sharing options...
John Blankenship Posted March 12, 2014 Report Share Posted March 12, 2014 I use these for Comtek powering, both on the cart and in a bag: http://www.qcavionix.com/be-9.php?cat=20503 It requires that I file a small rectangular hole for the cable to come through on one side of the Comtek where the door and the housing meet. For use with the M216, I also file the outside of the battery eliminator's case a bit to make it fit well. Quote Link to comment Share on other sites More sharing options...
Scott Smith Posted March 12, 2014 Report Share Posted March 12, 2014 The choke is part of the XLR connector assembly on the input. Newer Comtek input cables have a nice little inline splice box. I have the schematic at the shop. can look it up if needed. However, this does not address any possible RF current flowing through the power connection. It only helps reduce RF from getting back-fed to the audio source. (And even with that, there is still some leakage). --S Quote Link to comment Share on other sites More sharing options...
jlempen Posted March 13, 2014 Report Share Posted March 13, 2014 Hi all! I've used a Dremel to drill a small opening for the DC input into the M-216's battery door right next to the hinge. This allows me to use an old Sennheiser 9V battery eliminator (model DC-1) that was originally intended for use with the first generation Sennheiser Evolution G1 transmitters or receivers. Input voltage is 9V to 18V and it delivers a constant 8V at 200 mA. Works great with the Comtek. Quote Link to comment Share on other sites More sharing options...
audiofp Posted March 13, 2014 Author Report Share Posted March 13, 2014 I went with the QCAvionix Battery Eliminator. Nothing is easy- it's slightly deeper so I'll have to accommodate that. For use with the M216, I also file the outside of the battery eliminator's case a bit to make it fit well. Where did you shave- the back of the eliminator, front or both? Quote Link to comment Share on other sites More sharing options...
Matt Radlauer Posted March 13, 2014 Report Share Posted March 13, 2014 I was sent this schematic a while back when I was trying to rebuild my comtek cable.. It has an exploded view of the choke..as well as the resistors at the connector end. I rebuilt this cable with a ta3 end for my 664 with all the resistors inside the connector.. pain in the ass! I use a ferrite choke at the other end because I didn't want to make any cuts in the cable to make their version of the choke.. So far so good. cable_diagram.pdf Quote Link to comment Share on other sites More sharing options...
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