greg sextro Posted September 28, 2014 Report Share Posted September 28, 2014 Recently had a couple MC 41 cables go bad - or at least I'm pretty sure that's the problem. It sounds (or one would probably think) like power supplies (Denecke) going bad, but swapping them out with PSC models have not helped. Checked for any other week links in the chain. Basically we are hearing intermittent "thumps" and indeed it seems that when we jiggle the TA5 and XLR connectors that we can best re-create the sound. Anyone come across this? Using SM transmitters. Cables made by one of the usual suspects. -Greg- Quote Link to comment Share on other sites More sharing options...
studiomprd Posted September 28, 2014 Report Share Posted September 28, 2014 Gregg: " Anyone come across this? " could be, but what is the difference..? basic troubleshooting: did the cable(s) work before ? same issue with other TX's ?? contact the usual suspect in question. Quote Link to comment Share on other sites More sharing options...
Solid Goldberger Posted September 28, 2014 Report Share Posted September 28, 2014 I know this thumping sound, and it is incredibly frustrating to figure out! I also have experienced it with sanken lavs, so I don't think its likely to be the MC41, but probably a transmitter problem. Have you tried swapping batteries? For some reason that seems to fix these little weird lectro problems for me a lot of the time. I'm hoping that maybe Larry will chime in, as this is one of those things that has happened from time to time that I've never been able to get to the bottom of. e. Quote Link to comment Share on other sites More sharing options...
greg sextro Posted September 28, 2014 Author Report Share Posted September 28, 2014 We've been using rechargeable Imedions in SMQVs. Maybe the batts need refreshing? suppose we should try Lithiums just because. Quote Link to comment Share on other sites More sharing options...
Abe Dolinger Posted October 1, 2014 Report Share Posted October 1, 2014 I've gotten those from bad TA5 connections on lavs! I'd guess the solder's going bad on the connector. Truly an awful sound and feeling. Quote Link to comment Share on other sites More sharing options...
greg sextro Posted October 1, 2014 Author Report Share Posted October 1, 2014 So, get this: after more trouble shooting, we've actually determined that what is likely causing our problem is the walkie talkies on set! When near a "cue-ing" unit, we hear the pops. I was on the phone with lectro and denecke today. Neither had any explanation. Tomorrow we need to try new frequencies on our end, and/or convince production to get the walkies retuned, or that the DP needs to not call commands to our Camera Operators during the take. What still is confusing us is that the problem has seemed to only pop up within the last couple weeks even though we've been shooting since the beginning of August... Quote Link to comment Share on other sites More sharing options...
Jack Norflus Posted October 1, 2014 Report Share Posted October 1, 2014 Is the problem location specific? Quote Link to comment Share on other sites More sharing options...
Eric Lamontagne Posted October 1, 2014 Report Share Posted October 1, 2014 RF build up on the cable between the power supply and the transmitter. Try a capacitor between audio and ground in the TA5. Good Luck Eric Quote Link to comment Share on other sites More sharing options...
LarryF Posted October 1, 2014 Report Share Posted October 1, 2014 Hi Greg, Sorry to come in late but I didn't flash on the MC41. I was thinking of an old Shure portable mixer. Try turning the gain down on the SM and turning it up on the driving device. That is a possible quick solution. Best would be to try connecting the strain relief clamp of the TA5 to the shield of the cable. Right now all 4 fingers (2 pairs) of the strain relief clamp the insulator. We may need to change the way we ground to the shield by having two fingers clamping the insulation and two fingers clamping the shield. Try the shield-fingers fix first and let me know if that solves the problem. Best Regards, Larry Fisher Lectrosonics Quote Link to comment Share on other sites More sharing options...
LarryF Posted October 1, 2014 Report Share Posted October 1, 2014 Hi Greg, Sorry to come in late but I didn't flash on the MC41. I was thinking of an old Shure portable mixer. Try turning the gain down on the SM and turning it up on the driving device. That is a possible quick solution. Best would be to try connecting the strain relief clamp of the TA5 to the shield of the cable. Right now all 4 fingers (2 pairs) of the strain relief clamp the insulator. We may need to change the way we ground to the shield by having two fingers clamping the insulation and two fingers clamping the shield. Try the shield-fingers fix first and let me know if that solves the problem. Best Regards, Larry Fisher Lectrosonics You can keep the pin 1 connection as it is to the shield. The fingers will be in addition to pin 1. Thanks, LEF Quote Link to comment Share on other sites More sharing options...
greg sextro Posted October 1, 2014 Author Report Share Posted October 1, 2014 Thanks for the input guys. I will have to check the new cables we had made from Pro Sound. This time I had them include the EMC connectors on the XLR end. We generally run the gain on the transmitters at about 23-25. I bought in a plug on UH400 and though the problem was less noticeable, it was still there. (granted, during that test we were cueing a walkie right next to the transmitter...) We have encountered the problem on the various stages we shoot at Silvercup - but also when we shoot outside on location. Quote Link to comment Share on other sites More sharing options...
LarryF Posted October 17, 2014 Report Share Posted October 17, 2014 You can keep the pin 1 connection as it is to the shield. The fingers will be in addition to pin 1. Thanks, LEF Hi Greg, Any update on this? Best Regards, Larry Fisher Lectrosonics Quote Link to comment Share on other sites More sharing options...
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