jorgeadrados Posted October 27, 2013 Report Share Posted October 27, 2013 Hi guys, I just bought a Sanken CSS-5 stereo mic to use my TRX742 with 5 pins cone from zaxcom and I have like RF or grounding problems with it. I´m using a Rycote suspension with 5 pins conbox and the noise is terrible. If I plug the 742 directly to the CSS-5 and I hold the join between them with my hand the noise is gone. Any thought.. Thanks Quote Link to comment Share on other sites More sharing options...
glenn Posted October 27, 2013 Report Share Posted October 27, 2013 Some mics have RF problems and this is one of them. If you use the TRX742 at the bottom of the pole the problem will go away. We have an RF circuit that we can put in the XLR at the bottom of the MIC that will also help to eliminate the problem with the microphone. Glenn Quote Link to comment Share on other sites More sharing options...
rich Posted October 27, 2013 Report Share Posted October 27, 2013 Glenn, is this circuit something that is quite simple that can be done oneself? if so, could you post details of the circuit. or is it something that must be added inside the mic rather than the XLR? Quote Link to comment Share on other sites More sharing options...
glenn Posted October 27, 2013 Report Share Posted October 27, 2013 We put it in the cable and it is frequency block dependent. We made one for a customer and are waiting for results to see how it works in real life. If it works well we will figure out how to provide it. Glenn Quote Link to comment Share on other sites More sharing options...
rich Posted October 27, 2013 Report Share Posted October 27, 2013 lovely. thank you Glenn. Quote Link to comment Share on other sites More sharing options...
jorgeadrados Posted October 27, 2013 Author Report Share Posted October 27, 2013 thanks Glenn. Looking forward for it... Quote Link to comment Share on other sites More sharing options...
Derek H Posted October 27, 2013 Report Share Posted October 27, 2013 Would the off-the-shelf Neutrik EMC XLR connectors help if used as a jumper between the TRX742 and the mic? Of-course this of no help to the OP as Neutrik only makes a 3-pin version. Quote Link to comment Share on other sites More sharing options...
Wandering Ear Posted October 28, 2013 Report Share Posted October 28, 2013 Glenn, I'm also interested in the rf circuit. I use my 742 on the end of the pole usually, and it's usually enough, but on occasion i still pick up some rf. A short cable jumper on the mic side would be ideal for me. Quote Link to comment Share on other sites More sharing options...
Geoff Maxwell Posted November 4, 2013 Report Share Posted November 4, 2013 Glenn, I've been on the fence about purchasing one of these because of this RF problem. Other than that the unit looks fantastic and addresses many needs not the least of which is powering and transmitting AES42. I really do not want to be dependent upon a cable to solve the problem because cables go bad and cable length requirements vary depending upon configuration. I often use the Ambient QAT and adding a cable to that rig is sort of ridiculous. If the solution is frequency dependent and not mic dependent couldn't you just incorporate the RF solution into the unit itself? I assume this RF would be present in the internal recording as well? I'd really like to get one of these ASAP if we can resolve this issue. Regards, Geoff Maxwell Quote Link to comment Share on other sites More sharing options...
rich Posted November 4, 2013 Report Share Posted November 4, 2013 the rf would be present in the recording because it is getting in to the mic - so it is added before the preamp. are you planning to use the CS5 as well? as different mics are less prone to rf interference from the tx - and as i have found in tracking this down in my setup, some jumper cable is more prone to it too. also, taping the antenna to the boom pole can reduce rf noise a bit as well. but if you are looking to transmit AES42, then you shouldnt have any rf issues. i would think that your biggest issue would be battery life. ive never gotten more than 90 minutes with my super cmit on the 742. a better option is the 942 as that will do 5-6 hours on one battery. Quote Link to comment Share on other sites More sharing options...
soundtrane Posted November 4, 2013 Report Share Posted November 4, 2013 AES42 Microphone: up to 4 hours @ 50 mW (one ZPX) Quote Link to comment Share on other sites More sharing options...
rich Posted November 4, 2013 Report Share Posted November 4, 2013 well it seems to be the case that they've underestimated that one. in my usage of the 942, i have gotten comfortably to lunch, and then comfortably to the end of the day after lunch on 2 batteries. Quote Link to comment Share on other sites More sharing options...
Matthias Richter Posted November 4, 2013 Report Share Posted November 4, 2013 I´m the customer who´s got that filter Glenn mentioned. Zaxcom did quite some testing, even rented a CMIT5U because that´s the one I use and tried to find a solution to eleminate the RFI created by my 742 mounted on top of the pole where I had it for my last shoots before it started to create that noisy RFI. The filter does have an influence on the RFI but it does not get rid of it - at least not with MY gear. I now have ordered a custom made TRX-holder that will clip onto the top segment of the pole but with adjustable distance to the mic itself. Hope to get that by the end of this week and will see how it works. If you thinking of purchasing a 742 - you better accept to mount it on the bottom end of the pole. If you prefer to have it on the top (like most people do over here), be prepared to find a personal solution for your specific combo of mic and 742. It´s a challange to say the least ... Best, Matthias Quote Link to comment Share on other sites More sharing options...
rich Posted November 4, 2013 Report Share Posted November 4, 2013 Hi Matthias. i just finished a job, where for exterior scenes we were using a TRX742 plugged into a Cinela Piano with a CMIT 5U and had no problems with rf. what i have found is that the Cinela mounts have the shell of the XLR connected to pin 1, and breaking that connection stopped rf noise getting in to the mic. when testing, i have plugged the 742 directly in to the CMIT with no ill effect. of course, it may be dependant on transmitter frequency - i am on 608 - 638 MHz and i got my CMIT 2 months ago. though let me know your setup, and if i have similar stuff, will see if i can replicate your issues here. Quote Link to comment Share on other sites More sharing options...
Constantin Posted November 5, 2013 Report Share Posted November 5, 2013 I have recently been using the 742, too, with absolutely no rf-issues (block 24- could it be block dependent?). I used it with a CMIT and a CMK641. And I tried it with a Rycote INV7 and a Cinela Osix, outdoors a standard Rycote WS rig. In all cases we used the Rycote XLR holder to mount the 742 and a short Canare XLR jumper. The OP mentioned something about the connection of the 742 to the mic/cable, and in my case this was a bit loose, too. It allowed the 742 to move a bit on the boom. I added one of those Rycote rubber rings they used on the older style suspension. It's a very small but thick one. This now sits between the 742 and the mating XLR plug, ensuring firm fit for the TRX. There is no movenent now and it all works quite well Quote Link to comment Share on other sites More sharing options...
Matthias Richter Posted November 5, 2013 Report Share Posted November 5, 2013 Using B24 myself. Having 2 CMIT and both show the same symptoms it has to be the 742. Interesting that Constantin got clean signal using the same configuration as I do. Makes me wonder if there really is everything to specs with my 742 although it just came back from testing at Zaxcom - where the rented CMIT showed the RF sensitivity too. When doing tests with the 742 make sure you don´t touch any metal in the signal chain (mic body, XLR connector etc) as this will reduce / eleminate the RFI (as stated by the OP) Quote Link to comment Share on other sites More sharing options...
greg sextro Posted November 5, 2013 Report Share Posted November 5, 2013 Matthias, not that it should matter, but how old are your CMITs? I have found an EMC to EMC jumper helped me with an older CS3e that was picking up RF from a 992. all my other shotgun mics seem to be ok. Quote Link to comment Share on other sites More sharing options...
Matthias Richter Posted November 5, 2013 Report Share Posted November 5, 2013 I´m using an EMC connector on the various suspensions too which helped a bit. My CMITs were bought in December 2006. But since Zaxcom rented a (new) CMIT from Redding audio and found the same RFI I doubt it to be the age of my mics. Quote Link to comment Share on other sites More sharing options...
Cloud Wang Posted November 8, 2013 Report Share Posted November 8, 2013 my 742 is blk24 as well,and my cmit5U,cmit2u and 641 never got any RF issue from either 742 or 942 even in extreme distance ( side by side). My ccm8 and Neumann 82i got RF noise when nearby the whip antenna my 5U was purchased in 2010 or 2011 i think, 2U this year. maybe a call to ask Schoeps if they have done any improvement for 5U in the recently years would help. Quote Link to comment Share on other sites More sharing options...
Matthias Richter Posted November 8, 2013 Report Share Posted November 8, 2013 Interesting. Was in contact already and they said there was no Rfi improvement on the 5u. I sent them an email about two fellow mixers having no probs with the same config. Will see. When using a rightangled antenna on the 742 and have it pointing in the opposite direction of the CMIT the signal is almost clean. What´s also interesting: just mounting the Cinela with the CMIT and the 742 onto a boom pole reduces the RFI extremly. Quote Link to comment Share on other sites More sharing options...
Cloud Wang Posted November 8, 2013 Report Share Posted November 8, 2013 ah i mean the super cmit2u,the digital cmit Quote Link to comment Share on other sites More sharing options...
Matthias Richter Posted November 8, 2013 Report Share Posted November 8, 2013 Just got a reply from Schoeps: nothing has changed in the electronic design of the 5U. They have changed the color material, all screws are fixed now and the contacts are made from diff. material. And since Zax tested with a new CMIT but still had that RFI I am quite certain that it is not my particular mic. Quote Link to comment Share on other sites More sharing options...
bendybones Posted March 29, 2014 Report Share Posted March 29, 2014 Some mics have RF problems and this is one of them. If you use the TRX742 at the bottom of the pole the problem will go away. We have an RF circuit that we can put in the XLR at the bottom of the MIC that will also help to eliminate the problem with the microphone. Glenn Hi Glenn, any further news on this circuit? How would i get that for my mic? And is it a modification that could eventually be applied directly to the unit? Quote Link to comment Share on other sites More sharing options...
ChineseScissorhands Posted May 3, 2014 Report Share Posted May 3, 2014 Last midnight,I tested my gear.Unfortunately,I have this RFI problem too....... Sanken CS3e ---> Canare 30cm---->TRX742 B26---->Rycote Blimp plus Ambient QAT Top Tip---> loud RFI Sanken CS3e ---> Canare 30cm---->TRX742 B26---->Sennheiser Blimp-------> Very loud RFI Neumann KM183/184--->Any way setup--->Clean Why No one tell me before I bought two CS3e and Two 742..... Quote Link to comment Share on other sites More sharing options...
RadoStefanov Posted May 3, 2014 Report Share Posted May 3, 2014 have you tried the new XR modulation? Quote Link to comment Share on other sites More sharing options...
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