fiore Posted September 25, 2015 Report Share Posted September 25, 2015 Hey all, I'm currently on location and I'm having a bit of an issue. I'm attempting to power and Km150 with a lectro HM plug and I'm getting 0 signal. I've tested it with 2 km 150s. Both Mics work fine when cabled and the HM works fine with a cmit 5u. Any ideas? Quote Link to comment Share on other sites More sharing options...
David Waelder Posted September 25, 2015 Report Share Posted September 25, 2015 The shorter Neumann's (KM 140, KM 150, KM 185, etc.) have sometimes been problematic with radio hook-ups. They often require reverse polarity - admittedly a tricky business if you are connecting directly to a plug-on transmitter. Try connecting with a polarity reversing cable as a test before diving into connections on the HM plug itself. Curiously, I never had any difficulty using the longer Neumann's (KMR 81, 82), only the shorter mikes. David Quote Link to comment Share on other sites More sharing options...
fiore Posted September 25, 2015 Author Report Share Posted September 25, 2015 I'll give it a shot thanks! Quote Link to comment Share on other sites More sharing options...
karlw Posted September 25, 2015 Report Share Posted September 25, 2015 David is correct. The longer (KM81i, KM82i) are transformer-output microphones (purple badge), and thus are truly balanced. The KM100 Series units have transformerless (active) outputs (red badge), and are not truly balanced. The polarity reversing adapter should take care of the problem. Quote Link to comment Share on other sites More sharing options...
bralleput Posted September 25, 2015 Report Share Posted September 25, 2015 "The polarity reversing adapter should take care of the problem." But will make your rig (KM 100,adapter,HM) a bit bigger... Quote Link to comment Share on other sites More sharing options...
axel Posted September 26, 2015 Report Share Posted September 26, 2015 I got a UH400a Tx (earlier model of HM, but basically the same input circuitry) and a KM140 capsule, polarity reverse worked for me, but the setup was susceptible to HF interference. Specially shielded Neutrik plugs slightly improved the performance, OK for quick installations where you can bring the Tx away from the mic, but I would not use the combo on a boom rig. UH400a works great with the KM 184 though, that is the unibody version of the short Neumann series with the non detachable mic capsules Quote Link to comment Share on other sites More sharing options...
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