Microphones Serious Sennheiser Problem!

[adude23]

Did a gig tonight with two sennheiser ew135 G2 Radio mics and one works perfectly but the other crackles and was making popping and fuzzing noises, Now what am i doing wrong??? They're both on different channels but i don't know what else to do?
Urgent help needed please if anyone out there knows?
Thanks guys
~Adude~

 

[waynehoskins]

Probably there's co-channel interference -- that is, a strong transmitter on the same frequency. Most of these interfering transmitters are known as Television Transmitters and are the primary users of the space. If you turn off the affected transmitter, does that receiver still show signal? If so, you've for certain got a co-channel signal.

That's my guess.

 

[adude23]

That was my thought i thought something was interfering but i've tried it on a couple of different channels by using the "scan" feature on the receiver itself and then tuning the transmitter into the same freq. I will defiantly try turning the transmitter off though and see if i'm getting any AF levels on it
anyone else have an idea the more the better really?
thanks,
~Ash~
Oh by the way the XLR's going from the reciever to the board is quite long could this be affecting it atall or maby the lead in general?
cheers,

 

[Sony]

Oh by the way the XLR's going from the reciever to the board is quite long could this be affecting it atall or maby the lead in general?
cheers,

It could be a bad XLR Cable if the leads or solder joints are corroded or dry. Try replacing the cable and if that doesn't work then it's most likely a bad transmitter, the microphone itself has gone funky, or you're still getting interference from somewhere.

 

[howlingwolf487]

I agree that your wireless mic is getting stepped on by something else (a TV station, for example).

First, go to Sennheiser's Frequency Finder and fill in the appropriate information. That will help you see what stations are around you. Also, look on the back of the receiver and find out what frequency range you have (A, B, etc.).

Note which channels are open, but realize that they may be taken by other low power VHF/UHF devices in the area.

Second, after finding the open channels in the area, go to the BANK menu on the receiver and set it to the one that covers the most open frequency range in your area (for me in Huntington, IN it's Bank 8). The SCAN function only scans within the selected BANK, so once you have that, you can select the appropriate channels.

Third, tune the channels so that they are as far away from anything else that might interfere (frequency-wise, that is).

That should get you going. As far as the XLR length goes, the output from the receiver is pretty much line level, though you can adjust the AF Out in the menu options. You shouldn't have any problem with it.

The only other sound that the wireless mic might make is due to clipping the handheld/beltpack. If that's the case, go to the transmitter's menu and adjust the SENS. (Sensitivity) to either -20 or -30.

We just got 8 new wireless mics, so I've been programming/adjusting them.

 

[mbenonis]

I agree with everyone above. Check to make sure you're not operating on an occupied TV channel, and do your best to make sure there are no other devices which could interfere.

Another thing to try is (assuming both mics are in the same block), switch the transmitter frequencies and see where the problem goes. If it switches from one receiver to the other, then the problem is internal to the transmitter. If it stays on the same receiver, then it's either the receiver or the RF channel. Now leave the transmitters swapped, and switch up the receivers. If the problem follows a receiver, than it's the receiver. But if the problem switches, you know it's the RF channel and not a gear issue. Does that make sense? At the end, the first system will be on the second frequency, and vice versa.

If the problem is with the gear, it'll need to be fixed. If it's with the RF channel, just keep trying new ones until you get a clean channel. Specifically, try a different TV channel.

 

[waynehoskins]

By the way, at least where I am, there are no clear channels in the 600-meg block. I've got two transmitters there .. to be stable, they have to be in the 650-656 meg channel. It's relatively clear, but there's a LP transmitter 30-50 miles away there. The whole 30 megs (- 5 channels) below 650 I have solid digital hash about S-9. It's tolerable there except occasionally the local link would be just a touch below the interference. All good since I moved them up into a less-unclear channel.

Being EW135s, those are handheld transmitters with 835 capsules, so there's no cable between mike and transmitter to have a break (which on a bodypack set would be the first suspect). So check the radio link and check that XLR cable from the receiver.

 

[mbenonis]

It's relatively clear, but there's a LP transmitter 30-50 miles away there.

ATSC or NTSC? If it's NTSC, did you put the wireless in the slots between the carriers, by chance, or just somewhere in the channel?

 

[waynehoskins]

ATSC or NTSC? If it's NTSC, did you put the wireless in the slots between the carriers, by chance, or just somewhere in the channel?

I didn't notice. When I moved them, I observed that the interference (solid 30 megs of signal) was nothing I'd seen before, and so I just found a spot that was clear and put them there. Clear, at least, inside the building on those quarter-wave verticals.

I stuck them at 650.5 and 651.5, being far enough apart from each other and also safely inside the "safe zone" there. It hadn't occurred to me until the other month (August after the NPRM) that those were DTV signals I was having trouble with, and at Christmas it'll be two years since I moved the transmitters.

I'm thinking it's probably an NTSC channel, but I should check. I didn't even know there was something there until August .. which means it's probably a good idea to put them in the clear between the carriers to minimize the interference to everybody else, being a far-away LP station, huh?

 

[adude23]

Thanks everybody lots of tips which i will put into practice tonight!
I'm HOPING it's just a lead or channel problem that can easily be fixed
Thanks guys i'll let you know how i get on!
~Ash~

 

[TimmyP1955]

It might not be RF: Make sure that phantom power is turned off on the console channel that the receiver is feeding. Some of these things don't take kindly to seeing phantom on their outputs.