Anyone getting RF interference w/ 702 and G2? at DVinfo.net

Bill Ravens · March 11th, 2007, 01:38 PM

I've been running a Sound Devices 702 CF recorder in parallel to my HDV camera to record higher quality sound than what I can get with HDV audio compression. I use the on-board audio to sync up the external audio in post.

I recently bought a Senn Evolution G2 package for wireless mic connections to the 702 recorder. I'm getting so much RF interference from the 702 recorder that the G2 experiences audio dropouts at any range from the transmitter, making the Senn useless.

Anyone else found a way to deal with this problem? Things work fine as long as the 702 isn't powered up. As soon as it powers up, my signal goes unpredictable.

Daniel Epstein · March 12th, 2007, 08:02 PM

Bill,
Does the interference end when you Turn off the Sound Devices? Have you tried changing frequencies on the Sennheiser? If this happens on all frequencies you should call Sound Devices and ask them if they can confirm this is an issue? Also try getting another unit to see if it a problem with yours or a more widespread issue. Most devices are not supposed to emit large amounts of RF. I recently worked on a job with a 744 and 722 with up to 8 Lectrosonics with no issue but they use a different part of the spectrum than the G2's. You might have to get a different radio mic if you want to use the Sound Devices. HTH

Bill Ravens · March 13th, 2007, 08:43 AM

Daniel...

Thanx for your reply. Sound Devices acknowledges an RF problem with certain frequencies. I changed frequency and the problem seems to have gone away...whew!

Daniel Epstein · March 13th, 2007, 06:02 PM

Quote:

Originally Posted by Bill Ravens

Daniel...

Thanx for your reply. Sound Devices acknowledges an RF problem with certain frequencies. I changed frequency and the problem seems to have gone away...whew!

Bill,
Well done. I hope they are promising you a cheap upgrade to the next model or a retro fit because it sounds like an issue which more people will run into. Have they published this issue or put up a notice on the website? I should get some people to do some tests to see what frequencies are being disrupted. If it is very narrow it might not be a big deal but if it is more significant than I could see it being a headache for soundmen.

Will Kinsinger · March 13th, 2007, 11:02 PM

This issue is well documented and discussed at RAMPS. The rf is leaking out through the LCD screen and the plastic area behind the battery. The best solution to date is finding a clearer freq and/or putting some distance between the 7xx recorder and your receivers. As little as 6 inches can make a big difference.

Hope that helps,

Will

Bill Ravens · March 14th, 2007, 07:32 AM

Indeed. At the Sound Devices website, they have quite a detailed description of the problem, as well as measurements they've conducted that show, quite precisely, where the RF frequencies are.

Daniel Epstein · March 14th, 2007, 04:20 PM

Bill,
Do you have a link for description on their website? I did a quick browse of the website and didn't find it using their search for RF Interference last night.

March 11th, 2007, 01:38 PM	#1
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	Anyone getting RF interference w/ 702 and G2? I've been running a Sound Devices 702 CF recorder in parallel to my HDV camera to record higher quality sound than what I can get with HDV audio compression. I use the on-board audio to sync up the external audio in post. I recently bought a Senn Evolution G2 package for wireless mic connections to the 702 recorder. I'm getting so much RF interference from the 702 recorder that the G2 experiences audio dropouts at any range from the transmitter, making the Senn useless. Anyone else found a way to deal with this problem? Things work fine as long as the 702 isn't powered up. As soon as it powers up, my signal goes unpredictable.

March 12th, 2007, 08:02 PM	#2
Daniel Epstein Trustee Join Date: Jan 2006 Location: New York, NY Posts: 1,267	Bill, Does the interference end when you Turn off the Sound Devices? Have you tried changing frequencies on the Sennheiser? If this happens on all frequencies you should call Sound Devices and ask them if they can confirm this is an issue? Also try getting another unit to see if it a problem with yours or a more widespread issue. Most devices are not supposed to emit large amounts of RF. I recently worked on a job with a 744 and 722 with up to 8 Lectrosonics with no issue but they use a different part of the spectrum than the G2's. You might have to get a different radio mic if you want to use the Sound Devices. HTH

March 13th, 2007, 08:43 AM	#3
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	Daniel... Thanx for your reply. Sound Devices acknowledges an RF problem with certain frequencies. I changed frequency and the problem seems to have gone away...whew!

March 13th, 2007, 11:02 PM	#5
Will Kinsinger New Boot Join Date: Dec 2005 Posts: 5	This issue is well documented and discussed at RAMPS. The rf is leaking out through the LCD screen and the plastic area behind the battery. The best solution to date is finding a clearer freq and/or putting some distance between the 7xx recorder and your receivers. As little as 6 inches can make a big difference. Hope that helps, Will

March 14th, 2007, 07:32 AM	#6
Bill Ravens Join Date: Nov 2001 Location: santa fe, nm Posts: 3,264 Images: 10	Indeed. At the Sound Devices website, they have quite a detailed description of the problem, as well as measurements they've conducted that show, quite precisely, where the RF frequencies are.

March 14th, 2007, 04:20 PM	#7
Daniel Epstein Trustee Join Date: Jan 2006 Location: New York, NY Posts: 1,267	Bill, Do you have a link for description on their website? I did a quick browse of the website and didn't find it using their search for RF Interference last night.