• Audio

  Wireless Mic Interference

  Posted by Thomas Hughes on June 8, 2011 at 5:50 pm

  I film events in the San Francisco bay area. I send two w/ms out to each shoot. I’ve got the FCC chart:

  https://www.fccinfo.com/CMDProFacLookup.php?sCurrentService=TV&sCity=San+Francisco&sState=CA&tabSearchType=City+State+Search

  that shows what tv stations exist in my area, what their power (kW) is and whether they’re digital or analog. Then I have the corresponding Lectrosonics chart (those are the mics I use):

  https://www.lectrosonics.com/images/PDFs/tvstationsfrequencyblocks.pdf

  that show me what frequency range each tv channel operates in. So with that info, I’m able to determine what frequencies are available to set my mics on.

  My question is what tv stations do I not need to worry about? There are a lot of tv stations in my area. Do I need to worry about all of them? Each station has a different kW output. They range from 4.5 kW to 1000 kW. And are both digital and analog stations a problem or just digital?
  I know that another factor is how far away the station is from where I’m working, but any input is greatly appreciated. Thank you.

  Thomas H

  John Fishback

  

  replied 15 years, 2 months ago 3 Members · 3 Replies
• 3 Replies

• 

  Ty Ford

  June 8, 2011 at 10:19 pm

  Hello Thomas and welcome to the Cow Audio Forum.

  First a little legal stuff. It is against FCC rules to fire up a transmitter on the same frequency of an existing TV station within 50 miles of said station. Does it happen? Yes.

  Analog and digital both need to be avoided. The digital will be more obvious. I don’t think there are any analog TV stations on the air in the US anymore.

  Regards,

  Ty Ford

  Want better production audio?: Ty Ford’s Audio Bootcamp Field GuideWatch Ty play guitar
• 

  Thomas Hughes

  June 8, 2011 at 10:29 pm

  Ty, Thanks that’s very helpful. Generally, do you think it’s necessary to be a full 50 miles away to avoid interference? Tx

  Thomas H
• 

  John Fishback

  July 4, 2011 at 7:47 pm

  Another useful tool from Sennheiser:

  John

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