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Wireless Mic Interference - FCC Enforcement

Discussion in 'Sound, Music, and Intercom' started by mbenonis, Apr 22, 2008.

  1. mbenonis

    mbenonis Wireless Guy Administrator

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    From the CGC COmmunicator:

    I thought this would be of interest to everyone here. Note that 839 MHz is right in the middle of the CDMA cellular bands. Nevertheless, it is very important that you use good engineering practices with your wireless equipment, and ensure that you're not interfering with licensed users! Remember that everyone here is unlicensed, and could theoretically get a letter just like this (though the chances are fairly remote if you're not interfering with anyone).
     
    lieperjp, museav and MNicolai like this.
  2. MNicolai

    MNicolai Well-Known Member Fight Leukemia

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    I get little freaked out every time I see something like this happen. It makes it scary when Shure has to put out a press release stating their equipment will remain legal for years to come.

    I know there are a ton of other threads about this, and I've read through them, plus the news articles, the bills, even sent letters to my man in Washington, but I still have a question about it...

    We've got a new PAC going up here later this year, are there any UHF microphones that won't get caught under the ax? I ask because we've got 20 mics we'll be buying and I don't know if there's a way around this regulation or if it's an unavoidable evil to which we must file for licensing.

    I'd hate to think that in the upcoming year any wireless mic not licensed with the FCC might be illegal contraband if used.
     
  3. mbenonis

    mbenonis Wireless Guy Administrator

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    Yes - stay below 698 MHz and you should be just fine. Anything above that will be off-limits come next February.
     
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  4. museav

    museav CBMod CB Mods Departed Member

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    There is a difference between equipment being legal for use and operating it legally. While the frequency reallocations may result in some additional frequency and bandwidth limitations and more sources with which you cannot interfere in what bandwidth is left, I believe that nothing is really changing as far as operating wireless mics. Unless you are a licensed broadcaster and using VHF or UHF wireless mics within your licensed bandwidth then you are technically operating illegally, although the practical issue will still be more a matter of not interfering with any licensed users.

    In some ways the vast majority of wireless mic users are getting the worst of it. Because most wireless mics are not actually operated legally, they are not being considered in most legislation. For example, because legal wireless mic operators are addressed in the reassigned broadcast frequencies, the initial White Space legislation that would allow other devices to operate in unassigned frequencies does not actually include wireless mics. It doesn't change how most people would use their wireless mics but it opens up the possibility of you being legally at fault if your wireless mic interferes not only with a licensed broadcast but also with someone's wireless communications or entertainment device (nor would those devices need to avoid interfering with unlicensed wireless mics). This potentially concerns me more than the current frequency reallocations.

    There are some mics available and coming out that operate in different frequency bands, including 900MHz and 2.4GHz, but most of these have some other potential issues such as those not frequencies already being fairly crowded in some areas.

    It is not all doom and gloom, for many wireless mic users very little may change other than perhaps having to change frequencies. For most wireless mic users the available frequencies will likely decrease while the number of sources with which you cannot interfere may increase. Also, the White Space issues may not afffect theatres as much if you have established policies for patrons to turn off all such personal devices, which many already do.
     
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  5. mbenonis

    mbenonis Wireless Guy Administrator

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    Very well said, Brad.
     
  6. MNicolai

    MNicolai Well-Known Member Fight Leukemia

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    So would you say that as a theatre it is safe enough to uphold such a policy and we should be okay?

    Basically, I want to know if I should be raising flags to make sure our audio contractor doesn't screw it up, as I've seen the same contractor screw other venues up. I would not be surprised to see, come November, that they ignore the regulation and clear their shelves of 20 quasi-legal wireless systems on us.
     
  7. mbenonis

    mbenonis Wireless Guy Administrator

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    What type of mic systems will you be specifying for your new PAC?

    Ideally, you should try to find a way to buy the wireless directly from a wireless vendor (Systems Wireless, Production Radio Rentals, Professional Wireless/Masque, etc). These companies know what is going on and will make sure your wireless system is in order.

    Short of that, be very very specific in your equipment order. Ensure that you specify EXACTLY what you want - make, model, frequency bands, etc - so that there is no way to screw it up. Do some pre-planning as well to make sure your system will work when you get it, and if you can afford it, get a consultant who knows RF well to guide you through the process.
     
  8. museav

    museav CBMod CB Mods Departed Member

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    I have to disagree with Mike a bit. He has a great point about getting someone who really knows wireless involved, but I'm not sure about separating the equipment purchase. Whenever you start breaking up a system you create a point of coordination and potential finger pointing. If you don't get sound from a wireless mic you potentially have two parties involved instead of one.

    What I might do instead is either hire one of these experts on a consulting basis or require the Contractor to use their services. That should let you get the benefit of their expertise while still keeping the liability for the whole system installation on the Contractor.

    If you are real concerned, you might even have them delay ordering the actual wireless components until after the facility is further along, once the main building and walls are up you could have someone do an RF survey on site to get an even better idea of what is really there.
     
  9. howlingwolf487

    howlingwolf487 Active Member

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    So why are you using this guy again?
     
  10. MNicolai

    MNicolai Well-Known Member Fight Leukemia

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    There are higher powers, and I'm technically an outside party. There are a couple faculty members in the adjacent school as well as a couple administrators that want me to be the TD once the space opens though.

    In my mind no company named ProAudio Designs should be stupid enough to put a fixed window on a sound booth...

    One venues I've worked in that they helped out on had so much trouble with their wireless mics and interference, but PAD didn't help them out much and they ended up have to get a working frequency list directly from Shure that was flawless. Funny how that works.
     

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