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Device to scan and display RF in an area?

Discussion in 'Sound, Music, and Intercom' started by Sayen, Jul 31, 2012.

  1. Sayen

    Sayen Active Member

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    Don't laugh. This makes sense in my head, I just don't know if it exists in the real world.

    I'm trying to pin down some wireless issues in a venue, across different types of gear (headset, mics, DMX, etc). Is there a device that would let me scan to see what frequencies are in use around me? Something I could borrow or rent? It seems like there must be something, since I've heard of wireless phone carriers driving and scanning their frequency ranges.

    I know Sure and Senheiser list frequencies in a given area, but I'm seeing weird changes over the course of a day, and I'm trying to figure out exactly what's happening. Doesn't help that the venue is right next to a large cell and radio tower.
     
  2. zmb

    zmb Well-Known Member

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    A RF spectrum analyzer? This is one site I found and they aren't cheap. But pro audio is listed as one application.
     
  3. DaveySimps

    DaveySimps CBMod CB Mods Premium Member

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    I own the Invisible Waves X software and hardware. It is great, very easy to use, and the perfect tool for the job, but as ZMB mentioned, not cheap at all. I have not found anyone that rents them, but it is certainly worth a call to vendors in your area.

    ~Dave
     
  4. Footer

    Footer Senior Team Senior Team Premium Member

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    Give a call to clearwing, guarantee they have one and would probably come out and do an analyse for ya.
     
  5. themuzicman

    themuzicman Active Member

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    Try Intermod Analysis Software like IAS
     
  6. mbenonis

    mbenonis Wireless Guy Administrator

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    Spectrum Analyzers aren't cheap. Even the not-quite-lab-grade ones are generally in the thousands of dollars range. The reason is simple: a Spectrum Analyzer needs to be able to handle a very wide dynamic range of signals with very good resolution, with a very fast scan rate.

    What kind of changes are you seeing over the day? We may be able to pin the problem down based on the patterns.
     
  7. Stookeybrd

    Stookeybrd Active Member

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    They exist. In fact, my job would be impossible many times without one. Here is a shot of my scanner at recent gig I did with over 150 frequencies. My TTI is invaluable, and I couldn't imagine doing shows without it.

    All of these scanners cost at least $1,000 and can probably be rented from somewhere. I know shops here in New York rent out the TTI and Kaltman scanners.
    Kaltman Creations
    Invisible Waves
    TTI PSA1301
    ICOM PCR2500


    However, there is this very interesting unit for $130. It is back ordered and fairly new to market, so I have yet to get me hands on it. I cannot provide a recommendation one way or another.

    Like mbenonis tell us more about the issues you are experiencing. Pops? Fuzzy sounds? Swishy sounds? Audio dropping out? What gear are you using and what frequencies is that gear on?
     
  8. Sayen

    Sayen Active Member

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    Thank you! I knew there had to be something, but I was Googling with all of the wrong phrases apparently.

    The biggest issue we have is inconsistency. Wireless gear works fine in the morning/afternoon, but as soon as we have a performance in the evening we have issues. We have a wireless ClearCom system that works great. One of my techs took her headset next door to the 7-11 and was still able to talk to us with just a little fuzz. Then during an evening event it just wouldn't work. We checked base station and belt packs, batteries, everything...just couldn't get it to work. Everything was fine the next morning of course.

    We use a CityTheatrical ShowDMX unit occasionally. Everything will test fine during setup, and during a live run we'll see dropouts and low signal strength from the receiver.

    Likewise, with our Sure mic system - and I'll have to get back to you on the frequencies, although I know they're legal (600mhz system?) - we'll manage a rehearsal fine, and then end up with drop outs and fuzz during the performance. I know some of this is to be expected with wireless, and the golden rule in theater is sometimes that what worked in rehearsal will fail live, but the performance quality of the equipment changes significantly, beyond just a few pops and fuzzes. I figure that something like a spectrum analyzer will let me see what's going on quickly, and if there really is a change in what noise is in the air during different times of the day, especially in our different performance venues.
     
  9. PolishGuy

    PolishGuy Member

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    Have you done anything in house to troubleshoot these issues? Tried switching to a different frequency on the receivers just for giggles? How consistent is it? Is it every wireless device or just a couple or combination dropping out while others work fine? Have you run a check through Shure/Sennheiser's frequency list on your zip code yet?

    A spectrum analyzer is an option of course, but if it turns out to be fixable by just jumping to a different frequency, you'll kick yourself over the $$$ :p
     
  10. TimmyP1955

    TimmyP1955 Active Member

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    When Kaltman first came out with a scanner, I read a lot of negative comments about it. TTi seem to be universally liked.

    Have you entered all your frequencies in coordination software to make sure that you don't have any intermod problems? If not, do so. Then scan both with everything up and running, and on an off night so you can see what's coming in from elsewhere.
     
  11. BNBSound

    BNBSound Active Member

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    Find a ham radio operator in the area and borrow their scanner. A good one will let you sweep the spectrum continuously and with the squelch turned way down you might catch an issue. The problem with most scanners is that they're FM only or if they do have AM it's only enabled for broadcast and aircraft ranges. Listening on AM will give you a better shot at hearing something because the detector on an FM receiver depends on having a lock on a signal. Even without one, if the scanner stops in the middle of your wireless range and shows full scale on the meter you might have some background RF issues.

    More likely than not you've got conflicts with local DTV transmissions and intermod between the units. Check out the manufacturer's website. Chances are they've got a web utility or software you can download that will take your zip code and model numbers into account and give you channels that are more likely to be free and won't interfere with each other.
     
  12. wiscolighting

    wiscolighting Member

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    Someone else mentioned Clearwing they probably can help you out and are right there in Pheonix also up here in Milwaukee. There are some software's out there that do not sweep but are able to check all of the frequencies in use you have to input them into the software and it will compare and suggest frequencies based on your location I have heard of one RF Guru with mixed reviews) and know of one in development from some people I know in the industry. Check with the Wing they are good guys for the actual equipment you can shell out thousands as someone else mentioned.
     
  13. Ric

    Ric Active Member

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    Hi all,
    I'm looking for a device to allow me to scan frequencies and see if there's any issues with RF in the area, or what is being used during performances.
    I'm specifically looking for Radio Mic /Wireless comms frequencies (520-800 MHz range), but if it also covered WiFi (2.4GHz) that would be a bonus.

    PC based connectivity would be a bonus.

    I am aware of the Sennheiser 300 series and their software, and that may be an option when we upgrade our radio mics soon.

    Is there anything in a low end price range, hundreds, not thousands, that anyone has found?
     
  14. standup

    standup Member Premium Member

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    You can do the same thing with Shure Axient, UHF-R, ULX-D and PSM1000 wireless systems as well. I'm not going to start the Shure vs. Sennheiser war but they both do offer that feature.


    The RF Explorer has a version that will supposedly go up to 2.7 gHz. I haven't used it, nor can I find a lot of reviews, but at ~$275, it could be a steal.
     
  15. themuzicman

    themuzicman Active Member

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    The RF explorer is pretty awesome, I use one on a regular basis and it's what the majority of light duty users need. Most people only need the $165 sub 2.4gHz version too.
     
  16. Ric

    Ric Active Member

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    Thanks guys,
    2 out of 2 votes for RF explorer. Seems like something I should take a good look at!
     
  17. Stookeybrd

    Stookeybrd Active Member

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    A third vote for the RF Explorer. It is even more impressive with the software. With a little work I have a script that will run a full spectrum scan, generate a .csv file and import it into IAS. It's awesome.
     
  18. RonaldBeal

    RonaldBeal Active Member

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    I have run into the issues mentioned by the OP, and suspect you don't need a spectrum analyzer to get to the root of the problem. The CT Show DMX works in the 2.4 MHz region of the RF spectrum. I suspect your Clear-Com does too (A lot of their wireless stuff is 2.4MHz, and some is on other bands.) The problem arises when several hundred audience members show up, and forget to turn WiFi off on their smart phones. WiFi is also 2.4MHz, and once all those phones start cluttering up your RF space, RF performance drops of dramatically. Check your Clear-com to see if it is indeed 2.4MHz. You can get Ubiquitiy's Air view, or the WI-Spy 2.4 for $40-$80, both are 2.4MHz only USB spectrum analyzers that will confirm the cause of the problem.

    Solutions: directional antennas, or change to a product that uses different frequencies.
    Good luck.
    RB
     
  19. Stookeybrd

    Stookeybrd Active Member

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    2.4GHz, yes the Show Baby and Tempest have their frequency bands in the 2.4GHz ISM band. (Clearcom's Tempest also has a 900MHz option)

    The issues that arises when doors open and hundreds if not thousands of phones enter the vicinity is most commonly a friendly distributed denial of service. The access point or router that is running a show control computer or the transceivers in the gear has to deal with so many query pings and collisions that their own data stream cannot make it through.
     

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