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Wireless Spectrum Analyzer on the Cheap 94

PennyManDeux writes "There's an article over at TheTechLounge looking at the Wi-Spy wireless spectrum analyzer. Here's a quote: 'Although most wireless boxes are able to push through the lower amounts of interference, some people, such as those living in apartments or otherwise deluged with many wireless signals may have problems. It is with this dilemma in mind that the people at MetaGeek created the Wi-Spy spectrum analyzer.' Cool thing is, it's only $100..."
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Wireless Spectrum Analyzer on the Cheap

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  • Why could these guys not had this a few years back when I owned a WISP?!? Just goes to show you, timing is everything. With the improvements in Wireless, and the accompanying hardware/tools, it seems that more people will be using it for commercial implementations.
  • by postbigbang ( 761081 ) on Tuesday June 20, 2006 @11:23AM (#15569526)
    Yes, it's under $100. That's news. But many other comparisons to the higher-priced analyzers aren't there.

    1. Does it do channel characterizations? Apparently not.
    2. Does it have channel reticules? Apparently not.
    3. Does it do 802.11a? Apparently not.
    4. Does it have enough resolution to find Bluetooth and other spread-spectrum devices? Apparenly not.
    5. Can it identify specific kinds of interfering devices, like 2.4Ghz phones, microwaves, door openers, etc? Apparently not.

    I say apparently not because none of this functionality, commonly found in other spectrum analyzers of this type, is even mentioned. It's nice to have a cool A-to-D converter in the 2.4Ghz region, but comparing this to Cognio or Air Magnet is like comparing a bicycle to a Porche. I can buy a bicycle for under $100. I can barely touch the ugliest old 914 Porche for $3K.

    Don't be fooled by price, or comparisions that hardly scratch the surface of what diagnostic tools are all about. For under $100, it's pretty damn cute. But it's just the basics.... and minimalist basics at best.
    • Actually your response isn't fully accurate. Rich clearly states that it does not do 802.11a.
    • by Anonymous Coward
      I say apparently not because none of this functionality, commonly found in other spectrum analyzers of this type, is even mentioned.

      How many high end frequency analyzers count as "of this type?" It's a $100 USB accessory. You wouldn't expect the same performance you'd get from a professional grade unit, would you? You mention some exceptionally useful functions, but you wouldn't expect them in a $100 box. Hell, the companion software for some of the nicer analyzers costs way more than $100. As for "oth
    • by Resseguie ( 602552 ) on Tuesday June 20, 2006 @01:22PM (#15570555) Homepage
      A better review is available from Tom's Networking, including comparison to one of the $4000 Cognio devices: spy/ []

      Comparison table on page 2: spy/page2.html []

    • Do you really think anyone is dumb enough to think that this $100 device is going to do everything a $5000 device does? You seem to think there's some big deception going on here. I think it's pretty obvious that this thing is aimed at the low end of the market of people who just want to see where interference is coming from rather than operating totally blind.

      I know that a $50,000 Cessna isn't going to be the same as a 100 million dollar 747, and I'm not fooled into thinking this when someone talks about
      • The article thinks it's a glowing thing because it costs >$100.... without any comparisons to others-- even the higher priced ones.

        Yes, it's nice to see things in the 2.4Ghz band. It's very simple and that simplicity can be useful for those looking for simple amplitude nearby. Beyond that, there are lots of things that it doesn't do.... including letting someone using this as a tool identify lots of signal types-- not just that there might be something inside the boundaries.

        So, the dialog goes: Ug. Look:

        • The article thinks it's a glowing thing because it costs >$100.... without any comparisons to others-- even the higher priced ones.

          Maybe because the people the device is aimed at have no interest in something that costs $5000 and up. Why compare this thing to something that you'll never use? When I'm looking for an economy car I don't want comparisons to a $50,000 bus. The comparisons should be toward the tool that people who might buy this thing currently use. That's either nothing (guessing the pro
  • Wires, baby Wires (Score:5, Insightful)

    by stratjakt ( 596332 ) on Tuesday June 20, 2006 @11:23AM (#15569528) Journal
    Wires: the new wireless! []

    You can analyze spectrums all day long, meanwhile me and my Cat 6 are enjoying gigabit speeds! Thats some fast, fast porn baby!
    • Maybe so, but how fast is your connection to the internet?

      It's not likely to be faster than the working speed of either cat 5 or wireless.
      • Faster? Nah. More reliable? Hell yah.

        I never whine about getting fragged in an online deathmatch because someone reheated a cup of coffee in the microwave, or the phone rang, or the channel 5 news van ran a remote feed too close to my house.

        I whine because the guy was CAMPING AND THATS LIKE TOTALLY GHEY MAN STFU N00B kekekekekeke
        • Ok, I know you were making fun of those people, but that's a bit of a pet peeve of mine: people who call others "noob" for using the most effective weapon in the game, or choosing their battles carefully. People, realize that if a less experienced player than you is killing you more than you're killing them, they are using superior tactics. Adapt. (ok it's possible they're outright cheating, but that's outside the scope of this rant.)

          Rising to their challenge is exactly what makes the game fun, not rackin
    • Re:Wires, baby Wires (Score:3, Interesting)

      by alexburke ( 119254 )
      me and my Cat 6 are enjoying gigabit speeds!
      I'll see your expensive Cat 6 gigabit network and raise you my inexpensive-yet-just-as-fast Cat 5E gigabit network. Why did you bother with Cat 6?
      • Actually it's all Cat 5e, the only Cat 6 cable I have is from switch to my main desktop - and even then just because it's what I grabbed at best buy.
      • To me there are no real advantages to these speeds; since the computers/server is mostly the bottleneck unless you upgrade everything and fine tune you do get some performance out of it; but the price of such full upgrade still doesn't cut it for me...
        • My "older" PC network runs fluently over my CAT-5 network; fully seperated from the company network using some LEVEL-1 [] switches; full speed, my network connectivity never goes down. Although still; it goes fast; but when transferring bigger files like my rec
        • I tried to compare 10/100/1000 differences with a newer PC installed with the intel gigabit networking options, just like 3 of the servers; connected to a gigabit supporting switch to the company backbone. The difference is very minimal;

          Then either you have very slow hard drives in your boxes, or a very cheap Gigabit Ethernet switch. I regularly transfer 5 GB files around my network, and in doing some testing I discovered that between the exact same two machines, when I forced one of them to connect at 100M

    • Yea but I can do the pr0n in every room in my uber 1337 city condo. Bathroom, kitchen, living room, bedroom, balcony, hallway, laundry room, neighbors room, etc. All from my wireless pr0n.
  • Interesting, but... (Score:3, Interesting)

    by evileyetmc ( 977519 ) on Tuesday June 20, 2006 @11:24AM (#15569536)
    It doesn't really solve the problem of interference. Let's say you have a 900 Mhz (old tech, I know) phone, which has constant interference. You buy one of these spectrum analyzers and find, not surprisingly, there is some interference at the 900 Mhz range. So what is someone going to do? Buy another phone, either at 2.4 Ghz or 5.6 Ghz, which would have less interference, but you didn't need a spectrum analyzer to get you to buy the higher frequency phones. You would have done that anyway.
    • by Dare nMc ( 468959 ) on Tuesday June 20, 2006 @12:21PM (#15570049)
      >you didn't need a spectrum analyzer to get you to buy the higher frequency phones. You would have done that anyway.

      to find the biggest offender, radios do go bad.

      I got a SpreadSpectrum 2.4Ghz phone, 2*2.4Ghz access point, and a 5Ghz wireless video link, and 3*2.4Ghz devices accesing the access points, and a Microwave. It all works no problem together (except the microwave kills the video link when in use.)

      My brother has a cordless phone, and 1 AP, and 1 Laptop. His phone knocks his laptop off the network everytime. whats the difference? could be his A.P. isn't switching frequencies when he tried to force it. Could be any other device in his house (or unshielded cable TV) is tieing up all but one frequeny in the AP's range, or it could be a really bad phone. It is cheap to replace the phone, since the problem is obviously tied to it's use, but if it is the A.P. he will likely be fighting the same issue in the future. If a neighbors device steps into the now open frequency at next power outage/etc.

      with this we could look at what the phone, PC, TV, Sat, Laptop, etc each contribute to that spectrum (and walk around the house to find the strongest area to locate.) not just which device pushed us over the edge, and is easiest to power off for a long period. IE maybe he just needs to replace a $2 coax cable, but what a pain to cut the feed for hours while he tests every other scenariao.
      • 900 mhz sucks. Flaky as hell from what I've heard. 2.4 is the best all round solution. 5.7ghz can't penetrate foliage like the 2.4's.

        2.4 will do 25km and 7 mbit aggregate. Perfectly fine for 1.5 mbps home applications.

        I love the SuperNet!

  • Just another toy (Score:5, Interesting)

    by wiz31337 ( 154231 ) on Tuesday June 20, 2006 @11:25AM (#15569550)
    This is surely not a replacement for a spectrum analyzer, but it will give you a general idea of interference in your house.

    I have conducted many site surveys for businesses wanting wireless networks. The purpose of a spectrum analyzer is to pin-point sources of RF interference that may limit wireless connectivity, so that measures may be put in place to reduce RF emissions. You'd be surprised at amount of RF interference generated by industrial equipment, which poses a problem for RF engineers.

    This product merely shows you that you have interference, and lacks the ability to pin-point the source. This product would be better if you could have an external parabolic antenna, but it looks like someone will need to figure out how to jimmy rig a Pringles can antenna to this unit. What can you expect for $100?
  • How about... (Score:5, Informative)

    by the_mind_ ( 157933 ) on Tuesday June 20, 2006 @11:28AM (#15569589)
    A link [] to the actual product page? []
  • You know... (Score:3, Interesting)

    by jagossel ( 973849 ) on Tuesday June 20, 2006 @11:29AM (#15569598)
    You know... it would have been nice to have when I moved into my apartment. Although I never figured why for the past three months my wireless wasn't working on Channel 6, I changed it to Channel 10 and all of a sudden my Wireless network works fine now... unless I use my microwave, that's another story.
    • You don't need such a device to figure out why channel 6 isn't working, the answer is simple: ignorant neighbors. Almost every manufacturer defaults to channel 6, so that explains a good portion of it. Perhaps you also have a neighbor using one of those turbo modes (eg. 108Mbps "SuperG" cards). Those devices typically do horrible (well very selfish) things to the spectrum like channel banding and are typically required to operate on channel 6 so they don't interfere with frequencies above channel 11 or b
  • by Anonymous Coward
    Netstumbler will do most of what you need done and it's free. Here's a link to a tutorial. 589131 []
    • Nope! (Score:3, Informative)

      by RebornData ( 25811 )
      Netstumbler only shows you other *wireless networks*. Wi-Spy shows you *all* RF interference in the 2.4 GHz spectrum, such as that caused by cordless phones, microwave ovens, etc...

    • Netstumbler will do most of what you need done and it's free

      Netstubmler does something pretty different. This shows you electromagnetic activity in the WiFi spectrum, no matter what protocol. NetStumbler only shows you things talking the WiFi protocol, but gives you WiFi-specific details. I use both for different purposes.
    • really?

      so show me how to set netstumbler to detect 4.2ghz transmissions that do not have SSID's or wifi Rf protocols.

      netstumbler cant show you the raw RF signal levels at each RF channel for wifi.

  • by Ancient_Hacker ( 751168 ) on Tuesday June 20, 2006 @11:40AM (#15569689)
    There's these things called the laws of econoics and physics which make it unlikely to duplicate the spcs of a $4000 specrum analyzer for $100.

    Now Idon't know exactly what they put in that little USB pod, but it's unlikely it has the expensive dual-conversion superheterodyne signal chain, the interdigital varactor tunable filters, the low-noise Gallium-arsenide preamps, and the other expensive features of a real spectrum analyzer.

    These cheap ones *may* be *mildly* useful, under *some* conditions, at *some* temperatures, and in *some* environmnts*. But usually the times we really need one of these eexpensive beasties is when all the conditions are unsuitable for the cheapo ones.

    For example, just leaving out the tricky filters means the cheapo device will be very sensitive to other, out of band signals, that are of no consequence. False positives, very bad thing to see when you're trying to impress the client. Even worse when they pay big bucks to relocate the interfering devices, and the network still doesnt work.

    • by maelstrom ( 638 ) on Tuesday June 20, 2006 @11:58AM (#15569817) Homepage Journal
      "Now Idon't know exactly what they put in that little USB pod, but it's unlikely it has the expensive dual-conversion superheterodyne signal chain, the interdigital varactor tunable filters, the low-noise Gallium-arsenide preamps, and the other expensive features of a real spectrum analyzer."


    • Um, I don't think anyone was suggesting using one of these in a commercial setting. Particularly as a tool for use by an RF engineer.

    • These cheap ones *may* be *mildly* useful, under *some* conditions, at *some* temperatures, and in *some* environmnts*

      As they make clear on their home page, it's a $100 tool for debugging $100 networks. Or just for futzing around, really. I have one, and it's a great help in resolving basic questions like, "Is it my cordless phone or a neighbor's?" or "Is my cheapo wireless router dropping the connection because of interference or because it's retarded?" Plus it's neat to wander around any see what's emitti
    • The $100 device may not give you a 'free lunch,' and almost certainly won't hold a candle to a $5000 or $25,000 analyzer, but that doesn't mean it's not worth the money.

      People are comparing this to really expensive professional tools. That's a fine comparison to make, but it's purely academic. I'd like to have a spectrum analyzer -- what geek wouldn't? But I also have a budget, and $5k for a tool I'll only use occasionally isn't in it.

      So really, instead of comparing this thing to tools that the average pers
      • I wish I could agree with you, but I think the opposite is often the case.

        The less you know, the MORE you need a tool that doesnt have lots of glitches. p> If you're a PhD EE, then you already know all about image and harmonic and third-level intermod products. So when you see a strange blip on the radar, you go "of course, I'll ignore that, it's obviously the second harmonic of TV channel 41 minus the neighbor's baby monitor."

        If you're a noob, you may end up chasing all over the neighborhood looki

        • Did you really miss the point of the original poster? The comparisons to $5000 devices are irrelevent, since the people buying this thing can't possibly afford a $5000 device. What you should be comparing too is having no spectrum analyzer at all. If you go into some small business and notice a lot of interferrence on channel 1, move them to channel 6. If turn on the old microwave and see a huge amount of noise across the spectrum, tell them to buy a new microwave that generates less interferrence.

  • by llZENll ( 545605 ) on Tuesday June 20, 2006 @11:48AM (#15569742) []

    And from the review if you can't load it:


    The 2.4 GHz spectrum is unlicensed. This means anyone can throw any type of signal they want into it. Anything from wireless AP's, to home automation products, to everyday appliances will throw out signals in this radio frequency. What all this means to the average person is this... interference. Either interference from other AP's, or a microwave, or a cordless phone. Either way, multiple devices vying for the same spectrum can never be good; it will affect your signal and degrade your throughput. The way to deal with this type of interference is to either ignore it, or try to go around it. Ignoring it might be acceptable for some, but finding ways around it is really a hit or miss proposition. It is hard to work around something you can't see. Sure, changing the channel on the router or physically moving the device might work, but in the end, you are just guessing. Now you no longer have to guess. With the introduction of the Wi-Spy, you can "see" the interference you are trying so hard to avoid. Before, you might have gotten the channel or the position right and enjoyed a cleaner signal, but I doubt that happened quickly. With the Wi-Spy, you should be able to figure out quickly and definitively just what your monkeying around might have eventually revealed. If anything, being able to rule out what won't work, you have won half the battle. With all the time you save, you can finally get out and do more important things like mow the lawn or clean the kitchen. (Ed: Oh goody!)

    You just can't beat being able to "see" the spectrum you are using. Not having to take out a personal loan to buy the equipment is another plus. The software may have its quirks here and there, but no matter what, it still provides a good view of the spectrum you will be attempting to navigate. Software can be upgraded and fixed, and I believe that as time goes by, it will only get better. Considering its competition, the Wi-Spy is a steal at $100. If you do any type of wireless network setups, or you get drafted to set up everyone else's, the Wi-Spy should most definitely be in your laptop bag.

    If you'd like to purchase the MetaGeek Wi-Spy, you can get it for about $100 directly through or you can buy it at


    A spectrum Analyzer on the cheap
    Easy to use
    Did I mention it wasn't $3000+


    Software could use some tweaking
    Requires .NET 2.0 to run
    Only works on 802.11b and g, not 802.11a
    • by Anonymous Coward
      Actually, there ARE licensed users of the 2.4GHz band !

      They're radio amateurs, and in the USA, they're licensed by the FCC, and their rules
      are found in Part 97 of the FCC Rules and Regulations (47 CFR 97).

      They're allowed to run up to 1500W output power into as big an antenna as they can afford,
      although they are only allowed 100W on spread-spectrum.

      They do not have to suffer from interference by unlicensed signals operating under the aegis
      of FCC Part 15 (47 CFR 15); unlicensed operations must defer to licens
  • EM camera (Score:3, Interesting)

    by yancey ( 136972 ) on Tuesday June 20, 2006 @11:55AM (#15569792)
    What I've wanted for a long time is an "EM camera" where I could "see" sources of electromagnetic radiation in real-time, something like a modern digital camera with an LCD view screen. We've got cameras for EM in the light range, but why not for other frequencies (higher or lower)? For example, I want to point this camera at an EM source like a microwave dish and see it sending out a beam like the headlamp on a car. I'm not saying it's practical. I just want one. If you could do this at low enough frequencies, you might be able to detect radio transmissions at a distance (say finding someone hiding in foliage across the street and using a FRS/CB/amatuer radio).
    • We call this "passive radar", dude. You only see a "beam" of light from a headlamp if there's dust or fog to scatter the light. Otherwise you see a spot of light, just like what you see on your radar scope. If you "shone" your microwave beam through a cloud of iron filings, you'd probably see something remarkably akin to your headlamp-beam-through-fog.
    • Re:EM camera (Score:1, Interesting)

      by Anonymous Coward
      That sort of thing is called an antenna. You probably want something like an array of highly directional ones, parabolicals for example. Unfortunately the "picture" you will get hardly qualifies as a picture, as the finest details you will be able to resolve will be about half the wavelength of your radiation - for example in case of CB 5.5 meter (!).

      Also your perception of visible beams is not very realistic as those frequencies do not scatter to much on plain air.
  • As noted in TFA (page 4), the product is carried [] by Thinkgeek [], which like Slashdot [], is owned by OSTG [].

  • by wramsdel ( 463149 ) on Tuesday June 20, 2006 @12:05PM (#15569887)
    I bought one of these...neat toy. The hardware is nothing special, it appears to be a Cypress WUSB reference design manufactured by Unigen []. The firmware may have been modded a bit...if for no other reason than to change the USB strings (or not, I can't remember how it enumerates.) At any rate, I'm going to bet that they just look at RSSI across the band and report it back in a meaningful way. Clever use of the technology.

    As many other readers point out, a spectrum analyzer it's not. I really don't think that's the intended purpose. It gives you an indication of band occupancy over time, and that's about it. For many uses that's just fine. If I'm trying to get some ISM-band device to form a link and it won't, the WiSpy gives a good first-order indication of band conditions. If WiSpy comes back clean, I move on to other diagnostic steps, generally involving test gear that costs (easily) 100 times what the WiSpy did. If it saves you some time, great. In my opinion, it's cheap insurance.
  • by scharkalvin ( 72228 ) on Tuesday June 20, 2006 @12:17PM (#15570008) Homepage
    It's not a spectrum analyzer, but it is a nice panaramic receiver.
    The difference between the two is resolution. A panaramic receiver is just
    a band scanner. It will tell you what channels are occupied and the relative
    signal strength. A spectrum analyzer will do the same and more, such as
    giving you a good idea of the kind of signal you are looking at, and it's
    purity. Many years ago Hams used panaramic receivers (scope display) to
    see where the dx and band openings were without having to tune from one
    end of the band to the other. If you are looking for a clear (or occupied)
    channel the panaramic receiver is good enough. If you want to know why the
    FCC cited you for a dirty signal, then you want a spectrum analyzer.
  • My wireless card software can already show me the signal-to-noise levels on all the channels so I fail to see what else that thing can do in addition. And if you insist on seeing a quite useless image of the 'spectrum' then there are free software for that out there already such as Kismet [].

    The comparison on their website is just silly. You can rent a basic spectrum analyser [] for a couple of hundred dollars for the day, plug in a directional antenna to your test port and pinpoint your problem, as well as use

  • No, thanks.... (Score:5, Interesting)

    by Doctor Memory ( 6336 ) on Tuesday June 20, 2006 @12:42PM (#15570232)
    ...I prefer to roll my own []... Granted, it's only 250KHz of resolution (although you can change the filter, not sure how narrow you can get), but it's enough to get you started. I'm also seeing references to SA front-ends made from old TV IF strips. With lots of people upgrading their TVs, I expect to see a lot of these IF strips available.
  • by RebornData ( 25811 ) on Tuesday June 20, 2006 @12:46PM (#15570263)
    I'm a small office / home office IT consultant, and I bought one of these a few weeks ago after stumbling across it on ThinkGeek. It's fabulous for my needs, which are simple: figure out if interference is the reason someone's wireless network is flaky.

    Wi-Spy does a great job of doing this. I fired it up at a downtown client and saw there was a strip of intense interference down in channel 1. Moved them up to 11- problem solved. I've also done some tests at home... it's very easy to tell the difference between a microwave, spread spectrum phone system, video sender, and other wifi networks... they have rather distinctive appearences in the graphs Wi-Spy produces. Now that I know what they look like, I can take an educated guess, where before, I was grasping at straws.

    For those of you getting your panties in a wad about it not matching a $5000 spectrum analyzer: Duh? Of course it doesn't. But that doesn't mean it's useless... there are a lot of folks (like me) for whom the cost of a "real" spectrum analyzer is completely unjustifiable. But I can spend $100 easily, and *for what I do*, which is occasionally troubleshoot SOHO wireless networks, it provides most of the functionality I need.

    The really interesting fact is that this thing defines an entirely new product category: inexpensive spectrum analyzers. I would really like to see what could be done for $500... that's still an order of magnitude cheaper than the existing solutions, but I bet you could add a bunch of features.


  • Another review (Score:3, Interesting)

    by mrhandstand ( 233183 ) on Tuesday June 20, 2006 @12:49PM (#15570283) Journal
    I wote a review for last month, and I did review the OS X third party software...which is MUCH nicer than the stock stuff. Reg required, but its a decent review. As for picking up picked up my headset just fine.
  • the fact that this requires .NET 2.0 does that mean that it would potentially work on linux with Mono?
    • Re:mono? (Score:3, Informative)

      by Ryanwoodings ( 60314 )
      There is already a separate Linux app that has most of the functionality of the Windows app. I suggest using that versio (available from []) instead of trying to get the Windows app running under Mono. The reason for this is that the USB library used by the Windows app, probably will not work under Mono.
  • I don't know a lot about van Ecking, but could a device like this be hacked to spy on people?
  • Circuit Cellar (Score:1, Informative)

    by Anonymous Coward
    Circuit Cellar published an article on how to build one of these a few months back, I wouldn't be surprised if it was exactly the same hardware. The circuit cellar version costs a fraction of the cost to build yourself mitage-189/index.htm []
  • by MindPrison ( 864299 ) on Tuesday June 20, 2006 @05:09PM (#15572311) Journal
    ...fiddling with my HP8590 spectrum analyzer bought via the internet....

    You can keep your 100 Dollar wifi-thingy

    My baby can do so much stuff the owners of a 100 Dollar wifi-spy can dream about
    It can scan everything realtime (I do mean REAL-TIME) oh...and did I mention it can scan
    the WHOLE darn spectrum...not just the Wi-Fi spectrum? And's still realtime
    and it's from the 80's and didn't cost an arm and a leg.

    I'd say it's better with a 1000 Dollars worth of real results rather than 100 dollars of promises!

    /Me *hugs* his REAL spectrum analyzer ;)
  • Ok sure, it's a spectrum analyzer, but it only does a couple hundred mhz. Maybe good for wifi, but it won't be replacing my beloved HP 141T Picture: []. That baby can do 0-18ghz, with the correct plugins. And yes, I do have the correct plugins. And two mainframes. and the external mixer. Oh can replace it with a little USB unit... as soon as you pull it from MY COLD DEAD HANDS!

  • For what the device is I do think it is a bit over priced. From what I was able to put together a JUNO-USB only costs about $6 USD. So as much as I want one I'll wait for the price to come down a bit or for more players to come to the market.

    dirty pdf version []

    google html version SB+usd&hl=en&ct=clnk&cd=1 []

System restarting, wait...