Wireless Spectrum Analyzer on the Cheap

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..."

Comments

Interesting, but...

[evileyetmc]

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.

Just another toy

[wiz31337]

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?

You know...

[jagossel]

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.

No free or even $100 lunch

[Ancient_Hacker]

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.

Re:Wires, baby Wires

[alexburke]

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?

EM camera

[yancey]

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).

Re:EM camera

[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.

Re:Lots of questions unanswered...baited with pric

[Cylix]

I feel I have to chime in here...

You act as if the tools are not necesary for the job.

Next time you have to do something that requires the least amount of precision (due to fines, complaints and general hazards of being wrong) try using the bare minimum equipment or none at all.

The guy was dead on in his assessment and insulting him does nothing to further your point.

So yeah, it's crap, if you want this same functionality... you can go out and buy a wireless repeater and flash it with the "spectrum analyzer" firmware for monitoring. Don't care to look up the name, but I'm sure more then one company offers those options.

Re:Lots of questions unanswered...baited with pric

[Sponge Bath]

$5000 will get you a working HP 8566B on Ebay.

100 Hz to 22 GHz, 10Hz resolution, and if you can lift 100 lbs
you can even call it portable :-)

No, thanks....

[Doctor Memory]

...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.

Another review

[mrhandstand]

I wote a review for labratmagazine.com 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 Bluetooth....it picked up my headset just fine.