Wi-Spy Spectrum Analyzer

Jeff Liebermann · 2006-01-02T01:45:33+00:00

I've been playing with a Wi-Spy Spectrum Analyzer for a few hours. $99 plus shipping. I installed it on my Panasonic M34 laptop runningW2K and did some really crude testing. Some initial comments:1. It's fairly fast which is a BIG plus. It's much faster and betterthan my Proxim 7400 card. I set my access point to beacon once everysecond instead of the usual 10 times per second. It was easilydetected but took a few sweeps for wi-spy to coincidentally end up onthe same exact frequency as the access point. One can't see thesinx/x DSSS spectra, but it's close enough.2. It can easily pickup my Panasonic KX-TG2257 2.4GHz cordless phoneand microwave oven from anywhere in the house (2 floors). Sensitivity,even with the tiny antenna, is quite impressive.3. Dynamic range sucks but that's understandable. The noise floor isabout -60dBm while the SA saturates at about -32dBm. That's 28dB ofdynamic range which is really bad compared to my ancient HP140Tspectrum analyzer with about 60dB of dynamic range. However, I wouldnot expect much more from such a unit. What this means is that therewill need to be some form of attenuator to deal with close insniffing, and possibly an adjustable gain amplifier for long rangework.I can just barely see my neighbors client radio at about 200ft with a2dBi antenna and a tangle of wet trees in between. I'm sure that withan external antenna on the wi-spy, it would be detectable.I had my neighbor across the street (about 50ft) fire up their Unidensomething 2.4GHz cordless phone. I could see it, but just barely.Again, more antenna gain would be helpful.4. The software appears to be stable and quite useful. Whomeverwrote it apparently has used commercial spectrum analyzers. I hadsome problems restarting the application after hibernation, but areboot solved that. I can run my Netgear WG511v2 PCMCIA card at thesame time. It makes for an interesting display, especially when thecard is scanning for access points.5. I won't post any AVI...

Jan 02, 2006 27 Replies

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William P.N. Smith 20 years ago

Yeah, but as Jeff discovered, they didn't even have to design or build their own hardware, just load special firmware into an existing cordless mouse dongle, and slap on their won plastic cover. Nice, elegant hack, IMHO.

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danr_18 20 years ago

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danr_18 20 years ago

They say that they will probably update their hardware to support an external antenna by this summer.

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danr_18 20 years ago

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metageek 20 years ago

There was a bug in the software causing the spectrograph to only show

1/5 the incoming data; this has been fixed and an update posted. I think that should show more color.

There are no firmware upgrades yet :-)

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Moe Trin 20 years ago

I haven't priced connectors in production quantities in years, but there wasn't that big a price break. Even the cheapest crap connector is going to be a dollar, and after installation, retail mark-up, and profit for the retailer, that's anywhere from 5 to 10 bucks added in the retail cost.

I'll agree with that. I am waiting to hear more testing results from Jeff.

Old guy

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William P.N. Smith 20 years ago

Yeah, strangely, a thread on their forums asking about just that points back here to Usenet.

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How's that for circular referencing? 8*)

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William P.N. Smith 20 years ago

Much better, thanks!

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