If they're digital, there's a decent chance that, even if you do find it, it'll just sound like background noise. Also, if your units were advertised as being "spread spectrum," effectively all your scanner will see is a small increase in the noise floor of the entire band and you'll never find it.
The tool you really need is a spectrum analyzer or perhaps a service monitor. :-)
Hi all,
I have a scanner that goes all the way to 2 GHz. I also have a couple of cordless phones. Both Panasonic, one says "900 MHz digital", the other does not have the word "digital" in it. I thought maybe I can find them with the scanner. I could not. Maybe the "digital" is not rally analog so I can understand. I thought I should be able to find the non-digital. I swept the
900 MHz range with no luck. Am I missing something here ? Do they really use 900.000 MHz ? what about modulation (FM, USB,LSB,etc) ?Thanks
Heddy Lamar doesn't want you to.
Off the top of my head, the band is 902 to 928 MHz. Some non-digital ones use several channels of wide band FM at two different (handset, base) frequencies in the band. Digital ones can be either frequency hopping or spread spectrum or a combination of both. A spread spectrum signal would sound like digital hash spread out over some MHz of the band.
Mark Zenier snipped-for-privacy@eskimo.com Washington State resident
Or, they could be in tthe 2.4 Ghz ISM band, whcih isn't covered by your scanner.
Slightly more expensive phones can operate as high as 6 gHz too.
Just a short time ago, 900 Mhz was common....with recent advances in technology, the frequencies have gone up too.
As others pointed out, they could be spread spectrum. If carried to the limits of technology, you would have to put the phone in a shielded room and use a wideband spectrum analyzer to even have a hint of where they are operating in frequnecy.
People that do FCC certification have shielded rooms, just for this purpose.
MDid some ebay checking right afteer I sent the message.
Here's a 5.8 Ghz phone:
and, another one:
'nuff said.
M
If you aren't sure about your particular phone model, and the manufacturer does not have info...
You can search the FCC type acceptance database to get alot of info.
I used it to find technical info on my vlf wireless dog fence manufactured by petsafe. IN my case, there were high res pictures, a full schematic, theory of operation and similar info. It was a goldmine of info and helped me alot.
Regards,
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