Cell phone scanners

does that mean "law enforcement" as in regular squad cars? The ones that run around here have at least six antennas that are clearly in view. If the cop on the beat had the equipment I suspect that the equipment is relatively available.

Again, we must distinguish between digital and analogue in the above discussion. Apparently Analogue scanners with the capability of receiving

Doesn't seem to far fetched to intercept a digital conversation since all phones have the circuit to do the demodulation and only would need the phone number of the phone being intercepted to weed out other traffic. Sounds as simple as reprogramming a SIM card maybe. . Any way to know if your cell phone is communicating D or A if both are available to you. Can a phone be locked into one or the other mode?

You're the one needs to wake up: Installed Base does not come anywhere near equating to current sales, which still includes both a, d, and duals. If you want privacy, do NOT use a phone of any kind. Oh, and just because YOU have a digital connect, does not mean your called party does. I'd explain further but you're obviously closed minded and not worth the typing.

===> Yes, it does. Some of those antenna's are for duplex operation vs. one way, and others are shared systems for other depts such as fire, rescue, air, rescue, and so on. Many of the latest systems on the market won't even had a visible antenna. There's a plethora of variables in what they can have, including fully computerized systems where channel availability is controlled by the "base" stations or the one in the area they're connected to.

===> Yes, they are, and they're cheaper for the most part because of the age of the technology. Then there is quite an installed base out there already in place.

===> Not sure what you mean by all phones have the circuit to do the demod, but no, that's not true as I intepret your comment. Digital opens up so many new possibilities and is not "demodulated" anything like an analog signal. But, at this point, ANY phone, digital or analog must, by federallaw, be capable of being intercepted, just as any encryption used must be known and allowed by federal requirements. Even with all that, EVERY phone, line or cell, analog or digital, must by its very nature pass through equipment that creates an interception point by the unscrupolous, any anyone with the right equipment can intercept any phone call if they know the technology used in making the call. Many people don't realize either that a digital call originated in say Chgo may go back and forth from digital to analog to digital etc., as it routes to its destination. I made a mistake in my earlier post, too: Feds et al when tapping, can "listen" to any or all of the calls they can find, but they can only "record" relevant phone calls. If the conversation goes off topic for too long, they must pause or cease recording if what they're getting isn't "on topic" for the court order. It doesn't matter what phone you use; just never consider it totally private because it isn't. Digital taps are definitely more complex equipment wise, and it keeps a lot of companies in business in North America and Europe.

Pop

Do you mean to say that for example, my new Verizon digital cell phone can be easily monitored by my neighbor, especially if he is a firefighter?

The federal code applies to interstate calls, doesn't it?

"If my call is going to a land line phone, it is decoded into speech at

the repeater and broadcast over land lines as voice data. The scanner does not pick up the land line signal, therefore can not listen in. "

Cell phone systems do not use "repeaters." as they aren't repeating anything. They use cell sites which serve as the interface between the wireless system and the land based system. For most calls handled today, the entire process is a digital one. It's digital from the cell phone to the cell phone site and it's also digital on it's journey across land lines.

"The older cell phones, like the one my wife has, are still analog. A scanner CAN recieve and play that as voice over the speaker. Her phone

is not secure."

Most cell phones in use today are already digital. Most carriers have moved their customers to digital phones by offering plans that offer benefits like better coverage, lower prices, etc. that are only avail if you have a digital phone. And none of these phones are secure either. It's true that these calls are harder to listen in on, but nothing is being done to specifically encrypt the signal to make it secure. The signal processing is done with the intent of cramming as many calls into the bandwith as possible. A side benefit is that a different receiver would be needed to listen in, but nothing is there to specifically encrypt it for security, which is what would be required to make it secure.

I have a female friend that has come to think her digital cell phone calls are being intercepted by her ex who is a fireman and whose near relative lives within just a few feet away.

Anyway to stop this or at least detect it for sure?

Is equipment necessary to do this readily available or easy for a ham radio enthusiast to modify?

Detect it? Heck no.

I'm going to hazard a wild, naive, outlandish guess... but I would suppose that maybe the fairly sophisticated equiptment you'd need to intercept and decode digital cell calls is NOT being handed out to all firemen. And their relatives.

Of course, her fireman ex's near relative living on her porch does not help.

But now really -- eavesdropping is quite easy, esp. living so close. You can buy cheap directional microphones that listen in at pretty amazing ranges. If you know where to look, you can build or buy cheap equiptment that can listen through windows, etc, too. And listening in on your neighbors like this would all be illegal.

-K