[sci.electronics] I listen to cellular traffic on my VCR !

steelie@bucsf.bu.edu (James Howard) (03/21/91)

 I was messing around with my RCA Stereo VCR the other day, and noticed
I could use the fine tuning channel selector to literally tune the
entire range of frequencies that the TV channels are located in.  And I
mean tune them _finely_.    Anyway, I realized after stumbling upon
the MBTA traffic (Bostons subway) that I needed to get the AM portion
of the information, since TV's audio is FM.  So I took the video out of
my VCR and connected it to my amplifier.   Lo and behold, suddenly I could
tune to most airport traffic, subway traffic, and yes, local cellular phone
traffic.
 
I assume I'm probably not supposed to be listening to other people's 
telephone calls.
 
Has anyone ever tried this before?   Just be warned that when you have
the "video out" plugged into your amp and you stumble across an actual
video signal, your ears will get blasted away if you dont have the 
volume turned WAY down.

-------------------------------------------------------------------------
steelie@bucsf.bu.edu
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ahill@hpdmd48.boi.hp.com (Andy Hill) (03/23/91)

>I assume I'm probably not supposed to be listening to other people's 
> telephone calls.
>  
>

Maybe not ethically, but recent court cases (involving bugging/listening in
on cordless telephones) have essentially ruled that once it's been
broadcast onto the airwaves (as opposed to sent down a wire/cable), it's
fair game for reception.  Taking your typical scanner and listening in
on the neighbor's cordless phone is sure to give you voyeurs out there
hours of fun...

                Andy Hill
                LaserJets 'R' Us

mcovingt@athena.cs.uga.edu (Michael A. Covington) (03/23/91)

In article <970022@hpdmd48.boi.hp.com> ahill@hpdmd48.boi.hp.com (Andy Hill) writes:
>>I assume I'm probably not supposed to be listening to other people's 
>> telephone calls.
>
>Maybe not ethically, but recent court cases (involving bugging/listening in
>on cordless telephones) have essentially ruled that once it's been
>broadcast onto the airwaves (as opposed to sent down a wire/cable), it's
>fair game for reception.  Taking your typical scanner and listening in
>on the neighbor's cordless phone is sure to give you voyeurs out there
>hours of fun...
>
   Ah, but CORDLESS phones (with shared frequencies) and
   CELLULAR phones (with computer-assigned frequencies that
   are supposed to give a "reasonable expectation of privacy")
   are, legally, totally different beasts. Cellular phone
   listening is illegal under the Electronic Communications
   Privacy Act (ECPA) of 1986. But, nonetheless, perfectly
   possible on VCRs and UHF TVs, or so I'm told.


-- 
-------------------------------------------------------
Michael A. Covington | Artificial Intelligence Programs
The University of Georgia  |  Athens, GA 30602   U.S.A.
-------------------------------------------------------

frankb@hpsad.HP.COM (Frank Ball) (03/26/91)

* I was messing around with my RCA Stereo VCR the other day, and noticed
*I could use the fine tuning channel selector to literally tune the
*entire range of frequencies that the TV channels are located in.  And I
*mean tune them _finely_.    Anyway, I realized after stumbling upon
*the MBTA traffic (Bostons subway) that I needed to get the AM portion
*of the information, since TV's audio is FM.  So I took the video out of
*my VCR and connected it to my amplifier.   Lo and behold, suddenly I could
*tune to most airport traffic, subway traffic, and yes, local cellular phone
*traffic.
* 
*I assume I'm probably not supposed to be listening to other people's 
*telephone calls.

The FM band is just above channel 6.  Channel 6 can be picked up on
an FM radio also.

Cellular radio is what used to be UHF channels 70 thru 81 or 83 (whatever
it went up to).  These were re-allocated for cellular radio.  

You can only get 1/2 of the conversation, since they transmit and receive
on different frequencies.

Frank Ball   frankb@hpsad.HP.COM   pyramid!hplabs!hpsad!frankb

wtm@uhura.neoucom.EDU (Bill Mayhew) (03/27/91)

I had noticed several years ago on a trip to the TV/appliance store
that all the new TV sets only went upt to channel 63 on standard
antenna input while my old set at home went up to 83.  The reson
for the change became obvious when I noticed that it is possible to
hear fragments of cellular phone conversations in the tuning region
that used to be occupied by the higher numbered channels.  The
older sets that that use a mechanical air capacitor and perhaps an
infamous 1N34 crystal detector a handy for their easily adjusted
continuous coverage.

Bill

-- 
Bill Mayhew      NEOUCOM Computer Services Department
Rootstown, OH  44272-9995  USA    phone: 216-325-2511
wtm@uhura.neoucom.edu   ....!uunet!aablue!neoucom!wtm
via internet: (140.220.001.001)

davet@tsdiag.ccur.com (Dave Tiller N2KAU) (03/28/91)

In article <1840041@hpsad.HP.COM> frankb@hpsad.HP.COM (Frank Ball) writes:
-Cellular radio is what used to be UHF channels 70 thru 81 or 83 (whatever
-it went up to).  These were re-allocated for cellular radio.  
-You can only get 1/2 of the conversation, since they transmit and receive
-on different frequencies.

One can get the whole conversation, so I'm told, by listening to the 
output of the cell site, not the mobile phone itself. The mobile phone
and cell site transmit in two different bands, affording full duplex.
The cell site 'repeats' what it hears from the mobile phone, along with
the incoming phoneline audio.
-- 
David E. Tiller         davet@tsdiag.ccur.com  | Concurrent Computer Corp.
FAX:  201-870-5952      Ph: (201) 870-4119 (w) | 2 Crescent Place, M/S 117
UUCP: ucbvax!rutgers!petsd!tsdiag!davet        | Oceanport NJ, 07757
ICBM: 40 16' 52" N      73 59' 00" W           | N2KAU @ NN2Z

root@alw.nih.gov ((Operator)) (03/28/91)

In article <970022@hpdmd48.boi.hp.com>, ahill@hpdmd48.boi.hp.com (Andy Hill) writes:
|> >I assume I'm probably not supposed to be listening to other people's 
|> > telephone calls.
|> >  
|> >
|> 
|> Maybe not ethically, but recent court cases (involving bugging/listening in
|> on cordless telephones) have essentially ruled that once it's been
|> broadcast onto the airwaves (as opposed to sent down a wire/cable), it's
|> fair game for reception.  Taking your typical scanner and listening in
|> on the neighbor's cordless phone is sure to give you voyeurs out there
|> hours of fun...
|> 
|>                 Andy Hill
|>                 LaserJets 'R' Us

what does that say for "listening in" on "cable" that's broadcast either
by conventional (on the air) means or from a satellite?  
-- 

	jy 
	young@alw.nih.gov

phillips@fozzie.nrl.navy.mil (Lee Phillips) (03/29/91)

To clarify: cordless phones are unprotected, legally.  The police
are even allowed to listen in and use the information as evidence,
without a warrant.  However, a federal law called the ECPA protects
cellular phone transmissions: it is actually illegal to listen
to these, using your TV or a scanner.  If you are thinking that
this doesn't make sense, you are applying the wrong kind of 
sense.  Don't think physical reality, think (legislators +
industrial lobbying).
--
                                           Lee Phillips
                                           phillips@fozzie.nrl.navy.mil
                                           phillips@cmf.nrl.navy.mil
                                           phillips@lcp.nrl.navy.mil

depolo@eniac.seas.upenn.edu (Jeff DePolo) (03/29/91)

In article <1840041@hpsad.HP.COM> frankb@hpsad.HP.COM (Frank Ball) writes:
>Cellular radio is what used to be UHF channels 70 thru 81 or 83 (whatever
>it went up to).  These were re-allocated for cellular radio.  
>
>You can only get 1/2 of the conversation, since they transmit and receive
>on different frequencies.

If you monitor the mobile side, you will have a hard time hearing
anything, unless it's very close.  A couple of watts on 800 MHz from
a mobile station doesn't give you very much range without a dedicated
800 MHz outdoor antenna, such as a beam or a vertical colinear.

If you monitor the "base" side (the cell site), you will hear the landline
party at full volume, and the mobile station partially muted (probably
about 10-20 dB down in most cases).  Both sides are usually completely
understandable, however.

								--- Jeff

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