To Scan or Not to Scan

To Scan or Not to Scan

Post by Anthony and Alina Jociu » Mon, 26 Jan 1998 04:00:00

Techies,

What is the law on scanners?  I understand that some scanners can
intercept cell phone conversations.  If they do, what is the model
number of the type that do.  Do scanners only pick up local
transmitters?  Can they pickup a transmission 100 miles away?  Does a
scanner listen to the strongest signal then skip when a stronger signal
is received?  Questions, questions, I have no scanner experience, is
there a web site that describes the terms, technologies and sellers?
Are scanners digital or analog receivers?  Do they require special
antennas?

Tony
(So many questions)

 
 
 

To Scan or Not to Scan

Post by allsaf » Mon, 26 Jan 1998 04:00:00



Quote:> Techies,

> What is the law on scanners?  I understand that some scanners can
> intercept cell phone conversations.  If they do, what is the model
> number of the type that do.  Do scanners only pick up local
> transmitters?  Can they pickup a transmission 100 miles away?  Does a
> scanner listen to the strongest signal then skip when a stronger signal
> is received?  Questions, questions, I have no scanner experience, is
> there a web site that describes the terms, technologies and sellers?
> Are scanners digital or analog receivers?  Do they require special
> antennas?

> Tony
> (So many questions)

  ECPA can be *interpreted* to mean that knowingly receiving cell phone
conversations without the consent of the parties talking is illegal.  But
the language is ambiguious.  If you record such conversations, you stand a
greater chance of getting prosecuted than if you just listened (If you get
caught).   If you get a scanner, don't talk to anyone about it.  Don't tell
your neighbors, your co-workers, whatever.  Just keep the scanner and what
you hear to yourself.

Since Late 1994, scanner manufacturers have taken tough steps to make
scanners  with cell phone frequencies blocked and difficult to modify.
Cell phone frequencies were blocked out on many early models, but the block
was easily circumvented by clipping a diode, or soldering in a wire patch,
etc.  Nowadays, the modifications are not that easy.  There's lots of guys
here who could do it.  Not me.

I'm sure someone is going to come along and give you more info.

 
 
 

To Scan or Not to Scan

Post by Rich Well » Tue, 27 Jan 1998 04:00:00


Quote:> What is the law on scanners?

It is perfectly acceptable in most circumstances. There
are states which are scan-phobic(like Kentucky) which
forbid such actions outside of your home. There are
a few states which ban mobile use of scanners. Most
states have laws against using them in a comission of
a crime. Federal laws make it a no-no to listen to
cellular or cordless, to unscramble that which has
been scrambled and other little tidbits.

Quote:> I understand that some scanners can
> intercept cell phone conversations.  If they do, what is the model
> number of the type that do.

Due to federal laws, manufacturers can no longer make
scanners which do this nor can they be easily modifiable
to do so like in the past.

Quote:> Do scanners only pick up local
> transmitters?

Pretty much. Comes down to the performance of the
scanner used, the antenna as well as how high you
can mount it(the higher, the better usually) and
what kind of power the transmitter is putting out.

Quote:> Can they pickup a transmission 100 miles away?

Most scanning is done VHF/UHF where there must be a clear
path between transmitter and your antenna. The curvature
of the earth, as well as other things, obviously limits
this distance. Depending on your elevation and the
height of the receiving antenna, you can work towards
100 miles but in normal use you're talking 30-50
miles max. An obvious exception is aircraft which are
up so high they can keep a clear path to your antenna
so 200+ miles is possible.

Quote:> Does a
> scanner listen to the strongest signal then skip when a stronger signal
> is received?

Not really. A scanner is usually scanning or searching. While scanning,
it is simply cycling through a programmed set of frequencies to see
if any of them have active transmissions. If they do, it stops to let
you listen to it then resumes when the transmission completes or you
tell it to continue. While searching, it is simply incrementing a
frequency value by discrete steps between a lower and upper limit
you usually select yourself. If an active transmission is found, it
will stop to let you hear it. There are variaions on these themes
but this is a large portion of what they do.

Quote:> Questions, questions, I have no scanner experience, is
> there a web site that describes the terms, technologies and sellers?

Try having a look at my Getting Started page

             http://www.qsl.net/n2mca/STARTING.HTM

as well as my New Scanner User FAQ in my signature. You can also
check out my main radio page at http://www.qsl.net/n2mca/RADIO.HTM
for an overview of the hobby as well.

Quote:> Are scanners digital or analog receivers?

Most communications are still analog while the scanner
itself uses digital synthesis for reception. With special
devices and software, you can receive and decode various
digital streams.

Quote:> Do they require special antennas?

Require, no. Depends on how heavy you get into things.
Scanners come with antennas which connect to the scanner
itself for indoor use. To get more signals, you might
decide to mount an external antenna. And there are
different types of antennas for different purposes
and you can buy ones which are tuned for certain
frequency bands to help you pick up signals better
in these regions(at the expense of reception elsewhere).

Good luck with your introduction and feel free to e-mail
me if I can help further!

Strong signals,
Rich Wells  N2MCA  http://www.qsl.net/n2mca/
New Users FAQ : http://www.qsl.net/n2mca/NEW_USER.HTM