TUCoPS :: Hardware Hacks :: ham07.txt

Radio hacking (part 2)

			      PART II

  This article deals with Satellite hacking, CB info, and car phone

Satellite Control
  Companies try to build satellites to last for as long a time as
possible.  Unfortunately, for the companies, things in space can
happen unexpectantly and suddently.  Take that satellite released by
the space shuttle.  It's orbit carried it way off t he correct
altitude.  The company's only hope was to fire a rocket on it in order
to bring it to the correct place.
  Now think...how does one on the ground fire a rocket in space?
Radio!	Gee, if the company could change the orbit, maybe we can too.
Sound interesting?  Of course we were not the first to think of this.
The satellite companies have worried about this for a long time.
There are stories about top secret codes, frequencies, and protocols
required to 'nudge' one of those babies.
  The only problem is that-there is little information about this out
there.	If you have any info, make a text file, and let others know of
your knowledge.  But let me tell you all I know about a simple
satellite whose telemetry is known well.
  OSCAR 6 was a satellite sent up in order to take in amateur signals
between 145.9 and 146.0 MHz, and re-transmit them between 29.45 and
29.55 MHz using a transponder.	Early in 1976, OSCAR 6 began to have
battery problems.  The telemetry allowed the ground command stations
to shut the satellite off at regular intervals to prolong the useful
life of the satellite.
  Now we know the satellite sent out telemetry reports at a certain
frequency (OSCAR 7 was 29.502 and 145.972 MHz).  And it sent them out
in the form of Morse code at about 20 wpm.  Information rate of spin,
power use, and temperature were sent out at 20 wpm.  This seems to
suggest that the control might have also used morse code.  Strangely
enough, there was never any information in the American Radio Relay
League magazine about just how they control the OSCAR satellites.
(Hams know what's safe and what's crazy also)
  Suggestions:	Don't overlook RTTY when trying to Satelhack
(Satellite hacking).  Also, chances are the owners will figure out
what you did, so 'downing', the ultimate for a satelhack, is pretty

Citizen's Band
  CB is a very popular communications method.  Again, you need a
license from the FCC to operate legally.  But it's so hard to track
down a CB signal unless you have a massive amplifier or talk for hours
straight, there is little use in getting one.  Here is a list of
channel frequencies:

Channel 		Frequency
   1			 26.965
   2			 26.975
   3			 26.985
   4			 27.005
   5			 27.015
   6			 27.025
   7			 27.035
   8			 27.055
   9-emergency		 27.065
  10			 27.075
  11-contact channel	 27.085
  12			 27.105
  13			 27.115
  14			 27.125
  15			 27.135
  16			 27.155
  17			 27.165
  18			 27.175
  19-trucker's channel   27.185
  20			 27.205
  21			 27.215
  22			 27.225
  22A (optional)	 27.235
  22B (optional)	 27.245
  23			 27.255

A Cheap Ghost-Interferance
  How can you start a real cheap ghost or interferance station?  Well,
the Radio Shack wireless FM microphone (the clip on one) is pretty
good for $19.95 (price may change).  It's range is said to be 100
yards, but actual tests show its range is about 100 ft.  outside, 40
ft.  inside.  However, in the instructions it says that increasing the
battery power will make it stronger, but this would not be in
compliance with the FCC (oh darn!).  One problem with this is that
with a stronger battery comes the risk of frying something inside.
Instead of trying to upgrade the silly thing, just make a new one.
Open it up and take a look at how it is made.  Now, get a cheap
microphone then feed it into an amplifier like that on your stereo.
Then take the outputs of the amplifier and feed it into the same kind
of circuit as the wireless microphone contains (use heavy-duty parts
so they won't fry.  The only parts are a varactor diode and three
silicon transistors).  You new transmitter can now block out stations
in a relatively sized neighborhood (great in cities).

Mobile Phones
  Radio phones have been around for a while.  The first mobile
telephone call was made September 11, 1946 between a Houston Post and
a St.  Louis Globe reporter.  An old mobile phone service in New York
city had 700 subscribers, but could only handle 12 conversations at a
time (because it had 12 channels).  There are some 160,000 mobile
telephones nationwide.
  The old service was doomed to fail.  Each major city had one or two
powerful transmitters to communicate with all car phones in a 30- to
50-mile radius.  To make a call from a car, you must find a vacant
channel, then call the operator and supply the number you want to
call.  The operator dials the number and connects you when the party
answers.  Only a few companies have dial-it-yourself service.  If
someone wants to call you, they must first find the mobile phone
operator in your area.	The operator finds a vacant channel and
transmits a series of tones that correspond to your phone and make it
ring-sort of as if it were a pager.  Once you answer, the operator
connects you and the caller.
  Clearly, the system was slow.  Worse, it could only serve a few
users at a time.  During rush hour, there was little hope of making a
call.  Few channels could be added because of the dearth of
frequencies for that kind of operation.  So now you can't get a mobile
phone of this type unless someone else gives one up.
  Enter the cellular mobile radio.  Instead of only 1 or 2
transmitters, an area is divided up into many small sections, called
'cells'.  Each has it's own low-powered transmitter just strong enough
to serve it's cell.  An average cell covers from one to eight square
miles and varies in shape from a circle to a squashed football.  Each
cell touches another, some overlap slightly.
  Adjacent cells use different channels-there are more than 600 in
each city to choose from-and a channel may be re-used several times in
the city if the cells are located far enough apart.  All of the cell's
transmitters hook into one network switching office, much like a
central office handles calls form land-based telephones.
  Each transmitter constantly sends out a special signal, and as you
drive from cell to cell, your telephone automaticly tunes in the
strongest cell.  When a call comes in for you, the network switching
office uses the channel to send a digital pulse signal that
corresponds to your ten-digit phone number (NPA+7 digits).
  When the phone hears it's number, it in effect says 'Here I am, in
this certain cell'.  That information is sent back to the network
switching office, which scans vacant frequencies, and relays the
information to your cell.  Finally, your unit tunes to that voice
channel, and the cell site rings you, and you talk.
  It sounds complicated-and it is.  But it works in seconds.  And it
can be expanded.  As more and more phones are added, cells can be
split into smaller cells with less power.  Cellular radio already
exists in Japan, Denmark, Norway, and Sweden.  In Denmark, service
began in 1981 and grew to 100,000 customers almost overnight.  Within
a few years all of Scandinavia will have compatable cellular systems.
Australia, Canada, and Mexico also plan systems.
  Why has the U.S.  lagged behind?  Yep, it's our old freinds, the
FCC.  They studied the system for 12 years before okaying the service
in 1982.  The U.S.  may be full celled by 1988.  Now is the time to
rent your backyard as a cellular station!
  The Bell companies will operate cellular service as the Cellular
Service Company.  Others such as GTE and MCI plan similar service.
Even the Washington Post is trying to get into it.  There are already
two systems, one in Washington/Baltimore, and one in Chicago.  Chicago
users pay about $50 rent and $25 monthly use fee for 120 minutes, and
25 cents/minute hereafter.  Average bills are $150/month.
  The main unit mounts in the trunk, and just the handset sits up
front.	The antennas are very small-about nine inches-and are hidden
inside the car.
  Now freaking old car phone systems shoudln't be that hard if you
really try.  The following are the freq's to remember:

  158.07-158.49 MHz (mobile)
  152.81-153.03 MHz (base stations)

  You CAN listen in on these freq's.  What I'm not sure about is
whether you can place a call-I would think so.	So Freq out!

  COMMING SOON:  Repair trucks, installers, and linesmen, Marine
Radio, and Airplane phones

-the unknown freq
(Formatted by: NEAT DUDE)

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