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Beginners Guide to Scanning
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SCANNER.DOC
The following is a guide to the hobby of monitoring the
Public Service bands, and some general tips for beginners to
the hobby.
This guide is broken down into 3 parts:
(1) EQUIPMENT
(2) SCANNING TIPS
(3) SECTION 605, ECPA OF 1986, RESPONSIBILTY
EQUIPMENT
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SCANNER TYPES: tunable, crystal, programable
Tunable: Many types of tunable recievers are available to the
scanner user. most of these have poor image rejection and
were low-end units or mutiband type radios. These were
subject to intermod and are only good for a few very strong
signals and local coverage. Poor choice.
Crystal: Crystal-controlled scanners have been around since
the 60's. These radios very from 1 channel to as many as 16
and are very good performers. They allow a set, 1 frequency-
1 channel capability, and have good image rejection and
filtering. These radios allow the first time user to sample
frequencies at relativly low cost per channel, about 5
dollars per crystal.
Crystal controlled recievers are also good for professional
users as the cost is low and most Public Service users only
need to monitor a few set interim channels.
Programable: These are by far the best for the serious
scanner hobbiest. Programable recievers have good S/N
figures, good image rejection, and for the most part very
little intermodulation. They also allow greater flexability
by allowing the user to change channels without spending
money for crystals. Most all of the programable radios have
LED or LCD readouts that give frequency, channel number, and
other user information. All have memory backup to retain the
contents of what has been programed. Programable recievers
are by far the best cost per dollar units.
These radios use to cost 300 to 700 dollars a few years ago
but with computer technology, low IC cost , they now can be
had for a little over 100.00. The main compromise in price
these days for a programable scanner, is channels, frequency
coverage, and special features.
A minimum setup would be 20 channels, and the 118-136 Mhz
aircraft band. 150.00 for this setup.
* Scanner Tips *
Now that the radio is sitting there, how do you know what
frequencies to enter ? Most manuals that come with scanners
have a spectrum breakdown to help new users find a ballpark
area of interest.
Frequency Spectrum Breakdown 30Mhz to 512Mhz
30 to 50 low-band VHF
military,police,fire,business, new cordless phones 46-49mhz
mostly older systems in rural areas,mobile phone(not used in
larger areas.paging systems used extensivly.Subject to long
range skip conditions and solar activity.
50 to 54Mhz Amatuer 6 meter band
54 to 72mhz TV Ch. 2-6
72 to 88Mhz low power industrial
88 to 108Mhz FM Broadcast Band
108 to 136 (AM) Aircraft band,Tower frequencies start at
118.000
136 to 144Mhz land mobile (Military)
144 to 148Mhz Amatuer 2 meter band
148 to 150.600 Mhz military
150.6 to 152Mhz Business
152 to 153Mhz RCC mobile phones and taxi cabs
153 to 154Mhz Public Transportation
154 to 155Mhz fire depts.
155 to 156Mhz State police
156 to 157Mhz Marine Band,ship to coast,ship to ship,Coast
Guard,
Bridges,toll Booths,Locks,inter-coastal waterways.
157 to 158Mhz Marine operations,Coast
Guard.156.800(Distress,Calling)
158 to 160Mhz State Police
160 to 162Mhz Marine phone,various users
162 to 174Mhz Govt. including all agencies
174 to 220Mhz TV Ch.7-14
220 to 225Mhz Amatuer radio
225 to 400Mhz UHF Aircraft (Military),Satelittes,Experimental
Work
400 to 406Mhz Wx Satelittes
406 to 420Mhz Govt land mobile 430 to 440Mhz Fixed
440 to 450Mhz Amatuer 70cm Band
450 to 453Mhz Business, Power co.'s
453 to 454Mhz Local Police Depts.
454 to 455Mhz RCC Mobile Phone
455 to 456Mhz TV News Teams,Rebroadcasts
456 to 458Mhz Public Transport,Business,etc.
458 to 460Mhz Local Police Depts.
460 to 460.5Mhz Local Police Depts.
460.5 to 461Mhz Local Fire Depts.
462 to 463Mhz Business,GMR Service,REACT Teams
463 to 464Mhz Fire Dept. (Med Ch's)
464 to 470Mhz Public Safety,Industrial,Land Transportation
470 to 512Mhz Broadcasting,Shared With Local Public Safety
and other users.
As you can see there is a lot of ground to cover or
monitor.
Antennas: Most of the antennas that come with these
radios are sufficient for local area coverage up to 75 mile
radius from the listening post. If you can put up and
external antenna, your range can be up to 200 miles or more
depending on the antenna type.
External antennas:
Omni: omnidirectional, 360 degree radius
signal pickup.
Yagi: directional, high gain
beam: high gain, highly directional
discone: high gain, wide bandwith, omnidirectional
Your choice of external antennas depends on what
services you are looking to hear most. Beam antennas are good
for long range, single frequency coverage.
Omni's pull in many signals, where discone and yagi's
tend to have higher gain and wider bandwiths. A good
compromise to all these antennas is the Discone, with wide
coverage and good signal puling power.
Once you have your radio and antenna set up, keep in mind
these tips: keep your squelch control at a low theshhold
level, you will hear more. Weak stations can sometimes be
improved by re-orienting your antenna. Use NOAA Wx. stations
for your area, when aligning your antenna or testing. These
stations are continuous broadcast and can gauge
reciever/antenna performance.
Strong carriers can either be real signals or harmonics
caused by other equipment, computers, printers, clocks, TV's,
etc. Reorienting the scanner antenna sometimes will keep
these signal from locking up the scanner. If the area you are
in is really bad, you can buy filters that lock out these
adjacent signals. Some phantom signals are caused by the
radio itself. These are called "intermod" and "birdies",
Intermod is caused by two internally generated signals
causing a third order harmonic that locks up the scanner.
"Birdies are caused by clock and timing signals in
microprocessor controlled radio's, most of these occurr at
only a few frequencies over the entire range of the radio and
can not be locked out. Most makers of scanners have installed
filters to keep this from happening.
SEARCH SCANNING:
Searching for new frequencies with a programable scanner
is accomplished by entering "upper and lower" frequency
limits. A word of note, only enter a 1 megahertz search area.
The reason for this is, the smaller the search area the more
likelyhood of finding new frequencies .I.E 155-156 mhz.
Another tip is to put the delay function on during
search mode. This allows you to note the frequency and also
allows for a reply. When monitoring a transmission, take
notes as to ID codes and or FCC call letters. Most public
service users are required to ID their station at least once
every 5 minutes.
OTHER TIPS:
Inclement weather, storms, major events etc. have a tendency
to increase radio traffic. During storms, monitor local road
crews, rescue services, and other public service bands. The
local officials generally are the people " out in the thick
of it", and you can gleen much info on area road conditions
or detours etc. from this monitoring.
MOBILE INSTALLATIONS:
Check first your local laws covering radios capable of
monitoring police frequencies in a vehicle, before installing
a scanner in your car. The city of Philadephia at one time
had a law making it illegal and a 1st offense punishable by
a 500.00 dollar fine and confiscation of the equipment.
Most radios today have a 12 volt DC negative ground
option or jack for modile use. Once a suitable location and
power requirements are met, all that is left is mounting the
unit and running the antenna. These instructions are
generally included in the owners manual.
**** SECTION 605, ECPA, AND RESPONSIBILITY ****
As a hobbiest, it is important to observe a few rules
pertaining to the scanner hobby. First use of information
overheard via a scanner for personal gain, criminal purposes,
or interference with public safety, is not only illegal but
strongly enforced. Chasing ambulances, fire trucks etc. will
cause you to quickly loose your licence and may get you
arrested. Other responsibilty falls into one important
category: Restraint. If you happen to stumble across a set of
frequencies used by local or federal law enforcement
officials, keep in mind that disclosure of any information
you may hear could interfere with a drug stake-out, hostage
situation, or other life threatening senario.
There are situations where news media people, in their
zeal to cover a story have caused the deaths of hostages
after showing up on a scene after overhearing the operation
on their scanners. Police, Fire and Goverment officials have
jobs to do, and don't need interference from the public. Keep
what you hear to yourself.
The Electronic Communications Privacy Act of 1986
This bill which is currently pass the senate and in the house
of representitives, is a bill designed by the cellular lobby
to restrict what you can and cannot listen to. In it's
present form it makes it illegal to "willfully" monitor any
two-way communication primarily seen as closed to the public.
This includes mobile phone, remote broadcast pickup, and
certain other services, this law is seen by the FCC and the
Justice Dept. as being unenforcable, but as with any bad law
it will no doubt have to be tested in court before it is
reformed or rewritten.
Footnote: Scanning can be and enjoyable hobby and give the
listener a better insight into where his/her tax dollars are
being spent. Public servants are there for helping the people
and enforcing the laws. The United States is the only country
in the world where monitoring is allowed, It is a privilage
that few other countries show their citizens. Be responsible
and enjoy!X-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-X
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