Introduction to Scanning
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Last changed: October 14, 1994 |
Introduction to Scanning
by Bob Parnass, AJ9S
[NOTE: This article may not be reproduced in whole or in
part on CDROMS, in bulletin boards, networks, or
publications which charge for service without permission of
the author. Free distribution is encouraged.]
This introduction is intended for people new to the
scanning hobby and is oriented to scanning in the USA. It
tells where you can buy your first scanner, what features
it should have, where to get it repaired if required, how
to get frequency information, and mentions a few scanner
clubs worth joining.
Why Scanning?
Every day and night, scanner hobbyists are entertained by
what they overhear on their radios. Police cars, fire
engines, ambulances, armored cars, trains, taxis,
airplanes, and buses are all equipped with radios and you
can listen to them. You can monitor the local sheriff and
fire departments to hear about events "as they happen,"
before the news reporters hear about them. Hostage dramas,
bank robberies, car crashes, chemical spills, tornado
sightings are all fair game. In a single afternoon, you
can hear a high speed police chase, Drug Enforcement agents
on a sting operation, and undercover FBI agents as they
stakeout a suspect.
How about listening to a presidential candidate discuss
strategy with his advisor from a 415 MHz radiophone in Air
Force 1, or a team of G-men protect him while transmitting
in the 167 MHz range?
Listen in the 46.61 - 49.97 MHz range to your neighbors
deal drugs over their cordless telephone, or as their
conversations are picked up and transmitted over the
airwaves between 49.67 and 49.99 MHz by their sensitive
baby monitor intercom.
Stay ahead of road conditions by listening to highway road
crews, snow plows, and traffic helicopter pilots.
Take your scanner to sporting events and listen to race car
drivers, football coaches, etc., in the 151, 154, and 468
MHz ranges.
Monitor the everyday hustle and bustle of businesses, from
cable TV repair crews tracking down pirate descrambler
boxes, to security guards at your nuclear power plant or
mall security guards chasing a shoplifter.
You can even listen to the order taker's wireless
microphone at the local McDonald's restaurant on 154.6 and
35.02 MHz!
Is Scanning Legal?
In the United States, scanning from your home or at work is
perfectly legal in most situations. The Electronic
Communications Privacy Act of 1986 made it illegal to
listen to mobile phones, common carrier paging, and a few
other types of communication, but many scanners cover these
frequencies, and it's clear that Americans still listen to
whatever they want in the privacy of their own homes
despite the ECPA. A new law threatens to outlaw listening |
to cordless phones, too. |
It is now illegal for companies to sell recently |
manufactured scanners which cover or can be easily modified
to cover the cellular phone frequencies, but sales by
private individuals will still be allowed.
Speaking of privacy, federal law also requires you to keep
what you hear to yourself and not use the information you
hear on your scanner for personal gain.
Be aware that several states have laws pertaining to
scanning while in your car. Indiana restricts some
portable scanners. A few states have enacted their own |
laws against listening to cordless phones. You can find
out about these restrictions in a 39 page paperback, ANARC
Guide to U. S. Monitoring Laws, compiled by Frank
Terranella, available for $7.50 from ANARC Publications,
P.O. Box 462, Northfield, MN 55057.
What Scanner Should I Buy?
Radio Shack and Uniden (maker of Bearcat, Regency, and
Cobra brands) offer a wide choice of scanners. Radio Shack
scanners bear the Realistic label but are actually
manufactured by both GRE (General Research Electronics) and
by Uniden. Personally, I don't recommend many of the AOR
brand scanners.
Programmable (synthesized) units have replaced crystal
controlled models as they don't require crystals and
usually have a keypad that permits you to store frequencies
into channels. Programmables are now so cheap it doesn't
make sense to buy a crystal unit as your main scanner
unless you get it for under $45 or so.
You can get a battery operated hand held scanner, a bigger
"base" scanner which is powered from an AC outlet, or a
mobile scanner which connects to your auto's electrical
system. There are tradeoffs -- base and mobile scanners
almost always provide more audio than portables, and
portables are usually more prone to interference when
connected to outdoor antennas than base models. But when
severe weather knocks out the power in your home, there's
nothing like having a battery operated scanner to monitor
the power utility and police frequencies!
Make sure your first scanner:
1. has a "search" feature, which allows it to search all
the frequencies between two frequency limits of your
choosing. The lowest cost programmables can't search.
2. covers the 800 MHz band. Usage of the 800 - 950 MHz |
band is growing fast and you will miss out on the
action unless your scanner covers this band.
If you're not sure whether you'll like scanning, don't want
to spend much money, a 16 channel radio will do. In
general, the more channels and banks, the better.
Most of the action takes place on frequencies between 30
and 1000 MHz, so don't be misled by scanner models boasting
coverage from 3 to 2000 MHz. There's currently not much to
monitor in the 1000 - 2000 MHz range.
If you are interested in receiving short wave, that is,
signals in the 3 - 30 MHz range, it's best to get a short
wave radio specifically designed for that purpose.
Although some scanners receive the short wave band, their
performance in that range is often poor.
Deluxe scanners can be controlled by a personal computer,
although this feature isn't important to many scanner
owners.
Currently, the more popular scanners include the
Uniden/Bearcat 760XLT (a/k/a 950XLT) and Radio Shack PRO-
2006 base/mobiles, and the Uniden/Bearcat 200XLT (a/k/a
205XLT) and Radio Shack PRO-43 portables. A number of
owners report problems with the Uniden/Bearcat 8500XLT and
2500XLT and new replacement models are rumored. |
Considered by many as the best scanner ever made, the 400 |
channel Radio Shack PRO-2006 has recently been replaced by |
the 1000 channel PRO-2035.
Scanner Antennas
All scanners come with a built in antenna, permitting
reception up to about 20 miles or so. Outdoor antennas,
like the Channel Master 5094A or Antenna Specialists AV-
801, can extend reliable reception to 100 miles or more.
If you do use an outdoor antenna, be sure to disconnect and
ground it during storms and when not in use to avoid a
lightning hazard. Discone and ground plane type antennas
can be somewhat more prone to lightning strikes because
they are not at "DC ground."
Where Can I Buy A Scanner?
Almost every community has at least one Radio Shack store,
and you can find scanners there. Discount chain stores
like Wal-Mart, K-Mart, Service Merchandise, and Circuit
City sell scanners, but carry just a few models.
Department stores, like Sears Roebuck and Montgomery Wards,
sometimes offer low end scanners, although at high prices.
The best buys on new scanners are from reputable mail order
radio dealers, for example:
- Grove Enterprises, 300 S. Highway 64 West, Brasstown,
NC 28902. For a free catalog, call (704)837-9200.
- National Tower Company, PO Box 15417, Shawnee Mission,
KS 66215. Telephone (913)888-8864.
- Marymac Distributing (Katy, TX) sells Radio Shack
scanners at discount, but charges a 20% restocking fee
for returned merchandise. Telephone (800)231-3680 and
(713)392-0747.
- Scanner World (Albany, NY). Telephone (518)436-9606.
Beware of inflated "shipping and handling" charges and be
sure to include these when comparison shopping.
Many ham radio dealers, like Amateur Electronics Supply
(Milwaukee, WI, (800)558-0411), also sell scanners.
Used scanners may be found at hamfests, flea markets,
garage sales, or listed in the classified advertisement
section of your newspaper.
Modifying Your Scanner
If you are handy with a soldering iron, you may be
interested in modifying your scanner to add features or
enhance its performance. Be warned this usually voids your
warranty. Modification article files can be copied from
several ftp sites including the /pub/ham-radio/mods
directory at:
ftp.cs.buffalo.edu
garfield.catt.ncsu.edu
oak.oakland.edu (IP address 141.210.10.117)
KD4MOJ maintains a scanner modification server for people
without FTP access. You can request a list of scanner
modifications by sending electronic mail with the words GET
INDEX.TXT to FTP...@exchange.tlh.fl.us
Scanner Repair Shops
Is your scanner broken? Aside from sending the scanner
back to the manufacturer for repair, here are least two
companies which repair scanners:
1. Electronic Repair Centers (telephone 708-455-5105) -
Several people have been pleased with good repair
service from Electronic Repair Centers in Franklin
Park, Illinois. Although they are not authorized to
perform warranty work, this outfit has been repairing
Bearcat scanners for several years. They charge a
flat rate of fixing scanners, and shipping is extra.
Electronic Repair Centers will fix Regency scanners
if they can obtain the parts.
2. G & G Communications (telephone 716-768-8151) - This
family owned company repairs scanners and stocks
parts for several older models. G & G sometimes buys
old scanners, too. They are located at 9247 Glenwood
Drive, LeRoy, NY 14482.
Where Can I Obtain Frequency Information?
To avoid chaos, the FCC licenses two-way radio users and
assigns them specific frequencies. Groups of frequencies
are allocated to specific types of users, so you won't
usually find fire departments using the same frequencies as
taxi drivers, for example.
Scanner enthusiasts can obtain frequency information from
several sources, including books, government microfiche
records, or other listeners.
Books: The most convenient source of fire, police, and
local government frequencies is the Police Call Radio
Guide, published each year in 9 regional volumes by Hollins
Radio Data, and sold at Radio Shack and larger book stores.
I also recommend the book, Monitor America, 2nd edition
published by SMB Publishing, and available from Grove
Enterprises for about $25. This single edition contains
several pages of police, fire, local government, news
media, sports, federal government, and commercial broadcast
frequencies for all 50 states. It contains detailed
communications system profiles and precinct maps for major
metropolitan areas. Police and fire radio codes and unit
identifiers unique to local agencies are listed for several
cities. This differs from Police Call, which gives a more
sterile, but uniform treatment of licensees, listing even
the smallest of towns.
Uniden has published several regional directories using the
"Betty Bearcat" name, although there are much better
directories available from Scanner Master (Newton
Highlands, MA) for some regions.
The most readily available source of sensitive US
government frequencies is still Tom Kneitel's 168 page Top
Secret Registry of US Government Radio Frequencies.
Published by CRB Research, the 6th edition is available
from Grove Enterprises for about $19. Kneitel's book
contains frequency listings for NASA, military, FBI, Secret
Service, DEA, IRS, Border Patrol, arsenals, ammunition
plants, missile sites, and others in the 25 to 470 MHz
range.
Commercial Magazines: Although national in circulation,
local frequency information is sometimes available in
Grove's Monitoring Times (tel. 704-837-9200) and Kneitel's
sensationalistic Popular Communications, (tel. 516-681-
2922). National Scanning Report is a national scanner
magazine published bimonthly and is affiliated with
Uniden's Bearcat Radio Club. It will likely disappoint
experienced scanner hobbyists and is better suited for
beginners. The best scanner frequency lists are often
found in club publications, not commercial magazines, and
are discussed later.
Government Records: Every year, the US Government sells FCC
license information, in the form of microfiche, floppy
disk, and magnetic tape, to the public through the US
Department of Commerce National Technical Information
Service (NTIS). The high cost of buying government records
limits their appeal to hardcore enthusiasts. You can write
for a catalog of FCC Master Frequency Database items to the
NTIS, 5285 Port Royal Road, Springfield, VA 22161.
The FCC has an agreement with PerCon (tel. 716-386-6015), a
private company, to sell FCC license information to the
public on CDROMs. You can buy the full license information
for a multi state region or a less detailed license
database covering the the entire USA on CDROM for about
$100. The DOS access software is somewhat difficult to use
and the frequencies are displayed with annoying leading
zeroes.
Grove enterprises sells FCC license information on floppy
disks. Disks for each state are sold separately, and the
information is basically the same as the FCC "state sort,"
i.e., transmitter location (state/city), callsign, licensee
name, and type of license. Some hobbyists find Grove's DOS
access software is easier to use than the PerCon CDROM
access software.
Over 15% of the FCC licenses, including many fast food
restaurants, contain transmitter latitude and longitude but
specify no transmitter city. To determine the location of
those transmitters requires using the latitude and
longitude information.
I developed a process which produces a color map of FCC
licensed and selected FAA transmitter sites in an area,
given a center location (latitude/longitude) and a range
(in miles). I call this new innovation a RadioMap(TM). It
allows you to identify antenna sites (including paging and
cellular phone cell sites) and visualize the transmitter
locations in your neighborhood, near your office, at an
airport, and other places of interest -- from VLF through
microwave. Streets, rivers, and ham radio stations are not
shown as they would clutter the RadioMap. RadioMap
includes key sheets which list frequencies, callsigns, and
licensee names. In rural areas, ranges of up to 10 miles
are possible, while ranges of 1/2 to 3 miles produce best |
results in urban cities.
Currently, I will produce custom color 8-1/2" by 11" |
RadioMaps, suitable for framing or laminating, only for
areas in Illinois, Indiana, Wisconsin, Michigan, Missouri,
New York, Ohio, and Pennsylvania. Send $19.95 for each |
color RadioMap, your name, address, and telephone number,
along with center location (lat/long or nearest
intersection of 2 streets) to: Bob Parnass, 2350 Douglas
Road, Oswego, IL 60543. tel. 708-554-3839 6-10 PM central
time.
Do Your Own Frequency Detective Work
When you try listening to a frequency for the first time,
you'll want to know who you're hearing.
Although FCC rules require radio users to identify their
operations with their assigned call letters, most ignore
the regulation. This often makes it difficult to know who
is transmitting. Moreover, many radios are now being
placed in service illegally, without first obtaining the
required FCC license.
There is a challenge in deriving new spectrum usage
information on your own. Sometimes it requires several
days of listening, taping, and compiling fragments of
information. Other times, the frequency information is
there for the taking - without hassle.
You can approach from two directions:
1. Listen first: Monitor a frequency or frequencies, and
try to determine who's transmitting and what purpose
the channel serves. Once you identify the user, log
the information.
2. Compile first: Take advantage of opportunities, such
as examining the frequency label on a guard's radio,
or reading the FCC license hanging on the "radio
room" wall, to compile frequency lists, then monitor
the listed frequencies to confirm that they are
really in use. Readers are urged to abide by the
rules of good taste and local laws in the quest for
frequency information. Don't trespass, wait for an
invitation.
Most listeners use a combination of both approaches.
You can examine the FCC license on premise. I have found
the actual FCC radio license, complete with frequency
assignments, hanging on the walls of places like the mall
security office or company guard shack. You can examine
the labels on radio equipment. Frequency information is
engraved on labels on the back of many walkie-talkies, or
inside the battery compartment, like in the Motorola HT220
model. Most pagers have labels on the bottom or inside.
Like passwords taped onto terminals, it's not uncommon to
find labels embossed with frequencies or call letters glued
to the front of base stations.
You can make your own opportunities for eyeing the
equipment or take advantage of "open house" events. If
information is displayed publicly, then a reasonable person
could assume it's not government secret. Hobbyists are
urged to exercise a modicum of restraint and good
judgement, however.
How Can I Use Equipment
to Uncover New Frequencies?
If you don't know the exact frequency, but have a general
idea of the range (e.g. 150 - 152 MHz), use your scanner's
"search" mode. Most programmable scanners afford the
ability to search between two frequency limits set by the
user. A few models, like the ICOM R7000/R7100, and R1, and
older Bearcat 250 and Regency K500, have the ability to
automatically store active frequencies found during an
unattended search operation.
To find the frequency of a hotel communications system, one
fellow installed his Bearcat 250 in his car and parked in
the hotel lot, leaving the scanner in the "search and
store" mode. He left the antenna disconnected so the
scanner would only respond to a transmitter in the
immediate vicinity.
Aside from a scanner and antenna, the most useful piece of
equipment for sleuthing is a voice actuated (VOX) cassette
tape recorder. You don't need a high fidelity model or
anything fancy, a Radio Shack CTR-82 will do. It's best to
use a shielded, attenuating cable to feed the scanner audio
into the recorder rather than relying on the recorder's
internal microphone.
VOX recorders allow one to compress a whole day's worth of
monitoring onto a single tape. I often leave a recorder
"armed" and connected to a scanner at home while I am at
the office or doing something else. When call letters are
mumbled, I can play and replay the tape until I hear and
understand them.
Test equipment can aid in the quest for new frequency
information. I've used a spectrum analyzer connected to an
outside antenna, and a frequency counter for close-in work.
Are There Any Scanner Clubs?
One of the best parts of the hobby is sharing it with other
radio buffs. Trading information with other hobbyists
about frequencies, communication systems, and receiving
equipment is more valuable than any pile of magazines.
The world's largest scanner club is the Radio
Communications Monitoring Association (RCMA). Founded in
1975, the RCMA is the "first national and international
organization of monitor radio listeners." There are
several regional chapters which hold regular meetings.
Club dues are $24.00 per year, which includes the monthly
RCMA Journal, which consists of approximately 95 pages.
Although the focus is on VHF and UHF ranges, there is
coverage of HF utility stations below 30 MHz.
Inquiries about RCMA membership should be sent to RCMA
General Manager, P.O. Box 542, Silverado, CA 92676, USA.
All Ohio Scanner Club
A smaller club is the All Ohio Scanner Club. Its bimonthly
publication, The American Scannergram, is about 60 pages
long. Although concentrating on Ohio, there is frequency
information from other states, and plenty of good product
reviews and scanning tips.
Annual dues are $18 and more information is available from:
Dave Marshall, Managing Editor
All Ohio Scanner Club,
50 Villa Road,
Springfield, OH 45503.
AOSC questions can also be sent electronically to:
rccons!aos...@telerama.pgh.pa.us or
dave.m...@f240.n108.z1.fidonet.org.
FidoNet: 1:108/240.0
AOSC also has a MEMBERS & EDITORS Scanner related echo,
AOSCNet, distributed via FTN on 6 BBS systems, and via
Internet Mailing list. Rick Christian advises these strict
rules for the AOSCNet Scanner Radio Echo (as of 2/1/94):
1. No discussion of cellular modifications or discussions
on how to monitor cellular transmission.
2. No discussions on topics which would violate the ECPA
'84, TDDRA '93, (18 USCA 2510 et seq.) or
Communications Act 1934 & 1984 as amended (47 USCA
705), i.e., decoding/reception of paging, cellular,
encrypted stuff, descrambling etc..
3. No Aliases.
4. No discussion of Shortwave or Amateur Radio material
(except SAREX).
For info on the ECHO only, contact:
R.E. Christian, AOSC PA/AOSCNet Founder
PO BOX 12763,
Pittsburgh PA 15241-0763.
FAX: 412-831-5860.
Internet: rccons!aos...@telerama.pgh.pa.us
rccons!aoscn...@telerama.pgh.pa.us
rick.ch...@f220.n129.z1.fidonet.org
FidoNet: 1:129/220.0
To receive a file of info on the All Ohio Scanner Club via
Internet send to: rccons!ftp...@telerama.pgh.pa.us
In body: get aoscinfo.zip
This will send a UUENCODED info packet to you. The file
contains an outline of the material you will find in the
American Scannergram, the AOSCNet, and an application for
membership. (Note: This file will not be sent back to
*.fidonet.org addresses.)
Chicago Area Radio Monitoring Association
The Chicago Area Radio Monitoring Association (CARMA) is
the foremost club for scanner radio hobbyists in the
northern Illinois area. CARMA was formed from the Chicago
chapter of the Radio Communications Monitoring Association
(RCMA), and we have been meeting since the early 1980s.
Many CARMA members are active in ham radio and GMRS, but
the club is devoted to scanning and scanners.
Meetings are held on Saturdays at area restaurants, about 6
times a year. Although lunch starts at noon, the meetings
begin officially at 1 PM and often run until about 4 PM.
You must purchase a lunch since we get the room for free.
Meetings consist of a quick review of club business,
sometimes a special presentation, and a "round table"
discussion/question & answer session. Large quantities of
information and frequency lists are often distributed in
the form of free handouts. Members sometimes sell radio
equipment at the meetings, too.
In addition to regular meetings, there are two CARMA
picnic/field days during which members meet at a park,
erect antennas, eat, and operate scanners from battery
power. CARMA members take organized tours of various
communications facilities in the area.
Club meeting dates and times are published in the CARMA
newsletter, published 6 times a year. A one year
subscription is available by mailing a $10 check, payable
to Kim Moran, to:
The Command Post
attn. Kim & Ted Moran
6143 W. Touhy Avenue
Chicago, IL 60646
Many CARMA members participate on the CARMA computer
bulletin board, run by Will Sperling. If you have a modem
and terminal or computer, you can reach the CARMA BBS by
calling (708)852-1292.
Here is a tentative meeting schedule for the remainder of
1994. All meetings will be held on Saturdays at the
Destiny Restaurant, 1440 Rand Road, Des Plaines, IL:
October 15
December 10
Bring a notebook and your appetite.
--
==============================================================================
Copyright 1994, Bob Parnass, AJ9S
AT&T Bell Laboratories - par...@ihlpf.att.com - (708)979-5414