Introduction to Scanning
Bob Parnass, AJ9S
Last changed: October 15, 1996.
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Introduction to Scanning
by Bob Parnass, AJ9S
[NOTES: 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. It is posted twice monthly on the USENET
groups rec.radio.scanner, alt.radio.scanner, and
rec.radio.info. It is also available electronically from
the rec.radio.scanner ftp archive on the official USENET
FAQ library ftp://rtfm.mit.edu/pub/usenet-by-
group/rec.radio.scanner.]
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.
The author writes a monthly "Scanner Equipment" column for
Monitoring Times magazine, published by Grove Enterprises,
but views expressed in this article are his own.
Why Scanning?
Every day and night, scanner hobbyists are entertained by
what they overhear on their radios. Police cars, fire
engines, ambulances, airplanes, armored cars, trains,
taxis, 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, neighbor and
domestic disputes, 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?
Baby monitor intercoms are actually transmitters and you
can hear them between 49.67 and 49.99 MHz.
Stay ahead of road conditions by listening to highway road
crews, snow plows, and traffic helicopter pilots. Many
midwesterners monitor the state police and and county
sheriff to learn of approaching tornados long before
warnings are broadcast on TV and commercial radio. 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.
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. Public law 103-414, signed
Oct. 25, 1994, amended the law (Title 18 USC, Part I,
chapter 119, sections 25110 and 2511) and outlaws listening
to cordless phones, too, 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 laws.
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 paperback book, Listeners
Lawbook, compiled by Frank Terranella, Esq. available for
$9.95 + shipping from Grove Enterprises, PO Box 98,
Brasstown, NC 28902.
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 are actually manufactured by both GRE (General
Research Electronics) and by Uniden. Personally, I don't
recommend Trident nor many of the AOR brand scanners,
although the AR8000 and AR3000 have good reputations.
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
have larger displays and almost always provide more audio
than portables, and some portables are 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 40 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 second rate.
Deluxe scanners can be controlled and/or downloaded by a
personal computer, a feature which appeals to a small but
growing number of scanner owners.
Almost all low and mid-priced scanners are prone to
receiving images -- receiving the same signal erroneously
on two or more frequencies. With a few exceptions, images
are unwelcome due to the interference they cause, e.g.,
hearing aircraft transmissions while the scanner is tuned
to the local police frequency. Premium quality scanners
use "up conversion" circuitry, a scheme which greatly
reduces, but does not eliminate, image reception.
Currently, the more popular scanners include the
Uniden/Bearcat BC760XLT (a/k/a 950XLT) and discontinued
Radio Shack PRO-2006 base/mobiles, the Uniden/Bearcat
BC200XLT (a/k/a BC205XLT), BC220XLT, and Radio Shack PRO-43
portables. A number of owners report problems with the
Icom R1 portable and the older Uniden/Bearcat 8500XLT base
and 2500XLT portable. The new Uniden BC9000XLT base and
BC3000XLT portable work very well and are my current
favorites.
Considered by many as the best scanner ever made, the 400
channel Radio Shack PRO-2006 was replaced by the 1000
channel PRO-2035, which was replaced by the PRO-2042. The
portable Radio Shack PRO-62 and PRO-60 are good performers.
All five models employ up conversion and are made for Radio
Shack by GRE (General Research Electronics).
Scanner Antennas
All scanners come with a built in antenna, permitting
reception up to about 20 miles or so.
Portable scanners are supplied with a helical (spring
shaped) antenna, covered by rubber. The rubberized
antennas furnished with current models are too stiff and
place stress on the antenna jack. Older scanners to be
supplied with more flexible antennas. I prefer to replace
the stock antenna with an Icom FA-1433B dual band flex
antenna which is thin and very flexible while providing
better performance than a stock antenna.
Although it is small and somewhat tolerant of physical
abuse, the range of a heliflex antenna is very limited.
Augmenting it with a 19" telescoping metal antenna can
improve portable reception greatly.
Since 1988, I've used the "Thin-Stick" 18 inch telescoping
antenna for extended range on my portable scanners and 2
meter walkie-talkies. The Thin-Stick, made in USA by
Smiley Antenna Co., Inc., is designed to cover both the 2
meter and 220 MHz bands, but its variable length means it
can be adjusted for optimum performance on other bands.
What makes the Thin-Stick different from an ordinary
telescoping antenna is the spring between the antenna and
the connector portions. The spring absorbs most of the
impact if the antenna collides with an object. The street
price is about $17 and it is available from Amateur
Electronic Supply, Milwaukee and other retailers.
Outdoor antennas, like the Channel Master 5094A or Antenna
Specialists AV-801 (recently discontinued), 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 more prone to
cause scanner damage due to static charge buildup because
they are not at "DC ground."
Coaxial Cable Feedlines
If your antenna installation requires more than 50 feet of
feedline, use RG213/U or high quality RG8/U coaxial cable.
RG213/U has a non-contaminating jacket and will last
longer. Each has an outer diameter of about 13/32".
Similarly sized Belden 9913 cable and clones have lower
attenuation but are difficult to bend, require special
connectors, and can accumulate moisture inside because they
are hollow.
If you must use a small diameter cable for long runs, use
RG6/U. Avoid RG58/U (7/32" OD) due to its losses at high
frequencies. RG8/X (1/4" OD) is suitable for short patch
cords.
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.
Telephone (orders only): (800)438-8155. Web page is
http://www.grove.net
- National Electronics (formerly National Tower
Company), PO Box 15417, Shawnee Mission, KS 66215.
Telephone (800)762-5049, (913)888-8864. Web page is
http://www.sound.net/~ne/
- The Ham Station, 220 N. Fulton Ave., Evansville, IN
47719-0522. Telephone (800)729-4373, (812)422-0231.
- Scanner World (Albany, NY). Telephone (518)436-9606.
- Amateur Electronics Supply (Milwaukee, WI). Telephone
(800)558-0411.
Beware of inflated "shipping and handling" charges and be
sure to include these when comparison shopping.
Used scanners may be found at hamfests, flea markets,
garage sales, or listed in the classified advertisement
section of your newspaper.
Modifying Your Scanner
The term "mod" is often used as shorthand for
"modification." If you are handy with a soldering iron,
you may be interested in modifying ("modding") your scanner
to add features or enhance its performance. Be warned this
usually voids your warranty and current models are
difficult to service due to the small, delicate surface
mount components. By federal regulation, new scanner
models cannot be easily modified to tune the cellular phone
bands.
The term "mod" has been narrowly used by some people to
mean a change which permits a scanner to receive cellular
phone frequencies. This definition is far too restrictive
as there are several ways one could modify a scanner, e.g.,
changes to improve audio quality, adding an S-meter,
expanding the number of channels, changing the earphone
jack to accept stereo headphones, etc.
Modification article files can be copied from several ftp
sites including the /pub/ham-radio/mods directory at:
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
If you cannot find files describing modifications to a
particular scanner, it's probably because nobody bothered
to devise a modification, or more likely, nobody has taken
the time to document their modification.
Modification articles posted on Usenet seem to have a life
of their own. Frequently, they are plagiarized from the
Internet and compiled by book, CDROM, and magazine
publishers, sometimes reworded, then sold. Hobbyists then
copy the modifications from the books, CDROMs, and
magazines back onto the Internet or BBSs (bulletin board
systems)!
Grove Enterprises and other companies advertise a
warranted, modification for fee service.
Scanner Repair Shops
Is your scanner broken? Aside from sending the scanner
back to the manufacturer for repair, here is one company
which repairs scanners:
- G & G Communications (telephone 716-768-8151) -
(http://www.iinc.com/ggcomm/ or email ggc...@iinc.com
or ggc...@aol.com) This family owned company repairs
scanners and pagers and stocks parts for several older
models. G & G cannot usually repair AOR scanners due
to lack of manufacturer support. G & G sells and
sometimes buys old scanners and parts, 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 Gene Hughes' Police Call,
published each year in 9 regional volumes by Hollins Radio
Data, and sold at Radio Shack and larger book stores. The
1996 editions contain selected business listings, too,
although callsigns are listed only for local government and
public safety licensees.
I also recommend the book, Monitor America, published by
SMB Publishing (now known as Scanner Master Publishing),
and available from Grove Enterprises for about $30. A new,
1100 page 3rd edition is now available. Monitor America
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, tel. (508)655-6300) for some regions.
The most readily available source of sensitive US
government frequencies is still Tom Kneitel's Top Secret
Registry of US Government Radio Frequencies. Published by
CRB Research, the 8th edition is available from Grove
Enterprises for about $22. 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.
Tab Books Master Frequency File, first edition, written by
James Tunnell and Robert Kelty, lists federal agencies and
frequencies and deserves a read. However, there are no
military listings and many pages are devoted to appendices
and references which contain no frequency listings. The
space would be much better used by a combined federal
frequency list sorted by frequency.
Commercial Magazines: Although national in circulation,
local frequency information is sometimes available in
Grove's Monitoring Times (tel. 704-837-9200) and the
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. Early issues disappointed
experienced scanner hobbyists, but it now has a good column
on scanner modifications and has greatly improved its
coverage of east coast frequencies since merging with NESN
(North East Scanner News). The best scanner frequency
lists are often found in club publications, not commercial
magazines, and are discussed later.
The Scanner Club is the name of a bimonthly magazine
published by Les Mattson. It is a successor to the
Northeast Scanning News and is the official publication of
The Scanner Club, a not-for-profit club organization.
TSC's main strength is local frequency information,
including CTCSS codes. Sample issues are $4 each. A
yearly membership costs $24.95 and includes 6 issues.
Write to The Scanner Club, PO Box 62, Gibbstown, NJ 08027
for more information.
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 PerCon Spectrum CDROM sells for $29 and contains
a handful of fields for every FCC license in the US. The
Spring 1995 edition works in DOS, Windows, and Mac
environments.
Grove enterprises sells FCC license information on CDROM
for $100. In the 1995 edition, fields are different than
PerCon's Spectrum CDROM but the data appears to be of the
same vintage. The licensee name and licensee city are used
instead of the DBA (doing business as) name and transmitter
city which makes query results confusing.
As I have already done for hundreds of radio enthusiasts,
companies, government agencies, and organizations across
the country, I will locate FCC licensed and selected FAA
and CAP transmitter sites in an area of your choice, in any
state, and produce a custom RadioMap(TM) report, including
an 8-1/2" by 11" scaled color map, protected by plastic.
The map is marked with transmitter sites, cities, highways,
airports, military installations, national parks, etc.
The graphical nature of RadioMap allows you to identify
antenna sites and visualize the transmitter locations in
your neighborhood, near your office, and other places of
interest -- from VLF through microwave. The report lists
frequencies, callsigns, and licensee names. RadioMap
covers police, fire, local government, TV, business,
industry, common carrier, railroad, trucking, and many more
types of transmitter sites, excluding ham radio stations.
Wireline and nonwireline cellular phone and AM/FM broadcast
transmitter sites are clearly marked using unique color
icons.
Industrial customers use RadioMap reports to survey the
"radio environment" prior to installation of radios and
wireless microphones at customer sites. RadioMap is used
by the maritime and broadcast industries, as well as ham
radio operators to solve intermod interference problems,
and has been very favorably reviewed in RCMA Scanner
Journal, American Scannergram, and USSN.
The RadioMap processes and software are unique and
proprietary. Unlike "more tame" maps, RadioMap shows the
locations of military bases, ammunition plants, arsenals,
weapons factories, and other military installations.
For a flat fee, you choose the center location, and I
choose the range, depending on transmitter site density:
suburbs: 5 mile range (100 sq. mi. area)
rural areas: 10 or more miles (400 sq. mi. area)
dense urban area: 1 - 2 mile range
Longer ranges for additional charge - call for pricing.
A custom RadioMap report costs $20.95 plus $5.00 shipping
and handling. For an additional $4.00, I will include a
custom frequency allocation histogram, a 0 - 1,000 MHz
"spectrum analyzer-like" display showing spectrum usage by
the transmitters in the map coverage area. Send check or
money order payable to Bob Parnass for $25.95 for standard
or $29.95 for deluxe RadioMap report with histogram.
Include your name, address, and telephone number, along
with center location (nearest intersection of 2 streets, or
latitude & longitude) and mail to: Bob Parnass, 2350
Douglas Road, Oswego, IL 60543. tel. (630)554-3839 6-10 PM
central time. For a brochure, send SASE.
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 systems to identify their
operations with their assigned call letters either
automatically or verbally, 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 or Mailing List?
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.
Peter Laws administers an electronic mail list read by over
700 hobbyists devoted to scanners and scanning. It's called
"scan-l" and for more information, read:
http://www.excalibur.net/~plaws/scan/scan-l.txt
Clay Irving <cl...@panix.com> administers a scanner
electronic mailing list, called "scanning." To subscribe,
send an Email message to: majo...@lists.panix.com
In the body of the Email message, put: subscribe scanning
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 and the Northeastern
states, there is frequency information from other states,
and plenty of good product reviews and scanning tips.
Annual dues are $18.50 and more information is available
from:
Dave Marshall, Managing Editor
All Ohio Scanner Club,
50 Villa Road,
Springfield, OH 45503.
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, many 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 often 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 $15 check, payable
to Kim Moran, to:
CARMA
P.O. Box 2681
Glenview, IL 60025
Some CARMA members participate on the CARMA computer
bulletin board, run by Will Sperling. There is a $15
annual fee for the BBS. If you have a modem and terminal
or computer, you can reach the CARMA BBS by calling
(630)852-1292.
All meetings are held on Saturdays at locations announced
in advance. Meetings are usually held at:
- the Destiny Restaurant, on Rand Road, in Des Plaines,
- Philly's in the shopping center at the corner Rt. 83
and 53rd St. in Willowbrook,
- The Great Escape, on Irving Park Road, Schiller Park
and at other restaurants.
--
==============================================================================
Copyright 1996, Bob Parnass, AJ9S par...@bell-labs.com
Locate & identify transmitters in your area with RadioMap(tm)