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From X Tue Feb 1 14:30:29 EST 1994
Article: 3561 of rec.radio.scanner
Xref: northshore rec.radio.scanner:3561 alt.radio.scanner:9227 rec.radio.info:3107
Lines: 440
Subject: Introduction to Scanning, posted monthly
Organization: AT&T Bell Laboratories, Naperville, IL
Followup-To: poster
Keywords: FAQ food, motivation, scanner sources, books, clubs
Approved: rec-radio-info@ve6mgs.ampr.ab.ca
Path: northshore!noc.near.net!yale.edu!yale!gumby!destroyer!nntp.cs.ubc.ca!alberta!ve6mgs!usenet
Date: Mon, 31 Jan 1994 18:18:34 MST
From: parnass@ih4gp.att.com
Newsgroups: rec.radio.scanner,alt.radio.scanner,rec.radio.info
Message-ID: <CKIuAp.4v3@cbnewse.cb.att.com>
Last changed: January 17, 1994
Introduction to Scanning
by Bob Parnass, AJ9S
[NOTE: This article may not be reproduced in whole or in
part 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 scan-
ning hobby and is oriented to scanning in the USA. It
tells where you can buy your first scanner, what features
it should have, how to get frequency information, and men-
tions 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, air-
planes, 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 to your neighbors deal drugs over their cordless
telephone, or as their conversations are picked up and
transmitted over the airwaves by their sensitive baby moni-
tor intercom. Yes, it's legal to listen, and it's all
there in the 46 and 49 MHz ranges.
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 micro-
phone 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 Commun-
ications 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 frequen-
cies, and it's clear that Americans still listen to what-
ever they want in the privacy of their own homes despite
the ECPA. Change is in the wind -- it will soon be illegal
for companies to sell scanners which 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 scan-
ning while in your car. Indiana restricts some portable
scanners. 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 manufac-
tured by both GRE (General Research Electronics) and by
Uniden. Personally, I don't recommend AOR brand scanners.
Scanners are available in two varieties: crystal controlled
and programmable. The crystal controlled models are
cheaper, but require the user purchase and install a $5
crystal for each frequency of interest. Programmable (syn-
thesized) units are replacing crystal controlled models as
they don't require crystals and usually have a keypad that
permits you to store frequencies into channels. Programm-
ables are now so cheap it doesn't make sense to buy a crys-
tal 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.
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 unless you live in a very
rural area where this band is not used. Usage of the
800 MHz band is growing by leaps and bounds.
If you're not sure whether you'll like scanning, don't want
to spend much money, a 16 channel radio will do. In gen-
eral, 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 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 most scanner own-
ers.
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.
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 Service Merchandise and Circuit City sell scanners,
but carry just a few models. Department stores, like Sears
and Montgomery Wards, sometimes offer 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.
- Scanner World (Albany, NY). Telephone (518)436-9606.
- National Tower Company, PO Box 15417, Shawnee Mission,
KS 66215. Telephone (913)888-8864.
- Marymack Distributing (Katy, TX) sells Radio Shack
scanners at discount. Telephone (713)392-0747.
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, or
listed in the classified advertisement section of your
newspaper.
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 usu-
ally 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 com-
munications 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 direc-
tories available from Scanner Master (Newton Highlands, MA)
for some regions.
The most readily available source of sensitive US govern-
ment 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 fre-
quency listings for NASA, military, FBI, Secret Service,
DEA, IRS, Border Patrol, arsenals, ammunition plants, mis-
sile 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. 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 Ser-
vice (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.
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.
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 infor-
mation 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 equip-
ment or take advantage of "open house" events. If informa-
tion 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, how-
ever.
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 abil-
ity 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 automati-
cally 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 immedi-
ate 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 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 Communica-
tions 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 sta-
tions below 30 MHz.
Inquiries about RCMA membership should be sent to RCMA Gen-
eral 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!aosc_hq@telerama.pgh.pa.us or
dave.marshall@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. 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!aosc_pa@telerama.pgh.pa.us
rccons!aoscnet_hq@telerama.pgh.pa.us
rick.christian@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!ftpmail@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.)
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 direc-
tory at:
ftp.cs.buffalo.edu
garfield.catt.ncsu.edu
world.std.com
--
==============================================================================
Copyright 1994, Bob Parnass, AJ9S
AT&T Bell Laboratories - parnass@ih4gp.att.com - (708)979-5414
From X Tue Feb 1 14:30:43 EST 1994
Article: 3562 of rec.radio.scanner
Xref: northshore rec.radio.scanner:3562 alt.radio.scanner:9228 rec.radio.info:3108
Lines: 694
Subject: How to Find Scanner Frequencies, posted monthly
Organization: AT&T Bell Laboratories, Naperville, IL
Followup-To: poster
Keywords: FAQ food, freq guides, microfiche, sleuthing
Approved: rec-radio-info@ve6mgs.ampr.ab.ca
Path: northshore!noc.near.net!yale.edu!yale!gumby!destroyer!nntp.cs.ubc.ca!alberta!ve6mgs!usenet
Date: Mon, 31 Jan 1994 18:22:01 MST
From: parnass@ih4gp.att.com
Newsgroups: rec.radio.scanner,alt.radio.scanner,rec.radio.info
Message-ID: <CKIuG7.51x@cbnewse.cb.att.com>
x-------------- CUT
- 1 -
[last updated August 10, 1993]
HOW DO YOU FIND THESE SCANNER FREQUENCIES?
Part 1: Books, Magazines, Government Records, and Clubs
by Bob Parnass, AJ9S
[NOTE: This article may not be reproduced in whole or in
part in bulletin boards, networks, or publications which
charge for service without permission of the author.
Free distribution is encouraged.]
I am often asked, "How do you find these frequencies?"
Scanner enthusiasts can obtain frequency information from
several sources, including books, government microfiche
records, or other listeners.
Books
The most convenient source of fire and police 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 for under $10. Police Call
is basically a computer printout of FCC license informa-
tion in the fire, police, local government, and conserva-
tion services in two lists: by licensee name within
state, and by frequency. Later editions have included a
few pages of local airport and nonsensitive federal
government frequencies.
I highly recommend Richard Prelinger's 1992 book, Monitor
America, published by Scanner Master Corp., and available
from Grove Enterprises for about $25.1 This second edi-
tion is crammed full of police, fire, local government,
news media, sports, national park, and commercial broad-
cast frequencies for all 50 states. The information was
compiled mainly from members of the world's largest scan-
ning club, the Radio Communications Monitoring Associa-
tion (RCMA). Monitor America contains detailed communi-
cations system profiles and precinct maps for major
metropolitan areas. Police and fire radio codes and unit
identifiers unique to local agencies are listed for
__________
1. Grove Enterprises, PO Box 98, 140 Dog Branch Road,
Brasstown, NC 28902. tel (704)837-9200
- 2 -
several cities. This differs from Police Call, which
gives a more sterile, but uniform treatment of licensees,
listing even the smallest of towns.
Scanner Master also publishes regional frequency guides
for Illinois, Florida, Virginia, Massachusetts, New Jer-
sey, and other states.2
Aeronautical frequencies are covered in the Aeronautical
Frequency Directory, written by Bob Coburn, W1JJO.
Although most of the information is about civilian avia-
tion, Bob included sections on military mid-air refueling
and CAP. The second edition is about 400 pages and is
available from Official Scanner Guide.3 The same pub-
lisher sells the Maritime Frequency Directory and fre-
quency guides for several New England states. Some of
these books are available through Radio Shack, too.
The most readily available source of sensitive US govern-
ment frequencies is still Tom Kneitel's Top Secret Regis-
try of US Government Radio Frequencies. Published by CRB
Research, the 8th edition is available from Grove Enter-
prises for about $20. 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. Since the
US government no longer offers frequency information for
its own stations, and has never published sensitive fre-
quencies, most of the information in Kneitel's book has
been collected from listeners over the years. It is cer-
tainly not complete, nor 100% accurate, but is the best
book in print for this difficult to obtain information.
A more accurate, but smaller and less comprehensive book
is Midwest Federal Frequency Directory. It was published
in 1986, and copies are getting scarce. Copies may still
be available for $10 from Scan America.4
__________
2. Scanner Master, PO Box 428, Newton Highlands, MA 02161.
telephone 1-800-722-6701.
3. Official Scanner Guide, PO Box 712, Londonderry, NH
03053.
4. Scan America, 430 Garner Drive, Suffield, OH 44260-1557
- 3 -
Magazines
Although national in circulation, local frequency infor-
mation is sometimes available in Grove's Monitoring Times
and Kneitel's sensationalistic Popular Communications.
Government Records
Every year, the US Government sells FCC license informa-
tion, in the form of microfiche, floppy disk, and mag-
netic tape, to the public through the US Department of
Commerce National Technical Information Service (NTIS).
These lists contain license information for the indus-
trial (e.g. Illinois Armored Car, Pinkerton's Security,
Joe's Towing, etc.), highway maintenance, commercial
broadcast, aviation, common carrier, and maritime ser-
vices, as well as for police and fire. For more info
call NTIS at 703-487-4630.
Microfiche is not for the casual hobbyist, but rather for
the ardent listener, who can easily spend a few hundred
dollars for the fiche, not including the price of a
microfiche reader.
Back in "the good old days," Grove Enterprises sold
copies of some FCC microfiche files, and this was much
cheaper than buying directly from NTIS. Grove no longer
sells microfiche, but sells the information on PC floppy
disks for each state instead.
Companies have appeared which are "plugged into" the FCC
licensing system and they sell computer time allowing
on-line file access. They also sell paper copies of FCC
information. Washington Radio Reports is one example. A
monthly publication, it lists license applications made
to the FCC. A few members of my scanner club subscribe
and share the information with me.
Federal Radio Stations - Not Licensed by FCC
Since federal government radio stations are not licensed
by the FCC, they are not listed in FCC microfiche. In
1981, a group of 60 radio hobbyists split a $1300 fee,
and obtained 80 microfiche cards of 'sanitized' informa-
tion about federal government radio stations under the
Freedom of Information Act (FOIA)5. Only 12 of the 21
- 4 -
information fields for each station were furnished.
Fields like "Remarks", which indicate the exact usage of
a channel (e.g. "Sky Marshall's Net"), and "Bureau",
indicating agency subdivision (e.g. TAC within the
USAF), were withheld. These 80 pages of microfiche were
sold by Grove Enterprises for $25, but are no longer
available from that source. Private entrepreneurs have
been known to ask $125 or more for a set! In a step
backward, the US Government insists it will no longer
release this type of information - it is now 'classi-
fied'6.
For a reason unknown to this author, the government
released a 1984 vintage set of frequencies allocated to
the FAA. Perhaps this was a mistake, because the infor-
mation is marked 'unclassified', but all fields are fur-
nished, including some which indicate security related
usage. Grove sold this set of 33 microfiche cards for
about $13.
Radio Clubs
One of the best parts of the hobby is sharing it with
other radio buffs. Trading information with other hobby-
ists about frequencies, communication systems, and
receiving equipment is more valuable than a pile of maga-
zines.
In 20 years of being an amateur radio operator, and
belonging to amateur radio clubs, I never realized there
were any scanner clubs! In 1983, I joined the world's
largest scanner club, 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 collected annually, which covers
a monthly newsletter, the RCMA Scanner Journal, about 95
pages long. Although the focus is on VHF and UHF ranges,
__________
5. See "The Government Giveth, the Government Taketh Away",
by Richard Prelinger, in Monitoring Times, July 1982.
6. See "AFIO and the FOIA", by Bob Grove, in Monitoring
Times, September 1982.
- 5 -
there is coverage of HF utility stations below 30 MHz. A
recent liberalization of club policy now permits the
printing of most federal law enforcement frequencies,
e.g., Secret Service, FBI, Customs, and DEA.
Inquiries about RCMA membership should be sent to:
RCMA General Manager
P.O. Box 542
Silverado, CA 92676
USA
Another club which prints sensitive federal frequencies
is the All Ohio Scanner Club. I enjoy its bimonthly pub-
lication, The American Scannergram, which is about 60
pages long. Although concentrating on Ohio, there is
frequency information from other states, and plenty of
product reviews and scanning tips.
More information is available from:
All Ohio Scanner Club
50 Villa Road
Springfield, OH 45503
Do Your Own Sleuthing
The real challenge is deriving new spectrum usage infor-
mation. 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.
More about sleuthing will be discussed in Part II of this
article.
- 6 -
HOW DO YOU FIND THESE SCANNER FREQUENCIES?
Part 2: Sleuthing
by Bob Parnass, AJ9S
[NOTE: This article may not be reproduced in whole or in
part in bulletin boards, networks, or publications which
charge for service without permission of the author.
Free distribution is encouraged.]
Part I of this series discussed how scanner enthusiasts
can obtain frequency information from books, government
microfiche records, or other listeners. This installment
discusses digging up new frequencies on your own.
Do Your Own Sleuthing
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 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" wall7, to compile frequency lists,
then monitor the listed frequencies to confirm that
they are really in use.
Most listeners use a combination of both approaches.
What Makes Station Identification Difficult?
__________
7. 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.
- 7 -
In most instances, FCC rules require radio users to iden-
tify their operations with FCC assigned call letters.
Police and fire departments, especially those with
trained radio dispatchers, seem particularly conscien-
tious about station identification. Like commercial
broadcasters, many of these stations identify on the hour
and the half hour.
Some repeater stations have Morse code identification
circuits which transmit call letters on a periodic basis,
insuring compliance with FCC rules.
On the other hand, over 75% the industrial radio stations
monitored within the last year ignore the FCC regulation,
making it difficult for a listener to identify a station.
Some stations may operate for years using the nondescrip-
tive "base to mobile 2" or "Joe to base" protocol. One
rung up the hierarchy are stations that identify using
something like "Acme base to 107", giving the listener a
clue for his log. If call letters are given, they are
often rendered unintelligible by operators who fail to
enunciate. The failure to identify is more likely due to
sloppiness, rather than any attempt to hide station iden-
tity.
While not regulated by the FCC, federal government radio
stations vary in the extent to which they identify their
transmissions. Some federal stations do not have call
letters. A nearby paging transmitter periodically
transmits a voice recording announcing, "This is the Army
Joliet Ammunition Plant." What more could a listener ask
for?
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. I use two modified Radio Shack
CTR-75 recorders, a discontinued model.
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.
The following examples illustrate techniques I've used to
derive new frequency information.
- 8 -
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 Bell Labs security office and the guard shack at
Waste Management's Greene Valley Landfill in Naperville.
Examine the Labels on Radio Equipment
Frequency information is engraved on labels on the back
of many walkie-talkies, or inside the battery compart-
ment, 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 Dymo tape
labels embossed with frequencies or call letters glued to
the front of base stations.
You can make your own opportunities for eyeing the equip-
ment or take advantage of "open house" events. If infor-
mation is displayed publicly, then a reasonable person
could assume it's not government secret.
- At the annual Glenview Naval Air Station open house,
I examined a military manpack radio being used by
dispensary paramedics. The radio's tuning dial was
set at 34.15 MHz.
- The Illinois Army National Guard displayed two
armored personnel carriers at the local county fair,
each equipped with VHF-FM and HF-SSB transceivers.
In addition to a tuning control (VFO), the VHF-FM
radio had a set of channel select pushbuttons, much
like those in a car radio. I asked a guardsman a few
questions about the radio, and he demonstrated the
channel preset feature. A panel above the channel
pushbuttons was labeled with the frequencies:
32.055, 34.45, 35.35, 40.55, and 40.60 MHz.
- An Army National Guard UH1 helicopter was displayed
at the Marseilles armory "open house". The public
was permitted to climb aboard, and observe the
instrumentation and radio gear. A channel plate on
the instrument cluster listed over a dozen frequen-
cies.
Hobbyists are urged to exercise a modicum of restraint
and good judgement. In New Jersey, a radio
technician/hobbyist called to service a transmitter in a
- 9 -
county building, noticed a new unattended repeater ins-
tallation in the same room. Being curious about what
frequency this repeater was on, he opened the access door
to copy the frequencies from the radio's crystals. It
turns out that this radio belonged to the US Secret Ser-
vice, and opening the access door could have activated a
"tamper alarm"!
The tech was skating on thin ice. He had nobody's per-
mission to tamper with that equipment.
Equipment to Determine Frequency Usage
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. Some models, including the ICOM
R7000/R7100, Bearcat 2500XLT, and Bearcat 250, 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 discon-
nected so the scanner would only respond to a transmitter
in the immediate vicinity.
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.
How Can I Determine To Whom I'm
Listening? - An Example
While scanning the industrial frequencies in the 150 MHz
range, a van driver was overheard communicating with
"base" while driving around my town. The stations
involved never used FCC call signs -- this would have
made life a lot easier for me, and legal for them!8
__________
8. One may use FCC license microfiche, described in Part I
of this article, to identify stations using call
- 10 -
Transmissions were short and infrequent, so it was
decided to tape record all transmissions on this fre-
quency for several days to determine the station's iden-
tity.
During daylight hours, a modified Regency K500 scanner
was left tuned to the target frequency, connected to a
cheap tape recorder through a home built interface.
Using a carrier operated relay, the tape interface sup-
plied power to the recorder only during radio transmis-
sions, so a day's worth of traffic could be compressed
into a 45 minute tape.
Each day, the tape was played back and notes on names,
locations, and activities mentioned during the day's
transmissions were taken. The van driver appeared to be
making daily stops at a local bank and two shopping
malls. A Walgreen's store seemed to be the only stop at
one mall. A few times, "base" ordered the van "back to
the Training Center." There were frequent references to
"guests checking out", "dropping a guest off", and
"instructor[s] missing a class". At times, "base" spoke
with "security", who must have been using a walkie-talkie
as his signals weren't strong enough to hear.
Was this a hotel? Calls to the three local hotels
revealed that none provides shuttle bus service to the
shopping malls. A call to the Walgreen's, inquiring
about bus service to the store, drew another blank. Dur-
ing my shopping trips, I began to pay closer attention to
vans with antennas driving through the parking lots.
I was leaving the mall one day, when a week's effort paid
off. A maroon and white van, equipped with a VHF-Hi
antenna, was dropping shoppers off at Walgreen's. A sign
on the van's door read:
XYZ Central Training Center9
Lisle, Illinois
I watched the driver pick up a microphone, and listened
to him on my portable scanner checking back with his
____________________________________________________________
letters.
9. XYZ is a pseudonym for the actual licensee name.
- 11 -
"base".
All the pieces fit: the "guests", the "classes", the
"instructors". Mystery solved; I had been monitoring the
customer training center for a large computer manufac-
turer. The training center has hotel rooms and dining
facilities to accommodate students from out of state. As
a convenience, shuttle van service is provided to local
shopping malls.
Summary
Through books, government records, and radio clubs,
scanner listeners can make use of frequency information
compiled by others. Two-way radio users often fail to
identify their transmissions properly, making it more
difficult for listeners to know who they are monitoring.
By examining radio equipment labeling, and monitoring and
taping transmissions, scanner enthusiasts can unearth new
information.
--
==============================================================================
Copyright 1994, Bob Parnass, AJ9S
AT&T Bell Laboratories - parnass@ih4gp.att.com - (708)979-5414