[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
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