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1994-07-05
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HOW DO YOU FIND THESE SCANNER FREQUENCIES?
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.]
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 information in
the fire, police, local government, and conservation
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. This second edition |
is crammed full of police, fire, local government, news
media, sports, national park, and commercial broadcast
frequencies for all 50 states. The information was
compiled mainly from members of the world's largest
scanning club, the Radio Communications Monitoring
Association (RCMA). Monitor America 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.
Scanner Master also publishes regional frequency guides for
Illinois, Florida, Virginia, Massachusetts, New Jersey, and |
other states.
Beyond Police Call, available from several sources |
including Radio Shack, covers the business, schools, and |
other stations not covered by Police Call, its sister |
publication. One volume covers the entire USA, but no call |
signs are shown. |
Aeronautical frequencies are covered in the Aeronautical
Frequency Directory, written by Bob Coburn, W1JJO.
Although most of the information is about civilian
aviation, Bob included sections on military mid-air
refueling and CAP. The second edition is about 400 pages
and is available from Official Scanner Guide. The same |
publisher sells the Maritime Frequency Directory and
frequency guides for several New England states. Some of
these books are available through Radio Shack, too.
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 $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 frequencies, most of the information in Kneitel's
book has been collected from listeners over the years. It
is certainly 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. |
Magazines
Although national in circulation, local frequency
information is sometimes available in Grove's Monitoring
Times and Kneitel's sensationalistic Popular
Communications.
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).
These lists contain license information for the industrial
(e.g. Illinois Armored Car, Pinkerton's Security, Joe's
Towing, etc.), highway maintenance, commercial broadcast,
aviation, common carrier, and maritime services, 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.
The FCC has an agreement with PerCon (tel. 716-386-6015), a |
private company, to sell FCC license information to the |
public on both floppy disks and 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. |
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' information about
federal government radio stations under the Freedom of
Information Act (FOIA)1. Only 12 of the 21 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 'classified'2.
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 information
is marked 'unclassified', but all fields are furnished,
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 hobbyists
about frequencies, communication systems, and receiving
equipment is more valuable than a pile of magazines.
Since the early 1960s, I had been an amateur radio |
operator, and belonged to amateur radio clubs, but 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,
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
publication, 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
information. 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.
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" 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. |
What Makes Station Identification Difficult?
In most instances, FCC rules require radio users to
identify their operations with FCC assigned call letters.
Police and fire departments, especially those with trained
radio dispatchers, seem particularly conscientious 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
nondescriptive "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 identity.
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. |
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 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 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
equipment or take advantage of "open house" events. If
information 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
frequencies.
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 county building,
noticed a new unattended repeater installation 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 Service, and opening the access
door could have activated a "tamper alarm"!
The tech was skating on thin ice. He had nobody's
permission 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 disconnected 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! (one may use FCC license |
microfiche, described in Part I of this article, to |
identify stations using call letters.) Transmissions were
short and infrequent, so it was decided to tape record all
transmissions on this frequency for several days to
determine the station's identity.
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 supplied power
to the recorder only during radio transmissions, 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. During 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 Center (XYZ is a pseudonym for the |
actual licensee name.)
Lisle, Illinois *
I watched the driver pick up a microphone, and listened to
him on my portable scanner checking back with his "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 manufacturer.
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. |
Addresses |
|
Grove Enterprises, |
PO Box 98, |
140 Dog Branch Road, |
Brasstown, NC 28902. |
tel (704)837-9200 |
Official Scanner Guide, |
PO Box 712, |
Londonderry, NH 03053. |
Scan America, |
430 Garner Drive, |
Suffield, OH 44260-1557 |
|
Scanner Master, |
PO Box 428, |
Newton Highlands, MA 02161. |
telephone 1-800-722-6701. |
__________
1. See "The Government Giveth, the Government Taketh Away",
by Richard Prelinger, in Monitoring Times, July 1982.
2. See "AFIO and the FOIA", by Bob Grove, in Monitoring
Times, September 1982.
--
==============================================================================
Copyright 1994, Bob Parnass, AJ9S
AT&T Bell Laboratories - parnass@ihlpf.att.com - (708)979-5414