Search the FAQ Archives

3 - A - B - C - D - E - F - G - H - I - J - K - L - M
N - O - P - Q - R - S - T - U - V - W - X - Y - Z - Internet FAQ Archives

How to Find Scanner Frequencies

[ Usenet FAQs | Web FAQs | Documents | RFC Index | Schools ]
last changed March 21, 2001

See reader questions & answers on this topic! - Help others by sharing your knowledge
 Lines changed since the previous issue are marked with a |
 character in the right margin.


                    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.  It is posted twice monthly on the USENET
 groups,, and  It is also available electronically from
 the ftp archive on the official USENET
 FAQ library
 group/  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.]

 I am often asked, "How do you find these frequencies?"
 This article answers the question in various sections:

  Government Records
  Web Sites
  Federal Radio Stations
  Radio Clubs
  Do Your Own Sleuthing
  What Makes Station Identification Difficult?
  Examine the FCC License on Premise
  Examine the Labels on Radio Equipment
  Examine the Antenna to Determine Frequency Band
  Equipment to Determine Frequency Usage
  How Can I Determine To Whom I'm Listening? - An Example


 The most convenient source of fire and police frequencies
 is the Police Call Plus, published each year in 9 regional
 volumes by Hollins Radio Data, and sold at Radio Shack and
 larger book stores for under $13.  Police Call Plus 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.  A few pages of local airport and
 nonsensitive federal government frequencies are included.
 Selected business frequencies are listed, too, but without
 callsigns and other details.

 I highly recommend Richard Barnett's book, Monitor America,
 published by Scanner Master Corp.  A 3rd edition is
 available from Grove Enterprises
 for about $30.  It 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 Radio
 Communications Monitoring Association (RCMA), now defunt.
 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 Plus, 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.

 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 401 page third edition is available
 from Official Scanner Guides (P.O. Box 525-NS, Londonderry,
 NH 03053).  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 longstanding 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.
 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 a good
 book for this difficult to obtain information.

 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.


 Although national in circulation, local frequency
 information is sometimes available in Grove's Monitoring
 Times and the 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-

 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 information on CDROM instead.

 You can query FCC databases directly from this web page:

 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.

 The PerCon Spectrum CDROM sells for under $30 and contains
 a handful of fields for every FCC license in the US.
 However, Public Safety license information contained in the
 Winter 1996 Spectrum doesn't appear as up to date as in the
 1997 Police Call Plus.

 Spectrum works in DOS, Windows, and Mac environments.  One
 can try restricted sample searches of the Spectrum CD for
 free via PerCon's web page at .

 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.

 As I have already done for hundreds of radio enthusiasts,
 companies, government agencies, and organizations across
 the country since 1994, 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 a beautiful 11" by 17" scaled color map,
 protected by plastic.  The map is marked with transmitter
 sites, cities, highways, airports, military installations,
 national parks, etc.  See
 for a sample.

 RadioMap has been advertised monthly in Monitoring Times
 magazine since 1995.  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 $24.95 plus $5.00 shipping
 and handling.  For an additional $10.00, the deluxe report
 includes and extra index sorted by frequency and 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 $29.95 for standard or
 $39.95 for deluxe RadioMap report with histogram and
 additional index by frequency.  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.

                          Web Sites

 If you have access to the World Wide Web, you can visit
 dozens of sites with local frequency lists.  You can look
 up civilian aero frequencies for specific airports at:

 Other frequency web sites include:,, and

        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). (See "The Government Giveth, the
 Government Taketh Away", by Richard Prelinger, in
 Monitoring Times, July 1982.)

 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'.
 (See "AFIO and the FOIA", by Bob Grove, in Monitoring
 Times, September 1982.)

 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.

 Two way radio equipment formerly used by the armed forces
 often appears for sale at hamfests.  Less often, Secret
 Service and FBI radios appear there from time to time, too.
 When you see such equipment, look over the radio for a
 frequency label and write down the frequencies stamped on
 the crystals or channel elements.  Make note of any service
 or property tags which specify the agency or military base
 which used the equipment.

                         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), now out of business.  There
 are several regional scanner clubs, spun off from the
 former RCMA, which hold regular meetings.

 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 on the WWW page and from:

                   All Ohio Scanner Club
                   50 Villa Road
                   Springfield, OH 45503

                    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

   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

 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

 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.

 If you don't have a VOX recorder, consider a device like
 the NiteLogger II tape recorder controller, made by
 Benjamin Michael Industries.  It connects simply between
 scanner and recorder and contains sound activation
 circuitry to trigger the recorder.

 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 or P-Touch 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

 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.

 Another source of frequency information is as close as your
 nearest Radio Shack store.  Some Radio Shack stores make a
 local frequency list available to assist their scanner
 customers.  Be sure to ask.  Stores located in shopping
 malls almost always know the mall security frequencies.  I
 often check the frequencies programmed into the floor model
 scanners, too.

       Examine the Antenna to Determine Frequency Band

 You can often determine a transmitter's frequency band by
 the size and type of antenna used.

 The Police Call Plus book contains sketches of antennas.
 Antenna catalogs are crammed full with antenna pictures and
 specifications and they are usually free.  Contact Antenna
 Specialists (216-349-8400), Cushcraft (603-627-7877),
 Tessco (800-472-7373), Maxrad, Larsen Electronics (800-
 426-1656), and other companies in the land mobile 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 Radio Shack PRO-2035,
 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, another spectrum analyzer connected to a
 receiver IF stage, and a frequency counter for close-in

               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 earlier, 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

 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.


 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


                Grove Enterprises
                7540 Highway 64 West
                Brasstown, NC 28902.
                tel (828)837-9200
                order line (800)438-8155

                Official Scanner Guides
                P.O. Box 525-NS
                Londonderry, NH 03053.
                tel (603)432-2615
                order line (800)351-7226

                Scan America
                430 Garner Drive,
                Suffield, OH 44260-1557

                Scanner Master,
                PO Box 428
                Newton Highlands, MA 02161.
                telephone 1-800-722-6701.

Bob Parnass, AJ9S                              

User Contributions:

Comment about this article, ask questions, or add new information about this topic:


[ Usenet FAQs | Web FAQs | Documents | RFC Index ]

Send corrections/additions to the FAQ Maintainer: (Bob Parnass, AJ9S)

Last Update March 27 2014 @ 02:12 PM