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TUCoPS :: Radio :: how2find.txt

How do you find those Scanner Frequencies? by Bob Parnass

    [last updated August 10, 1993]

    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.


   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

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

                           - 3 -


   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-

   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-

   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

   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

                           - 6 -

                       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-

   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.

   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-

   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

                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-

   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



 9. XYZ is a pseudonym for the actual licensee name.

                           - 11 -


   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.


   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

                       Copyright 1994,  Bob Parnass, AJ9S
         AT&T Bell Laboratories  - - (708)979-5414

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