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. 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. It is posted twice monthly on the USENET groups rec.radio.scanner, alt.radio.scanner, and rec.radio.info. It is also available electronically from the rec.radio.scanner ftp archive on the official USENET FAQ library ftp://rtfm.mit.edu/pub/ group/rec.radio.scanner. 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: Books Magazines 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 Summary Addresses Books 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 http://www.grove-ent.com 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. Magazines Although national in circulation, local frequency information is sometimes available in Grove's Monitoring Times and the sensationalistic Popular Communications magazines. 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. 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: http://www.fcc.gov/searchtools.html 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 http://www.perconcorp.com/db_srch.htm . 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 http://www.megsinet.com/~parnass 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: http://www.airnav.com/airports/. Other frequency web sites include: http://w5gb.nmsu.edu/kc5kto/, http://www.fordyce.org/scanning/, and http://www.scannerway.8m.com. 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 http://aosc.rpmdp.com 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 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. 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 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. 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 business. 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 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 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 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 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 parnass@bell-labs.com User Contributions:
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