What's in a name? The callsign will give you an idea of how old the license is, as well as the type of radio service. For example, in the US, radio calls (for all services) are limited to starting with AAA-ALZ, KAA-KZZ, NAA-NZZ, and WAA-WZZ. This is by international treaty. An excellent discussion of callsign history may be found here. The Federal Communications Commission (FCC) constructs callsigns in different formats to reflect various radio services.

1. Commercial TV and radio stations have K- and W- calls of four letters (example: KLAX, LA; WBBJ, Chicago). The former is for stations west of the Mississippi River, and the latter is for stations east of the river. There are some exceptions, including some older stations with three letter calls. WKY in Oklahoma City is such a station.

2. In the amateur service, the number tells the location of the initial station, and length of call tells the initial operator class. This can be confusing since an amateur radio license serves as both a station and operator license. My call, K5DMI, would suggest that I live in the 5th call territory (AR-LA-MS-OK-TX) and that I'm either a techician or general class holder. Both statements only reflect what and where I was when issued in January, 1999. I've lived in Missouri, 0-land, and now Tennessee, 4-land, but I'm not required to change calls when moving. Even though I hold a general license, K5DMI is a vanity call, issued to me by request since it was available. My original call, KC5DMI, reflected my location and license class. The 1x3 format issued to technicians and generals had been exhausted for all FCC districts in 1999.. When the FCC opened the vanity call program, thousands of amateurs were able to request 1x3 calls (and other classes) that were not available under the sequential (automatic) callsign system.

3. For public service stations, the older licenses are in Kxx### format; the most recent licenses are in Wxxx### format. Memphis is a good example. KIC306, no longer maintained, was the VHF call for the police department from 1950 to the mid-1990s, even though the UHF system went online around 1973. The UHF system was KUO982. The original trunked system is WPAJ881. Also keep in mind the call signs that I list are for the mobile repeater, not mobile, fixed base, and other types of stations. It's possible that an agency will hold 3 or more licenses for the same frequency!

Station Identification of public service licensees is a hobby in itself. The FCC has different requirements for various radio services. Pilots, for example, normally identify their license with each transmission (N36TB requesting permission for takeoff...or possibly truncated with 36TB). Have you ever noticed the funny characters listed on aeronautical maps near VORs? That's the Morse ID for the VOR because that's how pilots can be certain that they've tuned in the correct VOR (.--- .-.. -. for JLN, Joplin). Amateurs are required to identify by call every 10 minutes and at the end of a conversation. How we ID depends on our mode of operation. We may send a Morse ID, verbally announce it, or send a data burst containing the call. Public safety agencies have considerable leeway. Some have an automatic Morse ID every 15 minutes, and some verbally announce the ID after an announcement (such as all points bulletin). What's really ironic is that Morse code is not used much beyond amateur communications these days, but every trunked system I've monitored has an automatic Morse ID! Talk about deja vu.

Send comments to jalexand@alumni.ou.edu.