There are two fields in the AM Engineering Database and the AM Query which involve the class of station. They are:

• The Domestic Class (or class of the station with respect to other U.S. stations), which is generally the class of station defined in Section 73.21

• The Region 2 Class, which is generally the class of station as defined in the Region 2 [Western Hemisphere] AM Agreement. This class also corresponds to the class in the 1984 U.S.-Canadian AM Agreement and the 1986 U.S.-Mexican Agreement.

Classes for U.S. Stations

In MM Docket 87-267, the Commission reclassified all domestic [United States] AM stations. These classes are A, B, C, and D. Generally, all U.S. records will have both a Domestic Class and a Region 2 Class. For U.S. stations, the Region 2 Class can be derived from the Domestic Class. Therefore, we explain how to derive the Domestic Class first. The AM band frequencies are divided into three categories: Clear, Regional, and Local channels. The allowable classes depend on a station's frequency, in addition to other variables. On the Clear channels certain stations are specifically classified as Class A stations or as Class B stations. The other stations have their class determined by the frequency.

Classes of AM stations are defined as follows:

• Class A Station. A Class A station is an unlimited time station (that is, it can broadcast 24 hours per day) that operates on a clear channel. The operating power shall not be less than 10 kilowatts (kW) or more than 50 kW.

• Class B Station. A Class B station is an unlimited time station. Class B stations are authorized to operate with a minimum power of 0.250 kW (250 watts) and a maximum power of 50 kW. (If a Class B station operates with less than 0.250 kW, the RMS must be equal to or greater than 141 mV/m at 1 km for the actual power.) If the station is authorized to operate in the expanded band (1610 to 1700 kHz), the maximum power is 10 kW.

• Class C Station. A Class C station is an unlimited time station that operates on a local channel. The power shall not be less than 0.25 kW nor more than 1 kW. Class C stations that are licensed to operate with 0.100 kW may continue to operate as licensed.

• Class D Station. A Class D station operates either daytime, limited time, or unlimited time with a nighttime power less than 0.250 kW and an equivalent RMS antenna field less than 141 mV/m at 1 km for the actual power. Class D stations shall operate with daytime powers not less than 0.250 kW nor more than 50 kW. NOTE: If a station is an existing daytime-only station, its class will be Class D.

Clear, Regional, and Local Channels Steps to Follow to Determine the Domestic Class

If you don't want to use the easy way to determine the station's domestic class (via the AM Query), here's the steps to follow to determine the class. A table of which frequencies are Clear, Regional, or Local is included below.

1. Determine which frequency the station is on (or is proposing) and also determine whether the station is one of the ones with a specifically defined class (see the right column in the table below). Following is a list, by frequency, which lists the specific Class A or Class B stations, along with the available classes for the other stations:

2. If the station is specifically listed in the table on the actual frequency in the actual city, then the Domestic Class for the station is defined on the above list. (Call sign changes don't matter, the classification remains with the station, not the call sign.)

Note that all the former Class I-N stations are located in Alaska, while all the former Class I-A and former Class I-B stations are located only in the coterminous 48 states. Only in Alaska might it be possible to assign new Class A stations.

3. If the station of interest is not specifically listed above on the actual frequency in the actual city, the Domestic Class must be determined from the available classes for the frequency:

• If the available classes are A, B, and D, then the Domestic Class will be Class B. It cannot be Class A because all of the Class A stations are listed above. It cannot be Class D because the Commission will not authorize new Class D stations (unless the station had been previously licensed as Class B and the station is downgrading to its nighttime operation to Class D.)

  If the station is an existing daytime-only station, the class will be Class D.

• If the available classes are B and D, then the Domestic Class will be Class B. It cannot be Class D because the Commission will not authorize new Class D stations (unless the station had been previously licensed as Class B and the station is downgrading to its nighttime operation to Class D.)

  If the station is an existing daytime-only station, the class will be Class D.

• If the available classes are B and C, then the Domestic Class will generally be Class C. However, if the station is in Alaska, Hawaii, Puerto Rico or the U.S. Virgin Islands, then the Domestic Class is Class B.


4. The rules adopted in MM Docket 97-267 allow existing unlimited-time Class B (formerly Class II and III) stations to voluntarily reclassify their nighttime operations to Class D if they find it advantageous to do so. This is the ONLY instance where new Class D stations are allowed. [ Existing Class D daytime-only stations will remain so classified. ]

An AM station can have only one licensed class. The licensed daytime class cannot be different than the licensed nighttime class. If the station is downgrading its nighttime operation to Class D, then the construction permit will have a different class than the license. Once the construction permit becomes licensed as Class D, then any licensed daytime record will be changed to Class D also.

The Region 2 Class

Once the Domestic Class has been obtained, the Region 2 Class is easily determined:

Old to New Class Conversions

Because the old classifications for AM stations will be encountered in older documents pertaining to AM radio, we have provided this conversion table for your convenience:

This page is located at http://www.fcc.gov/mb/audio/amclasses.html