47 CFR FCC Part 73 Certification Testing of Radio Broadcast Services
Part 73 discusses AM, FM, and TV broadcast stations in regards to standardizing procedures and test methods. As a leader in RF regulatory compliance testing, Keystone Compliance recognizes the requirements needed for wireless radio manufacturers. Meeting the ETSI, FCC, and other wireless testing specifications can be challenging. Not only do we understand the challenges, but we help guide companies through the process.
Keystone’s radio testing engineers streamline the process and assist companies to achieve the compliance they require. Furthermore, our accurate test reports are delivered quickly using our “four-eyes” approach. Meaning that multiple technicians review each report, ensuring that all the information required is present. From concept through compliance, Keystone meets all of our customer’s needs under one roof.
Summary of AM, FM, and Television Broadcasting Systems
AM Broad Stations
AM broadcast band frequencies extend from 535 to 1705 kHz. The channel is occupied by the carrier and the upper and lower sidebands of an AM broadcast signal.
An application for authority to install a broadcast antenna must specify a definite site. The application must also include full details of the antenna design and expected performance.
A clear channel is one on which stations are assigned to serve wide areas. These stations are protected from objectionable interference within their primary service areas. There are four classes of AM broadcast stations.
Class A Station: A Class A station is an unlimited time station that operates on a clear channel. This station also renders primary and secondary service over an extended area from its transmitter.
Class B Station: These operate with a minimum power of 0.25 kW and a maximum power of 50 kW.
Class C Station: A Class C station is a station operating on a local channel. They are designed to render service only over a primary service area that is reduced as a consequence of interference.
Class D Station: A Class D station operates either daytime, limited time, or unlimited time with nighttime power less than 0.25 kW and an equivalent RMS antenna field of less than 107.5 mV/m at 1 kilometer.
FM Broadcast Stations
The FM broadcast band consists of a radio frequency spectrum between 88 MHz and 108 MHz. The broadcast band is divided into 100 channels of 200 kHz each. For convenience, the frequencies are given a numerical value designation.
Applications are filed to construct new FM broadcast stations at communities and channels contained in the wireless standard.
The United States is divided into three zones as follows:
Zone I: consists of the portion of the United States within the Albers Equal Area Project Map. The zone encompasses states such as Ohio, Pennsylvania, Illinois, Virginia, and other North-Eastern states.
Zone I-A: consists of Puerto Rico, the Virgin Islands, and a portion of California south of the 40th parallel.
Zone II: encompasses Alaska, Hawaii, and the rest of the United States not located in the zones mentioned above.
TV Broadcast Stations
This subpart of the FCC part 73 standard contains the rules and regulations governing TV broadcast stations. This also includes the engineering standards for non-commercial education and other various stations. Lastly, where indicated, the 47 CFR FCC standard also covers low-power TV and TV translator stations in the United States.
The TV broadcasting standards have divided the United States into three zones.
Zone I: consists of states such as Ohio, Pennsylvania, Illinois, Virginia, and other North-Eastern states. This zone is very similar to zone I of the FM broadcast stations.
Zone II: consists of that portion of the United States which is not located in either Zone I or Zone III, and Puerto Rico, Alaska, Hawaiian Islands, and the Virgin Islands.
Zone III: Zone III consists of a southern portion of the United States in the Albers Equal Area Projection Map. The zone begins on the east coast of Georgia consisting of arcs ending at the United States-Mexican border.
Scope of Wireless Intentional Radiator Testing of FCC Broadcast Stations
The Federal Communications Commission may require applicants or licensees to write a statement of fact relevant to a determination of whether an application should be granted, denied, or revoked. Initial licenses are generally issued for a period running until the date specified per every state in the FCC standard. Both radio and TV broadcasting stations are usually renewed for eight years.
Each broadcast station is licensed to the principal community or other political subdivision which it primarily serves. Furthermore, each station must maintain a local telephone or toll-free number in its community of license.
FCC Broadcast stations are operated for tests and maintenance of their transmitting systems on their assigned frequencies using their licensed operating power and antennas during their authorized hours of operation without specific authorization from the FCC. Licensees of AM stations may operate for tests and maintenance during the hours from midnight local time to local sunrise. However, this only applies if no interference is caused to other stations maintaining a regular operating schedule within such a period.
Expert 47 CFR Part 73 Broadcast Systems Wireless Testing
Keystone has a full lab of test equipment which permits us to provide short lead times on scheduling. Our team strives to give our customers more time and energy on product development instead of testing. Keystone Compliance can accommodate fixed, mobile and portable devices of all sizes.