The Broadcast License Store

What is an FM Translator or FM Booster Station?

FM Translators and FM Boosters are a low power service on the FM Broadcast Band (88 to 108 MHz) designed to complement the primary FM or AM service. This service was first created in 1970 to allow FM stations to provide supplementary service to areas in which direct reception of radio service is unsatisfactory due to distance or intervening terrain barriers (e.g. a mountain).

There are no multiple ownership limits on the number of translator and booster stations a single entity may own. Nor are they counted as FM stations for the purposes of the primary station ownership rule.

Translator stations simultaneously rebroadcast the signal of a primary AM or FM station on a different frequency. Those translator stations that provide service within the primary station's protected service area are classified as "fill-in" stations.

Fill-in translators can be owned by the main station or by an independent entity. Commercial non-fill-in translators are generally owned by independent entities, with certain exemptions, while noncommercial educational non-fill-in translator stations are generally owned by the primary station being rebroadcast.

Booster stations are essentially "fill-in" translator stations on the same frequency as the main station. Booster stations must be owned by the licensee of the primary FM station. Booster stations are also restricted in that the service contour of the booster may not exceed the protected service contour of the primary station at any azimuth.

* Translators or boosters may not originate programming
* A commercial fill-in translator may receive a primary station's signal via any terrestrial transmission method, including (but not limited to) microwave, phone, Internet and dedicated fiber optic cable. Satellite delivery is prohibited.
* The translator station can receive only one FM primary station.
* The maximum effective radiated power permitted for any translator station is 250 watts.
* The maximum effective radiated power for a booster station is 20% of the main station's maximum class power.
* A fill-in translator station must maintain its 60 dBu (1 mV/m) service contour within the 60 dBu contour of the primary station.
* FM booster call signs incorporate the call sign of the main station with the suffix-FM (booster number) added (e.g., KBDR-FM1)
* The service contour for a non-fill-in translator station may extend outside the primary station's service contour or, in some cases, lie wholly outside it.