You can search for stations with an exact frequency or you can search by an approximate frequency.

Valid FM frequencies in the U.S. range between 88.1 MHz and 107.9 MHz and are spaced every 0.2 MHz. Valid AM frequencies are betwen 530 kHz and 1720 kHz and are spaced every 10 kHz.

Approximate searches will match FM frequencies less than 1.0 MHz from the frequency entered and AM frequencies less than 100 kHz from the frequency entered. Note that entering an AM or FM frequency will override selection of "Only AM" or "Only FM" stations.