Ramsey Electronics FM100BWT User Manual page 12

a. The transmitter must NEVER be tuned to a frequency above 108 MHz,
specifically the band 108-121.94 MHz, FCC Rule 15.205 lists this band as
restricted, due to potential interference with aircraft navigation equipment.
b. The "bandwidth" of your transmission is limited to 200 KHz, centered on
the actual operating frequency. Since 200 KHz is enough spectrum space
for several different FM stations, this is a "generous" limitation designed to
accommodate cruder FM devices. Properly built and adjusted, the
FM100B kit operates well within this limit. In fact, its signal should sound
no "wider" than any other FM station when listening on an ordinary FM
radio.
c. FCC Rule 15.215(a) says: "Unless otherwise stated, there are no
restrictions as to the types of operations permitted under these sections."
This general provision appears to leave you free to use your FM stereo
transmitter in a manner similar to operations of an FM broadcasting station,
or to use it for any other non-interfering, practical application.
d. FCC Rule 15.5: General conditions of operation: "(b) Operation...is
subject to the conditions that no harmful interference is caused and that
interference must be accepted that may be caused by the operation of an
authorized radio station, by another intentional or unintentional radiator, by
industrial, scientific and medical equipment, or by an incidental radiator.
(c) The operator of a radio frequency device shall be required to cease
operating the device upon notification by a Commission representative that
the device is causing harmful interference."
e. The most specific FCC regulation of 88-108 MHz FM Broadcast band
unlicensed operation is that the "field strength" of the signal must not
exceed 250 microvolts/meter at a distance of 3 meters from the transmitter
(FCC rule 15.239). If you have any concern about this emission limit, have
your device checked by a technician with accurate measuring equipment.
Remember that the "field strength" of a signal is determined as much by
the antenna as by the RF output of the transmitter itself.
FM100B • 12