Sec. 2.987  Measurements required: Modulation characteristics.

    (a) Voice modulated communication equipment. A curve or equivalent 
data showing the frequency response of the audio modulating circuit over 
a range of 100 to 5000 Hz shall be submitted. For equipment required to 
have an audio low-pass filter, a curve showing the frequency response of 
the filter, or of all circuitry installed between the modulation limiter 
and the modulated stage shall be submitted.
    (b) Equipment which employs modulation limiting. A curve or family 
of curves showing the percentage of modulation versus the modulation 
input voltage shall be supplied. The information submitted shall be 
sufficient to show modulation limiting capability throughout the range 
of modulating frequencies and input modulating signal levels employed.
    (c) Single sideband and independent sideband radiotelephone 
transmitters which employ a device or circuit to limit peak envelope 
power. A curve showing the peak envelope power output versus the 
modulation input voltage shall be supplied. The modulating signals shall 
be the same in frequency as specified in paragraph (c) of Sec. 2.989 for 
the occupied bandwidth tests.
    (d) Other types of equipment. A curve or equivalent data which shows 
that the equipment will meet the modulation requirements of the rules 
under which the equipment is to be licensed.