31. We believe that frequencies in the 5250-5400 kHz range may be useful for
completing disaster communications links at times when the 3 and 7 MHz bands
are not available due to ionospheric conditions, and appreciate the desire
of the amateur radio community to assist with disaster communications. At
the same time, since the majority of the affected users are Federal
Government licensees with homeland security responsibilities, we give
considerable weight to the concerns NTIA has expressed about the potential
for interference to these users. Thus, we conclude that it is not
reasonable to grant ARRL's original request for the whole of the 5250-5400
kHz band. However, as indicated above, NTIA has reviewed its assignments
and has found that 5 channels are lightly used and could be used on a
secondary basis by amateur stations. While we recognize that these five
channels will not give the amateur service the 150 kilohertz of spectrum in
the 5000 kHz range it originally asked for or the flexibility to use
multiple transmission modes, this appears to be the best compromise
available to give the amateur service access to new spectrum while assuring
the Federal Government agencies that their use is protected. We also concur
with NTIA's basic proposals that amateur service operations on these
channels be limited to SSB-SC modulation, upper sideband voice transmissions
only, with power not to exceed equivalent of 50 W PEP transmitter output
power into an antenna with a gain of 0 dBd, or 50 W e.r.p. These operating
rules will decrease the interference potential between amateur stations and
Federal Government users. Accordingly, we are amending sections 2.106, and
97.303 of our rules to provide a secondary allocation to the amateur service
on the channels 5332 kHz, 5348 kHz, 5368 kHz, 5373 kHz and 5405 kHz as
specified by NTIA, and to require that amateur operations be limited to an
effective radiated power (e.r.p.) of 50 W, and emission type 2K8J3E, upper
sideband voice transmissions only centered on each frequency. For the
purpose of computing e.r.p. the transmitter peak envelope power will be
multiplied with the antenna gain relative to a dipole or the equivalent
calculation in decibels. A half wave dipole antenna will be presumed to
have a gain of 0 dBd. Licensees using other antennas must maintain in their
station records either manufacturer data on the antenna gain or calculations
of the antenna gain. In addition, because we are permitting amateur
stations to transmit on 5 discrete frequencies and limiting the transmission
mode to single sideband only, dividing the band into smaller sub-bands to be
used for other emission types is not practical or necessary. Lastly, we
will permit these frequencies to be used by amateur service licensees with a
General Class, Advanced Class, or Amateur Extra Class operator license. We
believe that the limited number of frequencies and the emission restriction
will protect against interference to primary service operations.
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