protected against output short-circuiting by a fuse, which is resettable by
disconnecting the unit from the +18 to +36 v DC supply.
With all connections made, the telephone can then be turned on and used as
normal - it is transmitting into a load impedance equivalent to a matched
passive antenna. The gains of the antenna transmitter and receiver are factory
set to compensate for the total attenuation between the telephone and the
antenna, mainly determined by the coaxial down-lead. Consequently, the
signal output level and frequency from the antenna is equivalent to that
radiating from a passive antenna mounted directly on the handset, subject to
the antenna transmitter being a linear device. Transmitter linearity is verified
with test protocols using an HP 8591 EMC analyser that also ensure there are no
spurious out of band emissions.
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General