MENTOR
RADIO
CO.
Very low loss coaxial cables are thicker, heavier and stiffer and are therefore harder to
work with and install. For lengths that exceed 150 feet (50 meters), consider remote op-
eration.
The coaxial cable should be terminated at the radio end by a “UHF” type connector, some-
times called a “PL259”. The connector should be installed by a person skilled in this op-
eration. This connector plugs into the mating connector (type “SO239”) on the rear of the
MB—be sure to turn the ring with the internal threads CW until the connection is firmly
made. At the antenna end, if there is no similar connector, any unshielded center lead
should be no longer than 2 inches (5 cm.)
A number of acceptable microphone choices exist. Whether of the hand held aircraft style
or a table or desk “dispatchers” style, a transistorized dynamic microphone element is
much preferred over the older carbon type elements which have poorer performance and
shorter lives. Many readily available microphones, such as a “condenser”, un-amplified
dynamic and ceramic types will
not
work with the model MB. The microphone plug must
be of the 3/16 inch diameter 2-circuit type, as commonly used in aircraft. The microphone
plug should be inserted completely and firmly into the microphone jack at the lower left of
the front panel of the MB.
If the Model MB is to be operated remotely, refer to additional installation instructions that
accompany the various kinds of remote accessory equipment.
