How to Connect and
Back Panel Information
Refer to the drawing on page 5.
AUDIO OUTPUTS
Use the FIXED OUTPUT jacks on the rear panel to
feed program to a stereo control preamplifier or other
equipment which has its own volume control. The
front panel VOLUME control does not affect the loud-
ness of the tuner at the FIXED OUTPUT jacks. The out-
put level is a nominal 1 volt for 100% FM modulation.
Use the VARIABLE OUTPUT jacks to connect to
equipment such as a power amplifier or a tape recorder
where control of the volume at the tuner is desired. The
output at the VARIABLE OUTPUT jacks is a nominal 2.5
volts for 100% FM modulation. There is no difference in
the signal quality at either pair of output jacks.
Both pairs of OUTPUT jacks may be used simulta-
neously. The output impedance at both outputs is
very low so that long audio cables can be used with-
out a loss of high frequencies due to cable capacity.
CONNECTING AN FM ANTENNA
One of three antenna systems can be used: (1) an
outdoor FM antenna, or (2) an VHF-TV antenna, or (3)
the indoor dipole supplied.
An outdoor antenna is recommended for optimum
performance in all areas. In fringe (outlying) areas,
best results will be obtained with a highly directional
FM antenna used in conjunction with a rotator. If the
antenna uses a 300 ohm lead, connect it to the
ANTENNA 300 FM push connectors.
The coaxial cable of an unbalanced 75 ohm antenna
connects to the rear panel ANTENNA 75ft FM type F
coaxial connector.
An outside antenna system should not be located
in the vicinity of overhead power lines or other elec-
tric light or power circuits, or where it can fall into
such power lines or circuits. When installing an out-
side antenna system, extreme care should be taken to
keep from touching such power lines or circuits as
contact with them might be fatal.
A VHF-TV antenna can be effective when it is
designed for both FM and TV reception. Connect the
two leads from the VHF-TV antenna to the ANTENNA
300ft FM push connectors.
The flexible folded dipole antenna (300 ohm) sup-
plied with the MR 75 is for use in urban or high
strength signal areas. Connect the two leads from the
dipole to the ANTENNA 300 FM push connector.
The flexibility of the twin flat wire assembly permits
it to be placed under a rug, tacked behind the stereo
or placed in any other convenient location. In some
cases, it may be necessary to "position" the antenna
for best signal reception. This should be done before
it is permanently located.
Avoid locating the antenna next to other wires or
metal objects. Any indoor antenna may be ineffective
in houses having metal siding or metal foil insulation.
FM PRESELECTOR SWITCH
FM receivers can be overloaded by very large anten-
na input signals when the receiver is located very
near to a FM broadcasting station or when a high gain
directional antenna is used in a metropolitan area. An
example of overload is where a FM station can be tun-
ed in at two or more places on the dial. A preselector
tuned circuit is built into the MR 75 to prevent
overload.
The preselector may be switched into or out of the
FM RF circuit by a slide switch located on the rear
panel.
We recommend the FM PRESELECTOR switch be
used in the "out" position for all FM listening condi-
tions except where there is evidence of overload by
strong stations. In that case, the " i n " position will
protect against overload. For most stations there will
be no listening difference between the two switch
positions.
AM ANTENNA
For local and most moderately distant AM recep-
tion, the built-in ferrite loopstick antenna may be
used. The AM loopstick antenna is on a swivel base
and must be adjusted away from the chassis for best
reception. The illustration at the top of page six
shows examples of the many positions the AM anten-
na may be placed in. Try several positions until you
locate the best performing location for your listening
area.
Distant reception can be improved with the use of a
copper antenna wire 50 to 150 feet in length. Suspend
the wire in a straight line as high as possible. Attach
the wire at each end with suitable glass or ceramic in-
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