FRONT PANEL INDICATORS
The MR 75 has three dial scales: 1. AM - marked 550
to 1600 kHz; 2. FM - marked 88 to 108 MHz; 3. Logging
scale 0 to 100.
As the tuning knob is turned, the pointer moves
across the dial. There are two LEDs on the pointer.
When you have selected FM, one LED glows behind
the FM scale, on AM the other glows behind the AM
scale.
The Logging Scale is useful for retuning to your
favorite station with great accuracy.
TUNING KNOB
The Tuning Knob selects AM or FM stations. An AM
station is tuned in correctly when the vertical column
signal strength indicator shows a maximum. An FM
station is correctly tuned when the center bar in-
dicator at the bottom of the signal strength column il-
luminates and the signal strength display is at a max-
imum. There are indicators and - on each
side of the FM center bar. These light as you ap-
proach FM stations and indicate if you are above ( + )
or below ( - ) the station. When the center tuning bar
lights, the FM AFL (automatic frequency lock) circuit
is active and the tuner is locked to the FM station.
This locked condition will give the best FM reception
with lowest background noise, lowest distortion and
best stereo separation.
Because of the locking action of the AFL circuit,
the Tuning Knob can be tuned mechanically slightly
away from the frequency of the FM station without
detuning the MR 75. This makes tuning the MR 75 very
easy but can cause the MR 75 to not return to the FM
station when power is turned off and on again. This
condition can be avoided if, when tuning in a station,
you stop turning the Tuning Knob as soon as the
center bar indicator lights. Then the MR 75 will return
to the same station when power is turned on again.
INPUT INDICATORS
At the bottom right of the tuning dial area are three
LED lamps; two indicate the status of the SELECTOR
switch. The illuminated LED indicates whether AM or
FM is selected.
The remaining LED marked "mute" indicates when
the mute switch is in the "on" position.
SOLID STATE TUNING INDICATOR
The MR 75 utilizes an all solid state tuning in-
dicator. Fourteen LEDs make up the display, which
consists of four bars and 10 small dots.
The bar at the top indicates reception of a FM
stereo multiplex (MPX) station. The 10 little dots ar-
ranged in a vertical column indicate relative station
signal strength for AM or FM. The three bars at the
bottom of the display indicate if you are tuned above
( + ), below ( - ) , or right on-station when receiving FM.
When tuning a FM station, the proper adjustment is
when only the center on-station vertical bar indicator
lights.
HEADPHONE JACK
A HEADPHONE jack is provided to drive low im-
pedance dynamic headphones from an internal power
amplifier.
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