PANLOC BUTTONS
At the bottom of the front panel corners are the
PANLOC buttons. After a tuner is installed on the
PANLOC bracket, pressing the PANLOC buttons
will lock the tuner firmly in position. Depressing
the PANLOC buttons (as with a ballpoint pen) will
release the tuner. The tuner can then be slid for-
ward to the inspection and adjustment position.
The PANLOC system gives absolute ease of in-
stallation, operation and maintenance.
SECONDARY CONTROLS
On the top of the chassis behind the front panel
are three secondary controls. They are MUTING
adjust, AM SENSITIVITY, and DIAL SCALE IN-
TENSITY.
MUTING
The MR 73 ultrasonic muting circuit suppresses
all noise between stations. It suppresses all weaker
stations not strong enough to override the back-
ground noise.
The muting threshold setting determines the
strength of the signal which can be heard with
muting in operation. The muting threshold is care-
fully adjusted to optimum at the factory using pre-
cision test instruments.
If it is found necessary to adjust the muting
threshold, turn the MUTING ADJ to the LEFT
(counterclockwise) to lower the muting threshold.
This allows weaker noisier stations to be heard
at the MUTING IN setting. Turn the control to the
RIGHT (clockwise) to raise the muting threshold.
This allows only the more powerful stations to be
heard at the MUTING IN setting.
AM SENSITIVITY
When the AM SENSITIVITY switch is in the
LOW position the noise between stations is re-
duced. The RF gain is not as great in the low
position.
DIAL SCALE INTENSITY
Adjust the brightness of the dial panel lights by
means of this switch. Set the switch to BRIGHT
for maximum panel light. Set the switch to DIM
for lower dial light.
Listening to the MR73
LISTENING TO AM
Turn the MODE SELECTOR switch to AM. Turn
the tuning knob to the desired station. The SIGNAL
STRENGTH meter will indicate the relative strength
of the particular AM station being received.
Adjust the VOLUME control to desired listening
level. If the fixed AUDIO OUTPUT jacks are used,
the tuner VOLUME control will not affect volume.
LISTENING TO MONOPHONIC FM
Turn the MODE SELECTOR to FM MONO to
listen only to monophonic FM.
If you wish to have the MR 73 automatically
switch to a stereo broadcast, set the MODE SE-
LECTOR to FM.
Turn the STEREO-FILTER to OUT.
Turn the MUTING to IN.
Turn the tuning knob to the desired station. The
station is properly tuned when the FM TUNING
meter pointer comes to rest anywhere in the black
area of the meter scale. While tuning across the
dial you may notice movement of the tuning meter,
without hearing a station. This is caused by a sta-
tion so weak that is does not over-ride the back-
ground noise. With ultrasonic muting in operation
signals that are marginal are automatically sup-
pressed. To hear these weaker stations, turn the
MUTING switch to OUT. Usually the listening
quality will be rather poor due to the background
noise.
Rotate the directional antenna for best reception
as shown by the SIGNAL STRENGTH and MULTI-
PATH indicators.
Adjust the VOLUME control to desired listening
level. If the fixed AUDIO OUTPUT jacks are used,
the tuner VOLUME control will not affect volume.
LISTENING TO STEREO FM
Repeat the same procedure as for monophonic
FM but turn the MODE SELECTOR to FM.
When the STEREO indicator is lighted, the sta-
tion is broadcasting a 19,000 Hz carrier for stereo
and the MR 73 will automatically switch to stereo.
If a station is broadcasting monophonic FM pro-
gram, the STEREO indicator will remain off and
the tuner will automatically switch to mono.
Adjust the VOLUME control to desired listening
level. If the fixed AUDIO OUTPUT jacks are used,
the tuner VOLUME control will not affect volume.
The STEREO FILTER reduces noise on weak sta-
tions.
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