McIntosh MR 78, Руководство пользователя

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to either LOCAL or DISTANT position for muting.
Weak stations that may not override noise and inter-
ference are also suppressed by the muting. In the
OUT position, the muting is turned off. This allows
tuning of weak stations, but the noise and interference
will be present.
The MUTING FUNCTION indicator lights amber
whenever the MUTING switch is set to DISTANT or
LOCAL It will extinguish when the MUTING switch
is set to OUT.
FILTER SWITCH and FUNCTION INDICATOR
The FILTER SWITCH reduces noise on weak stereo
stations.
Position 1 reduces noise by approximately 10 dB.
Position 2 reduces noise by approximately 20 dB.
The FILTER FUNCTION indicator lights green when-
ever the FILTER switch is set to 1 or 2. It does not light
when the FILTER switch is set to OUT.
SIGNAL STRENGTH/MULTIPATH SWITCH AND
METER
The SIGNAL STRENGTH/MULTIPATH meter can
be switched to indicate either relative signal strength
or relative amount of multipath interference. With
METER switch set to SIGNAL STRENGTH, greater
pointer deflection indicates a stronger signal.
With the METER switch set to MULTIPATH, there
is little or no multipath interference when the meter
indication remains steady and at the left end of the
scale. If there is severe multipath interference, the
meter indication will follow the audible signal in much
the same manner as a VU meter. When the receiving
antenna is rotated to minimize multipath interference,
the meter indication will decrease and become steady.
If the multipath interference is eliminated, the meter
indication will be near zero and steady.
SELECTIVITY SWITCH AND INDICATOR
The SELECTIVITY switch allows stereo reception
even under severe receiving conditions. Setting the
SELECTIVITY switch to NORMAL connects a very low
distortion 8-pole Rimo filter in the IF circuit. Use the
NORMAL position of the SELECTIVITY switch for
listening to local broadcasts.
Setting the SELECTIVITY switch to NARROW adds
a sharp 8-pole Rimo filter to the NORMAL IF filter to
yield a low distortion (less than 0.2%), highly selective
16-pole composite IF filter. Use the NARROW posi-
tion of the SELECTIVITY switch to reduce any inter-
ference during the reception of distant stations.
Setting the SELECTIVITY switch to SUPER NAR-
ROW adds a 4-pole 4-zero crystal filter to the two
previously mentioned filters. Use the SUPER NARROW
position to receive stations from distant cities which
are on channels adjacent to local stations. There may
be usable signals never heard before with ordinary
FM tuners.
The SELECTIVITY indicator lights blue. The IHF
Adjacent Channel Selectivity characteristics are:
NORMAL 7 dB; NARROW 22 dB; and SUPER NA-
ROW 55 dB.
SECONDARY CONTROLS
On the top of the chassis behind the front panel is
the DIAL SCALE INTENSITY Switch and ANTENNA
MATCH SELECTOR switch.
DIAL SCALE INTENSITY SWITCH
Adjust the brightness of the dial lights by means of
this switch. Set the switch to BRIGHT for maximum
panel light; set the switch to DIM for subdued dial
light.
ANTENNA MATCH SELECTOR SWITCH
Under most conditions the ANTENNA MATCH
SELECTOR switch should be set to HIGH GAIN ANT.
position. Only in extreme fringe areas or when using a
low-gain (indoor) antenna should this switch be set
to LOW GAIN ANT. position. When set to LOW GAIN
ANT. position, background noise on weak stations
may be reduced.
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