McIntosh MR66, Руководство пользователя

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caused by a station so weak or distant that it
does not over-ride the background noise.
With ultrasonic muting in operation a noisy
station of this type is automatically rejected.
To hear these weaker or distant stations, turn
the FM FUNCTION switch to MUTE OUT.
Usually the listening quality of a station of
this type will be rather poor due to the weak
signal and background noise. (See section
titled "MUTING ADJUSTMENTS.")
If two FM stations are very close together
on the dial, the AFC action may tend to cap-
ture and hold the stronger of the two sta-
tions. Turn the AUTO FREQ CONTROL to the
left (counterclockwise) to reduce AFC in
order to tune in the weaker station. The
quality of the FM program is unaffected by
the setting of the AUTO FREQ CONTROL.
(See section titled "AUTO FREQ CONTROL.")
STEREOPHONIC AM-FM RECEPTION
Turn the AM FUNCTION switch to BROAD,
the MODE SELECTOR switch to STEREO, and
the FM FUNCTION switch to MUTE IN. Set
the AUTO FREQ CONTROL to any setting
between MIN and MAX. Allow a warmup time
of approximately 30 seconds.
Tune the AM dial to the AM station broad-
casting one channel of the stereophonic
program. Then tune the FM dial to the FM
station broadcasting the other channel of the
same stereophonic program.
If 10KC squeal interference is present in
the AM channel, turn the AM FUNCTION
switch to the MED 2 position. This places the
10KC filter in operation.
STEREOPHONIC FM MULTIPLEX
RECEPTION
The Mclntosh MA6 FM Multiplex Adapter
must be properly installed in the MR66 in
order to receive FM Multiplex Stereophonic
programs. (See Section under "CONNECT-
ING" titled "STEREOPHONIC FM MULTI-
PLEX.")
Turn the AM FUNCTION switch to MULTI-
PLEX FM, the MODE SELECTOR switch to
STEREO and the FM FUNCTION switch to
MUTE IN. Set the AUTO FREQ CONTROL to
any position between MIN and MAX. Tune
the FM dial to the station broadcasting FM
Multiplex Stereo. Satisfactory FM Multiplex
Stereo reception requires approximately 10
times as much signal from the antenna com-
pared to equivalent FM monophonic recep-
tion. Monophonic installations that were
satisfactory with an indoor FM antenna may
require an outside or directional FM antenna
for equivalent FM Multiplex reception.
ADJUSTMENTS
MUTING THRESHOLD
The MR66 ultrasonic muting circuit sup-
presses all noise between stations. It also
suppresses all weaker stations not strong
enough to over-ride the background noise.
The muting threshold setting determines
the strength of the signal which can be
heard with muting in operation. The muting
threshold is carefully adjusted to optimum at
the factory using precision test instruments.
Casual adjustment of the muting threshold
is not recommended.
If it is found necessary to adjust the
muting threshold, use the SQUELCH ADJ
control on top of the MR66 chassis. Turn the
SQUELCH ADJ control to the RIGHT (clock-
wise) to lower the muting threshold. This
allows weaker, noisier stations to be heard at
the MUTE IN setting. Turn the SQUELCH
ADJ control to the LEFT (counterclockwise) to
raise the muting threshold. This allows only
the more powerful stations to be heard at
the MUTE IN setting.
AM SIGNAL STRENGTH INDICATOR
The AM Signal Strength indicator pointer
normally should rest on the zero scale mark-
ing with AM operating but no station tuned in.
To adjust, turn the AM FUNCTION switch
to BROAD and the MODE SELECTOR switch
to MON AM. Turn the AM tuning dial until the
pointer is not on or near a station. Remove
the AM antenna from the back panel antenna
terminals. (This eliminates any noise or
interference which may cause a slight meter
deflection.) Rotate the red AM MTR ADJ
thumb wheel control (under the left dial
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