Listening to the MR 78 Tuner
MONOPHONIC FM PROGRAMS
To receive monophonic FM broadcasts set the:
MODE switch to MONO
MUTING switch to DISTANT
FILTER switch to OUT
SELECTIVITY switch to NORMAL
Adjust the tuning knob to the desired station. The
station is properly tuned when the TUNING meter
pointer comes to rest anywhere over the black area
on the meter scale. While tuning across the dial you
may notice movement of the tuning meter pointer
without hearing a station. This is caused by a station
so weak or distant that it does not over-ride the back-
ground noise. Extremely weak stations may be heard
by setting the MUTING switch to OUT.
Rotate the directional antenna for best reception as
indicated by a maximum pointer deflection on the
SIGNAL STRENGTH meter and a minimum pointer
deflection on the MULTIPATH meter. Then adjust the
VOLUME control to the desired listening level.
STEREO FM PROGRAMS
If you wish the tuner to automatically switch be-
tween stereo and mono broadcasts, set the:
MODE switch to STEREO AUTO
MUTING switch to DISTANT
SELECTIVITY switch to NORMAL
In this mode of operation, setting the FILTER switch
to position 1 or 2 will reduce noise on weak stereo
stations.
When the STEREO indicator is lighted, the station is
broadcasting a 19,000 Hz pilot signal for stereo and the
MR 78 will automatically switch to stereo. If a station
is not transmitting the 19,000 Hz pilot for stereo,
the STEREO indicator will remain off and the tuner
will automatically switch to mono.
When the MODE switch is set to STEREO ONLY,
monophonic broadcasts and background noise be-
tween stations will be muted. Broadcasts with the
19,000 Hz pilot signal will activate an automatic stereo
sensing circuit. The stereo indicator will light and the
broadcast will be heard.
USING VARIABLE SELECTIVITY
With the increasing number of stations crowding
the FM broadcast band, an FM tuner with variable
selectivity has become a necessity. Local stations are
received best with the SELECTIVITY switch in the
NORMAL position. This position gives the lowest
distortion. Use this position for critical taping of live
local broadcasts.
If you experience "crosstalk" or "splatter" on a sig-
nal from a strong adjacent or alternate channel, use
the NARROW position of the SELECTIVITY switch
to reduce the interference.
The "SUPER NARROW" SELECTIVITY position is
used to find clear signals from distant stations that
cannot be heard from ordinary tuners.
When you use SUPER NARROW SELECTIVITY,
you may find that reception of distant stations adja-
cent to a channel transmitting SCA (background music
programs) is difficult. Stations transmitting SCA
often have wide sidebands. These sidebands spill over
onto adjacent channel stations. If you tune the MR 78
to one of the sidebands of the SCA transmission, you
may be able to hear the background music program
simultaneously with the regular program.
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