Yamaha CR-840 Owner's Manual page 10

The T-type antenna provided with yourCR-840 is
adequate only in high signal strength areas and
under favorable conditions. In other cases, an
external multi-element FM antenna is needed. If
you cannot obtain satisfactory reception with the
T-type antenna, this is an indication that you need
an external FM antenna. To ensure the very best
results, a motor-driven antenna assembly with
remote control of its orientation is ideal, but the
CR-840 has sufficient sensitivity to operate well
with a fixed antenna. The external antenna should
perferably be located fairly close to the CR-840,
and mounted as high as conveniently possible. Try
various antenna orientations, either pointing
towards the weakest station you intend to receive
or away from the major source of interference
(preferably both, although some compromise is
usually necessary in most locations). If the
antenna is intended for use with shielded coaxial
cable (which reduces losses and interference) use
the 7512 UNBAL terminals on the rear panel of the
CR-840, and connect the cable as shown.
Antennas intended for use with the 30012 BAL
terminals on the rear panel (which use feeder wire
similar to that of the internal antenna provided)
can also be used with coaxial cable if a matching
transformer is attached to the antenna. The use of
coaxial cable is advisable where the antenna must
be located some distance from the CR-840, or
where interference from automobile ignition, etc.,
is troublesome.
Attaching the coaxial cable to the accessory plug
(21
Net wire holder
(
1
)
Plug section
Inserting the core
(1) Remove the outer cover¬
ing of the coaxial cable
up to about 23 mm from
its tip, and then slip the
plug fastener over the
coaxial cable.
(2) Insert the coaxial cable
core into the hole special¬
ly prepared for the core
on the plug. Insert the
net wire holder.
(3) Finally, screw in the plug
fastener.
Fig. 1
FM BROADCAST RECEPTION
1. Set the INPUT SELECTOR to TUNER.
2. Set the TUNER push-button to FM.
3. Check that the FM indicator LEDs light at the
right-hand side of the dial.
4. All switches and knobs should be as shown in
the front-panel diagram.
5. Tune for maximum signal strength on the
SIGNAL QUALITY meter, ignoring any oscilla¬
tions of the indicating pointer position.
6. Now tune to bring the FM TUNING meter
pointer to its exact center. This is the optimum
tuning position: set it carefully.
7. Check that the FM stereo indicating LED lights
if you intend listening to a stereo rather than a
monaural broadcast.
When connecting the coaxial cable to the 75£2
UNBAL connector which is located on the rear
panel of the CR-840, first attach the cable to the
accessory plug as shown in the figure, and then
connect.
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