Buick LeSabre 1965 Service Manual page 735

11 - 2 RADIO AND ANTENNA
ACCESSORIES
,ON-OFF
IVOLUME
SPEAKER BALANCE
CONTROL (CARS EQUIPPED
[WITH REAR SPEAKERS ONLY)]
TONE
'CONTROL
STATION
SENSITIVITY CONTROL
^ SELECTOR BAR
TUNING
SPEAKER BALANCE
CONTROL (CARS EQUIPPED
WITH REAR SPEAKERS
ONLY)
ON-OFF
VOLUME
CONTROL
TONE
CONTROL
PUSH BUTTONS MANUAL
TUNING
Figure 11-2—Sonomatic and Wonderbar Radio Receivers - 4 9 0 0 0 Series
control knob permits manual se-
lection of other stations.
The Wonderbar radio receiver
also contains an automatic signal-
seeking tuner by which the oper-
ator can change stations by
merely depressing the selector
bar on the receiver. The signal
seeking tuner (Wonderbar radio
only) sweeps the broadcast band
from low to high frequency until
a signal of sufficient strength is
found. The tuning mechanism is
driven by a spring loaded me-
chanical motor which is stopped
on station by a triggering circuit
actuated by v o l t a g e developed
from the incoming signal. The
number of stations on which the
tuner will stop can be regulated
by use of sensitivity control on
the receiver.
Both radios use a s e c t i o n a l
manual or e l e c t r i c antenna
mounted on the right front fender.
The manual antenna, which may
be extended and retracted by
hand, is standard equipment. The
electrically operated antenna is
available as optional equipment.
In the electric antenna, a motor
drives a nylon reed attached to
the upper section of the antenna.
A 3-position switch on the acces-
sory panel above the radio con-
trols the antenna motor, which
will run in either direction. Push-
ing the switch to the front lowers
the antenna, and pulling to the
rear raises the antenna. When the
switch is released, it returns to
center off position.
CAUTION: N e v e r attempt to
force an electric antenna up or
down by hand. This will cause
permanent damage to the oper-
ating mechanism.
Radio noise interference is re-
duced by use of noise suppressor
capacitors (see Figure 11-3) and
also the inherent resistance of
the wiring. The built-in resist-
ance of each spark plug wire ap-
proximates 4,000 ohms per foot.
The ignition coil noise suppressor
capacitor (0.3 MF) is mounted on
the coil bracket and the lead is
connected to the positive battery
(+) terminal of ignition coil. If
this polarity is not observed, ex-
cessive pitting of distributor con-
tact points will result. The
voltage regulator and delcotron
noise suppressors are both rated
at 0.5 MF and each is mounted
on the exterior of their respective
units.
A static collector is installed in
each front wheel hub cup. For
good results the cup and the
center of steering knuckle spindle
must be clean and free from
grease. The center of static col-
lector is made of self-lubricating
material. In addition to the items
mentioned above, bond or ground
straps are connected between the
cowl and the rear corners of the
engine.
b. Switch, Volume, and
Tone Control Operation
Clockwise rotation of the switch
knob to the left of dial, turns the
radio on, and further rotation in-
creases the volume.
High fidelity (true tone) is pro-
vided when the tone control knob,
behind the switch knob, is at the
mid-position of the tone control
range. A detent in the circuit
provides a method of quick loca-
tion of this position. Rotation
clockwise of the tone control knob
will diminish bass tones. Rota-
tion counterclockwise w i l l di-
minish treble tones.
The rear speaker for the 45000,
46000, 48000 and 49000 Series
may be optionally installed at the
factory or by the dealer. When
the rear speaker is installed, the
inner knob located behind the
radio manual tuning knob, serves
as the speaker balance control
(see Figures 11-1 and 11-2).
The clockwise rotation of the con-
trol turns on the rear speaker
only, the midway position blends