Operation Manual

FROM
RIGHT
CHANNEL
DUBBING
OUT
TAPE OUT
TAPE IN
AUX
AM AUDIO
FM AUOIO
PHONO
TECHNICAL
DESCRIPTION
GENERAL
Figure 9 is a block diagram of the Model 2230
Receiver showing the main functional elements and
input and output signal routing. Each AM and FM
front end has its own IF stages. For clarity, only
the left audio channel is shown; the right audio
channel is identical. The MONO switch is common
to both channels. All audio controls are ganged,to
their counterparts in the right channel. The left
channel half of the front panel dubbing IN and
dubbing OUT jacks are shown interconnected
in this diagram. The right channel ot each jack
is wired to the same circuit point in the right
channel.
11
QUAD
RADIAL
FM SIGNAL STRENGTH METER
TO SELECTOR SWITCH
STEREO
INOICATOR
TO MUTING
SWITCH
TO
SElECTOR
SWITCH
SPEAKER
SYSTEMS
Figure9. FunctionalBlockDiagram
FUNCTIONAL
DESCRIPTION
FRONT END
FM antenna signals are applied through a balun
transformer and the antenna ATTENUATOR
switch to the antenna coil which drives a field-
effect transistor RF amplifier. When the AT-
TENUATOR pushswitch is placed in the "out"
position the attenuator circuit is cut off the FM
signals are directly fed to the FM antenna coil.
With ATTENUATOR pushswitch placed in the
"IN" position, the signals are attenuated about
20dB by the attenuator circuit, then fed to the
antenna coil. The signals from the RF ampl ifier are
fed through the double-tuned RF tank circuit to
the FET Mixer stage,wh ich is also fed by the signal