Kenwood TS-60S Service Manual page 8

CIRCUIT DESCRIPTION
3. SSB, AM, CW filter circuit
The second IF signal amplified by 0 2 1 is input to the
X48-3110-00 unit in all modes except FM.
If an optional CW filter (XF1) is installed and CW
NARROW is elected in CW mode, the signal passes
through XF1 according to the control signal from the
microcomauter. If XF1 is not installed or CW NAR-
XF2.
In A M mode, the signal passes through XF3 and XF2
,-
-
-.-
- ~~-
ROW is nbt selected, the signal passes through XF3
insertion loss
as in SSB mode if AM NARROW is selected. If AM
NARROW is not selected, the signal passes through
XF2 only.
In FM mode, the signal does not pass through the
filter circuit in this unit.
Item
Nominal center frequency
Center frequency deviation
Pass bandwdth and
Attenuation bandwidth
Rinnle
and XF2.
In SSB mode, the signal passes through XF3 and
-
~
CW
(OPTION)
m
Rating
'
10.695MHz
-
Within i20OHz at 6dB
22kHz or more at 6dB
i-l5kHz or less at 20dB
+2.4kHz or less at 6 0 d ~
? r i ~ w
Guaranteed attenuation
/
60dB or more with~n fo
i
4OkHz
Terminating impedance 1 2 k R i 5 % 1 6 p F i 5 %
lNO--FOOu
Bandwidth
XF1 : 500Hz
XF2 : 6kHz
XF3 : 24kHz
Table 4 MCF (L71-0249-05) : IF unit XF3
Fig. 7 Filter circuit
4. SSB, AM, CW detection circuit
After unwanted signal components have been re-
-
moved in the X4E3110-00 unit, the signal is input to
IC3 IKCD08). The signal amplified by IC3 is mixed with
the CAR signal input from C N l l in SSB and CW
modes, and detected to output an audio signal. In AM
mode, the signal is envelope-detected by the diode
and capacitor to output an audio signal.
Item
5. FM detection circuit
The impedance of the second IF signal amplified by
0 2 1 is converted by 0 2 3 (RU201) in FM mode, and
unwanted signal components are removed by the CF
(XF2). The resulting signal is input to the detection IC
(IC2: KCD04). The signal is then mixed with the 10.24-
MHz oscillator signal to generate the 455-kHz signal.
The signal is passed through ceramic filter CFI, and
detected by the quadrature detector with the signal
phase-shifted by CD1
Rating
Nominal center frequency
1
10,695kHz
deviation
1
Within +80Hz at 6dB
.-.,..,..-....s . , . . v
,
.-"".-"?.
I
pears at the base of 031. When the S Q ~ V R is turned
Table 2 MCF (L71-0283-05)
:
IF unit XF1 (Option)
clockwise. the emitter voltaae of 0 3 1 increases and
6. Squelch circuit
7
~ ~ ~ ~ ~ ~~
~~-
Insertion loss
1
Within 5dB i 2dB
~ ~ ~ ~ i ~ ~ t i ~ ~
irnn~iianrr
1
19nnoifin~
p
In all modes except FM, the 10.695-MHz IF signal is
detected by a diode in IC3, passed through 0 2 9 and
030, and a voltage proportional to the signal level ap-
-
Q32 is switched on.
In FM mode, as the IF signal increases, the noise
level decreases, and the voltage at the SQ pin de-
creases, making the SC pin low. When the SO VR is
turned clockwise, the voltage at the SQ pin rises, and
the SC pin goes high. Current flows through R77, and
0 3 2 turns on.
0 3 5 turns on to mute the AF signal line. (Fig. 8)
Item Rating
Table 3 MCF lL71-0433-05) : IF unit XF2
-
Nominal center frequency
Pass bandwidth
Atten~~atlon bandwidth
Ripple
Insenion loss
Guaranteed attenuation
Terminating impedance
'
10695MHz
GkHz or more
at
GdB
4OkHz
or
less at 60dB
2dB or less
3dB or less
60dB or more within fo f 1 MHz
1 2 k n
+
10% I ~ ~ F
+
10%