Kenwood TS-2000 Service Manual page 21

Progressive wave and reflected wave output circuits
The signal is detected by L7, D3 and D4. A voltage out-
put corresponding to the progressive wave and reflected
wave is produced by synthesizing the magnetically com-
bined component by L7 with the corrected electrostatically
combined component by TC1 and C9 and detecting the re-
sulting signal.
It is adjusted by TC1 so that the reflected wave voltage
under a 50Ω load is minimized. VR1 adjusts the frequency
characteristics in the 50MHz band.
These outputs are synthesized with detected output of
the 144MHz band and are fed to the TX-RX1 unit (X57-605).
Antenna turner detection circuit
The passing current is converted to voltage by L9, and
the voltage is stepped down and detected by L10. One of
these components is buffered by Q1 and Q2 and rectified by
Q3 and Q4, are input to the phase comparator (IC2) . The IC
determines the IC2 Q output "H" or "L" according to the
phase difference with a D-flip-flop. The other component is
detected by diodes (D10 and D11) and the amplitude differ-
ence is compared with the comparator (IC1).
The capacitor capacitance on the input side is changed
according to the phase difference detection output, and the
capacitor capacitance on the output side is changed accord-
ing to the amplitude difference detection output.
UHF final unit (X45-360 B/2)
The 430MHz band transmit signal output from the TX-
RX2 unit (X57-606) is amplified to 50W by four amplifiers
(Q901, 902, 903 and 905). The final unit consists of single
amplifiers Q901, 902, 903 and 905. The input and output of
the final stage is composed of micro-strip lines. The pro-
gressive wave and reflected wave detection circuit is also
made of micro-strip lines and used for power control and
reflected wave protection.
ANT1 ANT2
AT
IC2
CK
D
Q
Q
output
IN–
IN+
IC1
CIRCUIT DESCRIPTION
HF RX ANT
ATT
–12dB
X57-605
RX
TX
L10 L9
Q3 Q1
1
L8
2
Q4 Q2
D10
1
D11
3
Filter (X51-315)
430ANT X57-606
(43RX)
DET
VSR
VSF
1.2GHz Unit Transmitter Section
The 10.595MHz transmit signal from 12TIF is amplified in
the sending IF amplifier (Q304). This signal is input into the
sending mixer (Q1 and Q2).
The 135.395MHz signal converted in Q1 and 2 passes
through the MCF (XF2) and IF amplifier (Q3), is input into the
diode mixer (D1) and converted to 1240~1300MHz. This
signal is amplified to approximately 0dB in the sending RF
amplifier (IC1 and Q5), then input to IC2.
It is amplified to approximately 1W in the drive power
module (IC2) and to approximately 10W in the final power
module (IC3), then sent to the antenna terminal (12ANT).
12ANT
D5 IC3
XF2
D1 Q3
135.395
D10
MHz
1104~
1165MHz
14MHz : E, 10&14MHz : K
L6
D4 D3
L7
Fig. 16
TS-2000/X
X57-606
Q905 Q903 Q902 Q901
D6
Final (X45-360 B/2)
Fig. 17
L12 L10
IC2 Q5 IC1
1240~ 1240~
1300MHz 1300MHz
X57-605
Q1,2 Q304
12TIF
10.695
MHz
Q48
D8
Q15
124.800
TX-RX 3 (X57-607)
MHz
Fig. 18
LPF
1.8MHz
3.5MHz
7MHz
10MHz : E
X45-360
(A/2)
21MHz Q6,7
28MHz
X57-605
50MHz
VSR
VSF
21