Kenwood Ts-2000x All Mode Multi-band Transceiver Service Manual

11
TS-2000/X
HF Receiver System and Main IF System
Three antenna terminals used for the HF and 50MHz
band reception are ANT1, ANT2 and HF RX ANT.
After the incoming signal from ANT1 and ANT2 passes
through the transmission/reception changeover relay in the
filter unit (X51-315), and is sent to the HFRX terminal of the
TX-RX unit (X57-605).  There is an HF RX ANT terminal there,
and one of the antennas can be selected from the menu for
reception .
The HF RX ANT terminal is used to connect a dedicated...

12
TS-2000/X
The signal is then amplified by the first IF amplifier (Q18)
and is converted to the second IF frequency of 10.695MHz
in the second receive mixers (Q19, 20).  The tuning fre-
quency of each stage,  the second local oscillator frequency
and others are changed according to the receive frequency
to respond to the changeover of the previously stated first IF
frequency.
A circuit for changing over the IF signal from the units of
the VHF, UHF and 1.2GHz bands and IF signal from the HF
band is...

13
TS-2000/X

Speaker output changeover
When external speakers 1 and 2 and headphones are
connected, you can change over the sub/main band outputs.
The headphone connection is preferred over the all the
speaker output and you can select from three patterns for
headphone left-right changeover.
Connection Conditions ( : connected) Output condition by connection of left table
Headphone SP1 SP2 Headphone Built-in speaker SP1 SP2
XX→Pattern 0~2 Stop X X
X→Pattern 0~2 Stop Stop X
→Pattern 0~2 Stop Stop...

14
TS-2000/X
The 118~174MHz signal distributed to the sub-receiver
unit passes through a variable tuning filter and is amplified
by the second amplifier (Q24).  Then, it passes through the
2-pole variable tuning BPF, and the 220~300 MHz signal is
amplified by Q23 and is then input into the mixer (IC5) for
the sub-band common to the VHF and UHF bands.  The 1-
pole and 2-pole BPFs for the sub-band VHF also controls the
tuning frequency by the output from the D/A of the TX-RX1
unit (X57-605).
The incoming...

15
TS-2000/X

Main receiver IF section
The signal input to IC4 is mixed with the signal produced
by amplifying the first local oscillator RXLO1 from the PLL
section by Q30 and lower hetero to the first IF of
41.895MHz.  Then, it passes through the MCF (XF1) and
AGC amplifier (Q38) and goes to the second mixer (Q42 and
43).  The signal input to the second mixer is mixed with the
signal produced by amplifying the second local oscillator
21.2MHz from the PLL section by Q44 and lower hetero to
the second IF...

16
TS-2000/X
1.2GHz Unit Receiver Section
The incoming signal from the antenna (12ANT) passes
through a filter, is amplified in the receiver RF amplifier (Q11
and 12) and input to the first mixer (Q10).
The signal is converted to the first IF (135.495MHz) in
Q10, passes through the MCF (XF1) and the AGC amplifier
(Q9) and enters the second mixer (Q7 and Q8).
The signal is converted to the second IF (10.695MHz) in
Q7 and Q8, amplified in the receiver IF amplifier (Q303) and
sent to the TX-RX1 unit...

17
TS-2000/X
 Transmit System IF  Section

 Transmission IF
The details of the processing by the DSP depend on the
mode.
• Modes other than FM
Transmission bandwidth change, speech processor and
microphone gain control are performed in the AF stage.  A
12kHz IF signal is produced after PSN modulation and out-
put modulation control.
• FM mode
The baseband processing in the AF stage is carried out by
the DSP and a VCXO (voltage controlled X’tal Oscillator) is
used as a modulator.
The transmit signal...

18
TS-2000/X
The third IF signal is input to the third transmit mixer
(Q44, 45).
A GaAs FET is used to obtain the satisfactory inter-
modulation characteristics.  VR3 adjusts the second gate
voltage to maximize the gain.  VR2 adjusts the balance of
the source current of two FETs and prevents the generation
of spurious components by minimizing IF output leakage.  It
also adjusts the leakage of the IF signal (68.985MHz) to the
minimum during 50MHz band transmission.
The signal with the target frequency...

19
TS-2000/X
R439, ALC meter
D858C
Q49
Q711
10.595MHz Q48
VOUT4
VIN4 VOUT1 VIN1
IC13
(AOUT)
HF ALC L119
VSF
43VSF
12VSF
TX-RX 1 (X57-605 A/9)D123
D119
D121X45-360
(A/2)
X45-360
(B/2)
X57-607VSR
VSR
43VSR
12VSRD124
D120
D122 X45-360
(A/2)
X45-360
(B/2)
X57-607 IC17 (Q6),
R509
50ALC
14ALC
43ALC
12ALC
7 8
3
5J7
EXT. CONT J4
REMOTE
(6 pin)
14S Q73 Q74Q76Q78
Q79
D82 D84
D105
D108
D111
D114D107 D106
1
2
11
12IC14
D113
D109
D110 Q77 Q75
Fig. 13
VHF/UHF Band Transmitter Circuit (RF~IF)
The TIF (10.595MHz) signal...

20
TS-2000/X
Transmitter Final Amplifier
The final unit (X45-360 A/2) is composed of an HF and
VHF band final amplifier, an antenna turner matching circuit,
and a power supply circuit.
The LPF section and antenna tuner detection circuit are
located in the filter unit (X51-315).
The 1.8~144MHz band is amplified by the final unit, but it
operates in the broadband up to the drive amplifier.  The
final unit amplifies signals using independent amplifiers in
the 8~50MHz and 144MHz bands.  The amplifiers are...