Kenwood TS-2000, Руководство по обслуживанию

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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 signal from the UHF band antenna terminal
enters the UHF section of the final unit (X45-360), passes
through the HPF and LPF and goes to the TX-RX2 unit (X57-
605). Then, it passes through the 12dB ATT circuit and goes
to the pre-amplifier (Q14). The amplified receive signal is
distributed to the paths of the main and sub-receiver sec-
tions by the L distribution circuit.
The signal distributed to the main receiver section
passes through the 3-pole variable tuning BPF and is ampli-
fied by the second amplifier (Q21). Then, it passes through
the 3-pole variable tuning BPF and is input into the mixer
(IC4) for the main band.
This 3-pole x 2 stage BPF for the UHF also controls the
tuning frequency by the output from the D/A of the TX-RX1
unit (X57-605).
The 438~450MHz signal distributed to the sub-receiver
section passes through the SAW filter (L29), is amplified by
the second amplifier (Q25), and passes through another
SAW filter (L50). The 300~438MHz and 450~512MHz sig-
nals are amplified by Q19 and goes to the mixer (IC5) for the
sub-band.
• E, E2 destinations
Then, the signal passes through the 12dB ATT circuit and
the 2-pole BPF (band-pass filter) and enters the pre-amplifier
(Q15). The amplified receive signal is distributed to the
paths of the main and sub receiver sections by the L distri-
bution circuit.
The signal distributed to the sub-receiver section passes
through a variable tuning filter and is amplified by the sec-
ond amplifier (Q22). Then, it passes through the 2-pole tun-
ing BPF, and goes to the mixer (IC5) for the sub-band com-
mon to the VHF and UHF bands. The 1-pole + 2-pole BPFs
for the sub-band VHF also control the tuning frequency by
the output from the D/A of the TX-RX1 unit (X57-605).
The signal distributed to the sub-receiver section passes
through the SAW filter (L29), is amplified in the second am-
plifier (Q25), passes through another SAW filter (L50) and
goes to the mixer (IC5) for the sub-band.
Q44
LO31
31.200MHz
Q42,43
–12dB
ATT
D10
D24 D48 D22
Q15 Q24
Q38
Q30
Q61
L23,24 L47,55
–12dB
ATT
D9
TX-RX 2 (X57-606 A/11)
D49 D23 Q14 Q21
L108~111,137 L116~119,133
XF1
41.895MHz
IC4
LO1RX
183.895~
418.105MHz
VHF
UHF
Filter
X51-315
Final
X45-360
RIF
RIF
D46
Q22
X57-605
–12dB
ATT
D10 D95
D24
D46 D22 Q15 Q22
D96
D97
D101
L28
L29
L44,52
L50
VHF
Filter
X51-315
D23
D82 Q23
D90
D91 Q25
D94 D93 Q19
–12dB
ATT
D9
TX-RX 2 (X57-606 A/11)
D92 D81 D20 Q14
UHF
Final
X45-360
IC5
Fig. 5 Main band receiver section
Fig. 6 Sub band receiver section
CIRCUIT DESCRIPTION