From The Second If To The Af Output - Kenwood TS-590SG Service Manual

RX-1
11.374M
NOTCH
from Pre Amp
(Q236)
RX-2
~60MHz
Q281,Q282
LO1 Amp1
13.174~32.195MHz
LO1
D443
IF input
(10.695M)
D441
IF input
(11.374M) Q451
2nd IF Amp1
Fig. 4 From the preamplifi er (Q236) to the second IF frequency (10.695MHz/11.374MHz)
n From the second IF to the AF output
The signal that passed through D525 then goes through
D526 and enters the FM wave detecting IC (IC591) in FM
mode, and the AM/SSB/CW/FSK wave detecting mixer
(D551, D552) in other modes.
The FM mode signal is mixed with LO3 (10.240MHz) in
the FM detecting IC (IC591), and converted into the third IF
(455kHz). The third IF signal passes through the ceramic
fi lter (CF591), demodulated into audio signals, and is then
amplifi ed by the FM AF amplifi er (IC592).
Signals of modes other than FM are mixed with LO3 (RX-
1 path: 11.398MHz, RX-2 path: 10.719MHz) in the AM/SSB/
CW/FSK wave detecting mixer (D551, D552), are converted
into the third IF (24kHz), and are then amplifi ed by the third
IF amplifi er (Q551).
CIRCUIT DESCRIPTION
Q263~Q266
1st Mixer
11.374MHz
LPF
+
Q321~Q324
1st Mixer 73.095MHz
LPF
TX
Q351,Q352
LO1 Amp2
73.125~133.095MHz
D461~D464
Blanking
XF472
D471
10.695M 15k
XF471
D474
10.695M 6k
XF473
D472
10.695M 2.7k
XF474
D472
11.374M 2.7k
XF475
D473
11.374M 500
XF301
MCF
XF371 Q391 D422,D423
1st IF Amp 2nd Mixer 10.695MHz
MCF
TX
62.4MHz
Q541
AGC AMP
D476
AGCV
D475
D477
D477
D478
Signals of FM mode and modes other than FM are sent
from the TX-RX unit (XC1-024 A/2) RIF connector (CN600)
to the Control unit (XC1-021 A/3)'s CN61.
The signal input into the Control unit (XC1-021 A/3) is
amplifi ed in the operation amplifi er (IC64, IC65), A/D con-
version is carried out by the A/D converter (IC66), and then
the DSP (IC301) fi ltering, volume control, subtone decod-
ing, etc. are carried out. The output signal from the DSP is
converted by the D/A converter (IC72), amplifi ed as an au-
dio signal in the AF power amplifi er (IC67), and is then sent
from the Control unit (XC1-021 A/3) AF connector (CN65)
to the TX-RX unit (XC1-024 A/2) CN3, and output to the
PHONES jack (J951) (fi rst priority), EXT.SP jack (J1) (second
priority), or internal speaker (third priority).
TS-590SG
11.374MHz
to 2nd IF Amp1
(Q451)
TX
Q431
LO2 Amp
LO2
Q521,Q522 D525
2nd IF Amp2 ATT
IF output
(10.695M/
11.374M)
IFGC
11