Kenwood TS-60S Service Manual page 3

r~
CIRCUIT DESCRIPTION
2. LO2 (PLL loop)
The VCO of IC10 (KCH14) generates a signal of
62.35MHz. The 10-MHz reference frequency is ap-
plied to pin 5 of IC101 (CXD1225M), and is divided by
200 (800 in FM mode) to produce a 50-kHz (1 2.5-kHz in
FM mode) comparison frequency. The output from
the VCO is applied to pin 11 of IC101, and is divided by
1247 (4988 in FM mode). It is then compared with the
50-kHz (12.5-kHz in F M mode) reference signal by the
phase comparator to lock the VCO frequency. Divide
ratio data is supplied by the digital unit.
The output is amplified by amplifier Q18 (2SC2954)
and passes through a low-pass filter. The VCO is
modulated in FM mode.
c
3. LO1 (PLL l w p l
Q1, 0 3 (2SK508NV) in the X58-4120-00 are VCOs.
0 1 generates a signal of 113.045 to 123.044MHz; and
Q3, a signal of 123.045 to 133.045MHz. K type
Q3 (2SK508NV) in the X58-4120-00 are VCO. Q3
generates a signal of 123.045 to 127.045MHz. E type
The 10-MHz reference signal is input to pin 5 of
lCl 1 (CXD1225M) and is divided by 20 to produce a
500-kHz comparison frequency. The output signal
from the VCO is mixed with a 75.045- to 75.545-MHz
signal from the PLL (described later) to produce a 38.0-
to 57.5-MHz signal. It is input to pin 11 of IC11, di-
vided, and compared with the 500-kHz signal by the
phase comparator, and the VCO frequency is locked.
Divide ratio data is supplied by the digital unit.
The 20-MHz reference signal is input to DDSl (X58-
4020-OO), and the output signal is mixed with a 4-MHz
signal by IC4 to generate a signal of 4.455 to4.955MHz
(in 5- or 200-Hz steps). The signal is mixed with the 80-
MHz signal (4 x 20-MHz reference frequency) by IC5
(SN16913P) to produce a 75.045 to 75.545MHz signal
(in 5- or 200-Hz steps).
4.
CAR
The 20-MHz reference signal is input to DDS2 (X58-
4020-OO), and the output signal is mixed by IC7 (SN
16913P) with the 10MHz signal divided by IC2 to p r o
duce a 10.695-MHz signal. This signal passes through
the band-pass filter and amplifier and is output for local
oscillation and detection.
5. DDS
The DDS is the same as that used in the TS-50.
Fig. 2 PLL circuit frequency configuration