Kenwood DP-3010 Service Manual page 16

DP-3010
28
CIRCUIT DESCRIPTION
Setting of R20 ~ R23 for Tracking Gain
Adjustment
The following simr'v explains the operations for Tracking
Gain Adjustment e- 4 the method for setting R20 ~ R23
1) Tracking Gain Asjustment Operations
@ As soon as Tracxing Gain Adjustment Operations are
started, TEL1 ans TEL2 of TC9201BF become HiZ.
@ During Tracking Sair. Acjustment the internal Tracking
Error Signal of "C9201BF is in Peak Data Hold Mode.
The Peak Data é:nieved is set to the internal resister
@ As soon as Tracxing Gain Adjustment is complete. the
Peak Data achieved in TC9201BF is decoded. TEL1 and
TEL2 are then se: tc either one of the conditions shown
in Diagram 5-1°. (Refer to TC9201BF Technical Infor-
mation for detai.s!
2) Setting Method =f R20-F23
@ The peak values of tne Tracking Error Signal within the
Pick-up dispers.on during HiZ, are set to within the
range of R20 ~~ 223 of pins TEL1 and TEL2 as shown in
Diagram 5-11
@ Each Tracking =-ror Signal within the range ts set with
R22 and R23 1c about 0.4 Vp-o (about 0.8 Vp-p) peak
value at the TSC pin.
The attentatior smtun: of the Attenuator in Diagram
5-10 1s as follows:
__ V7SO_
_ F20=R2! | R20-R21, 1 1
VEO
albedo | a SO 1
'Fox10: * Zoxt08 Rao" Aas?!
VREF
TEO
(VTEO)
(Vtso)
« Attenuator
TEL TEL2
VREF
Diagram 5-10 Tracking Gain Adjustment Construction
TSO Peak Vatue (Vp-p)
(X Veer)
TEL TEL2
0.141
<a
0.109
0.078
0
Diagram 5-11 TEL1 and TEL2 Pin Conditions
DP-3010
CIRCUIT DESCRIPTION
© Data Slicer
The Data Slicer changes the EFMI RF Signal into a Digital
Signal
By using the fact that averagely EFMO is equal to Zero DC
during H and L periods, the ELMO with the AC content ex-
cluded for the Slice Level of the Data Slicer is fedback and
used.(Diagram 5-13). When using this for the Digital PLL
Circuit of TC9201 BF, the Slice Level is fixed.
This is possible because TC9201BF has an internal Data
Correction Curcuit and thus removes problems coming
from Disc Production dispersion of a symmetry jitter (No
adjustment).
0.01 uF
V
VREF
Also, the EFMO is used for Open Collector Output. It is sug-
gested to connect a Pull-up Resister of roughly 2.2 kf. to
the Digital Supply Voltage to assist the EFMO Start Up
Characteristics.
Vopi+5V)
TC9201BF ~
Diagram 5-12 Data Sticer Construction
TC9201BF
12K SLN 4k
eae Lo SLN > *'s 7 eS. W\
a
12K 7 € wen
SLP >—VWw Zz A
+u
vm SLP
? v
40K
SLAMP
40K
VREF
Diagram 5-13 Slice Level Construction
29