Sanyo JCX 2300K Service Manual

Page 2

FM IF ADJUSTMENT

1. V curve adjustment

1) Connect TP3 (Hot) and TPG (Eartch) to the output
terminal of the sweep generator, and TP4 (H) and TP9
(E) to the input terminal.

2) Connect a resistance load of about 10 to 50 K-ohms to
the input of the sweep' generator and disconnect the
tuning meter lead wires from the circuit board.

3) Cut off ceramic filter 621 3 (0.022uF) at one end.

4) Make adjustment while keeping the output from the
sweep generator at the low level (where noise appears
on the Waveform).

5) While watching the sweep waveform at T201, adjust the
ceramic filter until the sweep waveform presents the
pattern as in Fig.1.

* TPG is a shield plate.

FMIF Curve

ZERO-POINT ADJUSTMENT OF CENTER METER
Set FM SG as follows: modulation frequency 1kHz, frequency
deviation 75kHz DIV. (100% modulation).
Connect a balanced dummy of 300 ohms between FM 36 and
the unit (at the 300-ohm terminal of the external antenna).
Then, connect the center meter to the unit at the center
meter output terminal.
1) Set the tuning_dial of the unit to 98MHz (where no
broadcasting signal is coming in).
2) While keeping the FM SG output level to 0 (less than-
10dB), adjust the primary core (on the pattern side) of
T202 until the center meter needle stands at the zero

2. 5 curve adjustment

1) Connect TP3 (H) and TP6 (E) to the output the sweep
generator. Connect TP9 (E) and TP10 (H) to its input.
NOTE: It is necessary to connect to the input of the

sweep generator a capacitor (lit/16V) for
cutting DC current.

2) Adjust the primary core (on the pattern side) of dual
tuning coil T202 until the 8 curve presents the pattern
as in Fig. 2. Avoid turning the secondary core (on the
parts side) unless absolutely necessary.

FM Detector Curve

3) Adjust the frequency output of FM 86 so that the
center meter needle stands at the zero point.

4) Reduce the distortion factor to a minimum by turning
the secondary core (on the parts side) of T202. Make
this adjustment at the FM SG output level of 40 60dB.

5) Repeat steps 2) and 3) above.

6) Set the FM SG output level to 60dB. Turn T201 until
the distortion factor becomes minimal.

* T201 should be adjusted only slightly. If it has been
turned more than necessary, go through the above
steps from 1 ).

point. 7) Repeat steps 2) and 3).
USCSCCVE
VTVM
I I
SET
x. o a
u _ [HF FILTER .
! .-. I © 1
goooo©oaooo 15:}
TUNING METER DISTDRTIUN
E
E... 0 © 0
SDI-=9 u:- 3
FM TRACKING

Set FM SG as follows: modulation frequency 1kHz,frequency

deviation 75kHz DIV. (100% modulation).

Flip the MODE switch of the unit to "MONO". Connect FM

SG and a dummy load as instructed in 3. Zero-point

adjustment of center meter.

Such testers as VTVM should be connected to the unit at the

TAPE REC output terminal (RCA pin).

* The total load impedance of the testers connected to the
unit at the REC output terminal should be 100 K-ohms.

1) Make LOW TRACKING adjustment by means of L102 and
L101. Use BOMHz FM signal for this purpose.

2) Make HIGH TRACKING adjustment by means of CT2 and
CT1. Use 106MHz FM signal for this purpose.

3) Make complete TRACKING adjustment by repeating steps
(1) and (2).

* When properly adjusted, the distortion factor of the output
from the unit is reduced to a minimUm, provided that the
distortion factor of the 36 output is anout 3%.