Hitachi HRD-MD05 Serviceanleitung Seite 6

HRD-MD05
FM Section
FUNCTION: Tuner (FM) VOLUME: MIN FM MODE:
Signal Generator
Sweep Generator
Dist.
Frequency Counter
(Note 1)
Connection
Input
Sequence Output Tuning
IN
1 IF Amp.
o-W-I
100K 0.1
out
IN
2 "S" curve
0.1
100K 0.1g
0.1 g 100K
ANT. Terminal
(75 ohms)
3 Discriminator
98.00MHz
400 Hz, 60 dB,
22.5 kHz (dev.)
Covering
4
Portée
Tracking
5
Alignement
100K
ANT. Terminal
19kHz
6
75 ohms 60dBg
98.00MHz
Free Running
Non modulated
Note I: Performadjustmentat least 3 minutes after the power has beenswitchedon.
Note 2:
Usinga sweepgenerator, a pply low-inputsignals(with a smallamountOfnoise superimposed asin fig. A), andadjust
the FM IFTso that the waveforms are brought to their maximum in center markerfrequency(10.7 MHz).
Note 3: Adjust the 1—202 a nd obtain the S-curve.
Note 4: Connecta DC null meter and adjust L202for a reading of OV± 30mV.
FMTunerpackis alignedbeforeshipping, s o it is not necessary to adjustcoveringandtracking.
Note 5:
— 10 —
MONO
Oscilloscope
DC Null Meter
Distortion Meter
Setting Adjust for
Signal Adjust Indication
FM IFT
10.7MHz (Note 2)
(Tuner Pack)
Straight line
10.7MHz L202
(Note 3)
98.00MHz 1202 (Note 4)
(Note 5)
(Note 5)
98.00MHz RT301 19kHz ± 50Hz
AM Section
Condition: Function: TUNER (AM)
Conditions:
Modulation: 400Hz
Connection
input
Sequence Tuning
€3
e-.IHN+OTP. 8 0-vw.l}-€
1 IF Amp.
0.1B 100K 100K 0.1
TP. 7
530kHz
(for US, CS)or
2 MW Covering
4
522kHz
¯ (exceptUS,CS)
GND
600kHz
Loop antenna
3 MW Tracking
or
603kHz
ooe
AM IF our
10
4 LW Covering
153kHz
GND
5 LW Tracking
164kHz
AM IF OUT
Caution
I. AdjustT201so thatthewaveformis asshownin Fig.B.After adjustingasabove,increase the outputlevelof thesweep
generatorand adjust T201 again so that the top of the waveform A (indicatedin Fig. C) will be flat and wide.
2. Carry out this adjustment for final adjustment of the coil only when you have moved the core by mistake.
3. Settheinputlevelto 74dB/min coarseadjustment. R educe the input level t o minimum (60dB/m)asadjustmentproceeds.
Fig.A
Fig. B
HRD-MD05
Function: TUNER
Modulation: 400Hz 30%
Setting Adjust for
Signal Indication
450kHz
Caution I
530kHz: 1.25VDC
L153 522kHz: 1.2VDC
Caution 2
600kHz
Output max.
1151
or
Caution 3
603kHz
1.2V
L154
Caution 2
Output max.
164kHz L152
Caution 3
Fig. C