Hitachi DPK 340 Service Manual

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HITACHI

Hitachi. Ltd. Tokyo Japan

HITACHI SOLID STATE
STIIIEOII'IOIIIC RADIO PIIOIIOGIIAPII

MODEL DPK-340

SERVICE MANUAL

D P K - 3 4 O
N O. 4 4 1 9 7 2
1. SPECIFICATIONS
FM SECTION PLAYER ........................ BSR 0-141
Frequency range ................ 88 - 108MHz _ ,,
Usable sensitivity (IHF) . .. 3-0l1V SPEAKER ....................... 3342 Woofer
Image rejection . . 50dB weeter
IF rejection . 70dB ACCESSORIES
Distortion ...................... MONO 0.5% AFC, Muting, Mode, Stereo indicator, Tuning meter, Head-
STEREO 1.2% phone jack, Stereo & Matrix
Signal to noise radio .............. SOdB
Stereo separation ................ 30:13 (1kHZ) E|o|i3|vEE|$S|%(|)\II:SUMP1-ION """"" AC 120V BOHZ 63W
AM SECT'ON Center box .. .. 1873/16(W) x 10.1mm) x 1523/6403) in.
Frequency range ................. 530 7 1605kHz (461 x 255 x 390 mm)
sable :"S'VV'W ('F 20 Speaker box .. .11-3/16iW)x 18-7/64IH) x 7»3/32(D) in.
lmage rejection ........ .. 35dB (284 x 460 x 180 mm)
IF rejection .................... 40dB WEIGHT
AUDIO SECTION ............... . ......... 27.5 lbs. (12.5 kg)
Frequency response .............. 20 - ZOOOOHZ
Total peak power . . 50W
Music power (SQ) . . 20W/ch
RMS power (5% THD) (SQ) ....... 13W/ch

2. FEATURES

1. The FM tuner uses a high-performance FET (field-effect transistor) at its front end for minimizing noise and
eliminating interference.
2. The FM tuner incorporates a mechanical filter of sharp characteristic in its IF amplifier for improved
selectivity and distortion characteristics.
3. The FM stereo multiplex circuit switches automatically for stereo and monaural receptions, so that FM
stereo programs can always be received stably.
. The tuning meter indicates the correct and accurate tuning point,
. The FM muting circuit enables the optimum reception without interstation noise at both high and low
radio field strengths simply by operating the function switch.
6. The complementary ITL-OTL circuit coupled with high-performance HITACHI silicon transistors minimizes
the distortion.

III-b

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MODEL DPK-34O SERVICE MANUAL

3. SERVICE POINT
INSTRUCTION FOR REMOVING CHANGER AND CHASSIS

1.

Remove the nylon washers from the lock screws of
the changer.

. Push down the changer firmly and drive in the

screw completely.

. Lift the changer up and remove 2 lock brackets

(near the changer lock screw located underneath
changer board of the cabinet)

Remove 5 chassis screws at the bottom of the
cabinet.

. Then pull the chassis out from the front of the

cabinet.

4. ALIGNMENT INSTRUCTIONS

4-1 AM IF & RF ALIGNMENT

Do not attempt alignment unless the following equipment is available.

Equipment Description

AM Signal Generator, Oscilloscope, AC VTVM

chassis

changer

Set function selector switch to AM cabinet
Output of signal generator should be no higher than necessary to obtain an out reading. Fig. 1
SIGNAL GENERATOR TUNING DIAL OUTPUT
STEP SETTING CONNECTED TO ADJUSTMENT REMARKS
CONNECTED TO FREQUENCY
1 Connect the loop 455 kHz Quieting point Tape recorder T103, T203 Adjust for
antenna to AM on band OUT terminal & T205 maximum output
Signal Generator AC VTVM Set VRZOl center
2 Connect the loop 600 kHz 600 kHz Tape recorder L103 Adjust for
antenna to AM Input 74dB OUT terminal maximum output
Signal Generator 400 Hz AC VTVM
30% mod.
3 Connect the loop 1400 kHz 1400 kHz Tape recorder TC4 Adjust for
antenna to AM Input 74dB OUT terminal maximum output
Signal Generator 400 Hz AC VTVM
30% mod.
4 Repeat step 2 & 3 until no further improvement is possible.
5 Connect the loop 600 kHz 600 kHz Tape recorder L1 Adjust for
antenna to AM Weak input OUT terminal maximum output
Signal Generator 400 Hz AC VTVM
30% mod.
6 Connect the loop 1400 kHz 1400 kHz Tape recorder TC3 Adjust for
antenna to AM Weak input OUT terminal maximum output
Signal Generator 400 Hz AC VTVM
30% mod.
7 Repeat step 5 & 6 until no further improvement is possible.
8 Connect the loop 1000 kHz 1000 kHz Tape recorder VR201 Adjust for
antenna to AM Input 74dB OUT" terminal 250mV iZdB
Signal Generator 4001-11 AC VTVM
30% mod