Advent 300

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A DV E\ I Service Manual for Model 300
Beginning with Serial Numbers J0 07000 and Y0 01000

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Table of Contents

I. GENERAL INFORMATION IV. POWER SUPPLY 120 VAC/12 VDC
l 1 Specifications , . 3 4.1 300/I2 VDC Board View . . . . . 10
1.2 Required Test Equipment . 2 42 300/12 VDC Schematic Diagram. . . 10
4.3 120 VAC and Amplifier
Schematic Diagram . . . . l
' AMPLIFIER SECTION 4.4 Tuner Schematic Diagram . . . . . ll
2.] Preparation . . . . . . 3
2.2 Power Supply and Output Bias . . . . 3 V. PARTS LIST
2.3 Amplifier Test . . . . . . . . 3-4
2.4 Phono Pre-Amp . . . . . . . . 4-5 51 AmplifichC Board . . . . . . l3
2.5 Amplifier Board View . , . . . , . 5 5-2 Heat Sink Mounting Hardware . . l3 l4
5-3 Power Supply 110 VAC . . . . . 14
5-4 Tuner Board . . . . . . 14-15
I . R ECTION
II TUNE S 5~5 Power Supply 12 VDC. . . . . . 15
3.1 Preparation. _ 6 5-6 Cosmetic Parts . . . . . . . . l5
3.2 Detector Alignment . . . . . . b
3.3 IF Alignment . , . . . . . 6-7
3.4 Local Oscillator ( alihratinn 7
3.5 RF Alignment 7
3.6 Stereo Alignment 7
3.7 Tuner Board View . . 8
3.8 Multiplex Filler Adjustment . 9
3.9 Transistor Basing Diagrams 9

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GENERAL INFORMATION

1.1 SPECIFICATIONS

Amplifier section

Continuous power output, both channels driven, 8 ohms
40 Hz to 20 kHz: 15 watts + 15 watts
1 kHz: 18 watts + 18 watts

Total harmonic distortion, 40 Hz to 20 kHz
15 watts.per channel: less than 0.5%
7.5 watts per channel: less than 0.1%

Intermodulation distortion
60/7000 Hz; 4: I: less than 0.15%

Preamp section
Maximum output: greater than 6V

Hum and noise, shorted input, A-welghted
Phone ref 10 mV @ 1 kHz: better than 80 dB
Aux, Tape monitor: better than 80 dB

Total Harmonic distortion
20 Hz to 20 kHz: less than 0.1% (2.5V)

lntermodulation distortion
60/7000 Hz; 4: 1: less than 0.1%(2.5V)

Tone controls

Bass: ilOdB @100 Hz
Treble: £10 dB @ 10,000 Hz

Infrasonic filter
Phono: 0 dB @ 25 Hz
-1 dB @ 20 Hz
-31 dB @ 4 Hz

FM tuner section

Mono sensitivity
ll-lF 30 dB: 2.5 uV'
IHF 50 dB: 3.5 uV

Stereo sensitivity
IHF 50 dB: 35 uV

Total harmonic distortion, 400 Hz, 1le
Mono: less than 0.15%
Stereo: less than 0.2%
Stereo separation, l]~lF
400 Hz: greater than 40 dB
30 Hz to 10 kHz: 28 (18
Alternate channel selectivity: 70 dB

Image rejection: 55 dB

IF rejection: 70 dB
Spurious rejection: 70 dB
AM suppression: 60 dB
Capture ratio: 1.6 dB
Antenna input: 300 ohms balanced
Power requirements
Model 300: 120 VAC, 60 Hz,
100 watts maximum

Model 300/12: 12 VDC, negative
ground, 7 amps maximum

1.2

REQUIRED TEST EQUIPMENT

The following list of test equipment is required to properly service the Model 300 stereo receiver.

1. Audio Oscillator, Hewlett Packard 204C or equivalent.
. Precision ACVM, Hewlett Packard 400 CL or equivalent.
. Oscilloscope, Tektronix T922 or equivalent.

Osmth

Sound Technology Model 1000A or equivalent.

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8. AC line varlac. General Radio W5MT3A or equivalent.

. Volt, Ohm Meter, Hewlett Packard Model 427A or equivalent.
. DistortioWHhr/lett Packard Model 333A or equivalent.
. FM Multiplex Generator, less than 0.2 TI-[D and better than -60 dB signal to noise.

. Two (2), Eight ohm load resistors, 1%, 25 watt minimum rating.

9. Frequency counter, 100 MHz, Data Precision Model 5740 or equivalent.