Acoustic research tuner service manual

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ELECTRONICS
SERVICE
MANUAL .

ITELEDYINEAOOUSTICRESEARCH

10eAmricanDrive,

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TABLE OF CONTENTS
P880

1. AMPLIFIER.. ..................... ............. 1
A. Description 0.0.0.....0...OOOOOOOOOOOOOOO...O... ..... 0...... l

1. PhonoPreamplifieroo...OOOOOOOOOOO...OOOODOOOOOOOOOI... 1
2. TonecontrOIO00.........OOQOOOOOOOO...00.0.00... ...... 1
3. BalanceCircuitOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOO 1
4. DriverAmplifier0.......0...0.0.0.0000......OOOOOOOOOOO 1
5. PowerAmplifier0.0.0.000......OOOOOOOOOOOOOOOO00...... 2
6. PowersuwlnyO....OOOOOOOOOOOOOOOOOO0.00... ..... 0...... 2
5
5
5

B. BiaSingPrmedlreoo ..... ...OOCCOOOOOOOOOOOOOOOOO ..... I ..... O

10 InitialAdjustmentIOOOOOOOOOOOOOOOOOOOOOOOOOOOO000......
2. Distortion Measurements ...... . ....................... . .

CI MmificationsandUmt$000000000OOOOOOOOOOOOOOOOOOOOOO ..... 6

1. +20 Volt Regulator
BiasingUpdate............ .....
+39VoltLeadDress
DriverBoard
Phono Preamplifier.....................................
ToneControlBoard.....................................
Turn-OnNoise.. ........ .....
RadioFrequencylnterferenee(RFI).......................
CautionsandSuggestions................................

D. specificatiomooooooooooooooooooooo ..... ...OOOOOOOOOOO. ..... 13

N
o

cwmapmhw
@QQQQQQQGQ

...a

n. mum0.00.00.00.00....OOOOOOOOOOOOOOOOOOOOIOIOOOOOO ...... 0.00.14
A. DescriptionOOOO...00......COCO-.00.... ....... 0.0.0.00000000014

. FrontEnd.................... ....... 14
. IFAmplifier............ ............ . ......... .........14
InterstationHush................... ..... ...............14
DiscriminatorandSCAFilter............................15
MultiplexSection 15
PowerSupply........................... ............ ...17

B. TunerAlignment............................................17

campaign-l

1. SweepAlignment............. .......................... 17
2. DiscriminatorZeroSetting 17
3. MonoDistortion................................... ..... 18
4. Mono Overload Distortion ......... ..... .......18
5. Sensmvxty ...... ..18
6. Multiplex Adjustments............. ........... . ...... ...18
7. PhaseAdjustment......................................l9
8. IFFilterAdjustment....................................19
9. Zero-CenterReadjustment..................... ..... ....19
10. FinalMultiplexAdjustments.............. ...... .........20
11. De-Emphasis Check ............ ........ ..20
12. PilotDropout........... ....... . ..... 20
13. DialCalibration.. ........ ........... ........21
14. FinalSensitivity Peakmg21
15. Interstation Hush and Stereo Squelch Adjustments . ......... 21
16. Final Performance Check ........... . ..... ..22