McIntosh MR 85 Service Manual

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McIntosh MR 85 Service Manual

Extracted text from McIntosh MR 85 Service Manual (Ocr-read)

Page 1

PERFORMANCE SPECIFICATIONS 2 NOTES 1. The heavy notes on the schematic denote the primarysignal path. 2. Unless otherwise noted, all voltages indicated on the schematics are measured under the following conditions: a. AC input at 120 volts, 50/60Hz. b. All voltages are +/-10% with respect to ground. A high impedance (10 megaohm) voltmeter must be used. 3. Unless otherwise specified: a. Resistor values are in ohms. b. Capacitor values are microfarads (uF). c. Inductor values are in microhenries (uH). 4. On PC board drawings, Square pad indicates: a. Polarized Capacitors - Positive b. Diodes - Cathode c. Others - Pin 1 5. WARNING Parts marked with the symbol have critical characteristics. Use only replacement parts recom- mended by the manufacturer. FM Tuner Specifications Useable Sensitivity 14dBF which is 1.4uV across 75 ohms 50dB Quieting Sensitivity Mono: 19dBF which is 2.4uV across 75 ohms Stereo: 35dBF which is 15uV across 75 ohms Signal To Noise Ratio Mono: 75dB Stereo: 70dB Frequency Response Mono: + 0, - 1dB from 20 to 15,000Hz Stereo: + 0, - 1dB from 20 to 15,000Hz Harmonic Distortion Mono: 0.3% at 100Hz 0.3% at 1,000Hz 0.3% at 10,000Hz Stereo: 0.45% at 100Hz 0.45% at 1,000Hz 0.65% at 10,000Hz Intermodulation Distortion Mono 0.25% Stereo 0.45% Capture Ratio 1.2dB Alternate Channel Selectivity 75dB Spurious Response 100dB Image Response 75dB RF Intermodulation 65dB Stereo Separation 45dB at 100Hz 45dB at 1,000Hz 35dB at 10,000Hz SCA Rejection 65dB AM Tuner Specifications Sensitivity20uV External Antenna Input Signal To Noise Ratio 48dB at 30% modulation 58dB at 100% modulation Harmonic Distortion 0.5% maximum at 50% modulation Frequency Response 50Hz to 6kHz NRSC Adjacent Channel Selectivity 45dB minimum IHF Image Rejection 65dB minimum from 540 to 1600kHz IF Rejection 80dB minimum General Specifications Rated Output Fixed output: 1.2 Volts Variable output: 0 - 1.2 Volts Output Impedance Less than 100 ohms Power Requirements 100 Volts, 50/60Hz at 20 watts 110 Volts, 50/60Hz at 20 watts 120 Volts, 50/60Hz at 20 watts 220 Volts, 50/60Hz at 20 watts 230 Volts, 50/60Hz at 20 watts 240 Volts, 50/60Hz at 20 watts Note Refer to the rear panel of the MR85 for the correct voltage. Dimensions17-1/2 (44.5cm) W, 5-3/8 (13.7cm) H, 17-1/2 (44.5cm) D, (including clearance for connectors) Weight 25.5 pounds (11.6 kg) net, 43 pounds (19.5 kg) in shipping carton

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REAR PANEL MR85 SECTION LOCATION 3 TOP VIEW WITH COVER REMOVED

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78 2 POWER SUPPLY 049410

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1920 4A TUNER 049084 4B 5A RAA1 049084 5B

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EXPLODED VIEW PARTS LIST 24 1 016419 FRONT GLASS 2 171320C/A SWITCH 3 017531PUSHBUTTON ASSY RED 4 017517PUSHBUTTON ASSY 5 078033O-RING 6 049411KNOB ASSY 7 104073 BLK FELT WASHER 8 0186115 ENDCAP 9 101042 TS 4-40 X 1/2 SLOT FILLISTER 10 094360 FOAM TAPE 1/2 X1/2 11 004810EXTRUSION BRACKET 5 12 018609 BOTTOM EXTRUSION 13 101172 TCS 6-32 X 1/4 PHIL FLAT U/C 14 100147 MS 6-32 X 3/16 PHIL FLAT U/C 15 018587 TOP EXTRUSION 16 022314LED SHIELD 17 017806PLEXIGLAS LOWER 18 017805PLEXIGLAS UPPER 19 017738 FRONT PANEL FILTER 21 017737 VINYL LOCATOR 22 049409DISPLAY PCB ASSY 23 100275 MS 6-32 X 1/2 PHIL BLK TRUSS HD 24 078031GROMMET 25 021030 SPACER: 6 X 1/4 26 110004 M7 X .75 HEX CONTROL NUT 27 104013 LK WASH: 5/16 X .435 X .002 INT STAR 28 049106 SWITCH PCB ASSY 29 021063 STANDOFF: 6-32 X 1-1/8 HEX 30 005077SUBPANEL 31 104007 LK WASH: 6 X .288 INT STAR 32 100157 MS 6-32 X 1/4 PHIL PAN ZINC 33 005072TRANSFORMER CAN 34 101054 TS 6-32 X 1/4 PHIL PAN TAPTITE BLK 35 102045 KEP-NUT 6-32 SPECIAL 36 078017 GROMMET 3/4 X 9/16 37 074091 AC TERMINAL BLOCK 38 104001 FLAT STEEL WASH #4 X 9/32 X .025 39 104004 LK WASH: 5 X .255 INT STAR 40 102022 MN 4-40 3/16 X 1/16 41 005073 CHASSIS TRAY 42 178160 FUSE HOLDER 43 100284 SEMS 2-56 X 1/4 PHIL PAN 44 004943 RIGHT SIDE PANEL 45 004942 LEFT SIDE PANEL 46 004940 TOP COVER 47 101078 TS 8-32 X 5/16 PHIL PAN BLK 48 004860 BOTTOM COVER 49 017218PLASTIC FEET-BLACK 50 104080 FLAT WASHER #10 CLEAR ZINC 51 100159 MS 10-32 X 3/4 PH PAN BLK ZINC 52 049410 POWER PCB ASSY 53 049084TUNER ASSY/RAA1 54 004903TUNER COVER 55 101097 TS 6-32 X 3/16 PHIL PAN TAP 56 005070 REAR PANEL 57 117711 AC RECEPT WITH LINE FILTER 58 102001 KEP NUT 4-40 CADMIUM PLATE 59 102020 MACH NUT: 6-32 SELF-LOCK 60 005078 REAR PANEL PLUG 61 100250 SEMS MS 6-32 X 1/4 PHIL PAN 62 101114 SM 4-24 X 1/2 PHIL PAN TYPE A 63 101109 TS 6-32 X 5 /16 PHIL PAN TAPTITE Ref. No.Part No.Description