McIntosh-MAC1500-rec-sm维修电路原理图.pdf

MAC 1500 STEREO RECEIVER WARRANTY STATION SERVICE MANUAL CONTENTS McINTOSH AUDIO COMPANY 2 Chambers St., Binghamton, N.Y. 13903 MAC 1500 INTRODUCTION 1 FM ALIGNMENT CHART 2-3 MULTIPLEX DECODER ALIGNMENT CHART _ 4-5 SCHEMATIC 6-7 TESTS AND ADJUSTMENTS 8 DIAL STRINGING 8 PARTS LIST 9-14 TOP AND BOTTOM VIEWS 15 SPECIFICATIONS 16 BLOCK DIAGRAM 16 RadioFans.CN 收音机爱 好者资料库 MAC 1500 STEREO RECEIVER I N T R O D U C T I O N All Mclntosh tuners are carefully aligned and tested at the factory using the finest available test equipment. All Mclntosh tuners will meet their published specifica- tions when shipped from the factory. After extensive operation, especially when tubes have been replaced, it may be desirable to realign the timer circuits for best performance. This manual gives complete information on the circuit realignment procedure for the MAC 1500 receiver. The test equipment listed below (or its equivalent) is necessary to properly align a MAC 1500. The accuracy of the alignment will be directly related to the accuracy and calibration of the test equipment used. FM Signal Generator (Measurements 210A or equivalent) VTVM Multiplex Generator (RCA WR51A or equivalent) 10.7 MC Generator (Preferably crystal controlled) Oscilloscope (Hewlett -Packard 120B or equivalent) Harmonic Distortion Analyzer (Hewlett-Packard 330B or equivalent) If the necessary test equipment is not available, alignment should not be attempted. You may contact the Mclntosh Customer Service Department for additional information. Customer Service Mclntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York Our telephone number is 723-5491 The direct dial area code is 607 1 RadioFans.CN 收音机爱 好者资料库 MAC 1500 STEPS 1 2 3 4 5 6 7 8 9 10 11 2 TUNER DIAL SETTING Point of no interference and no signal SAME SAME 105MC 90MC 105MC 90MC 90MC 105MC and 90MC 90MC 90MC SIGNAL GENERATOR FREQ. 10.7MC SAME SAME 105MC 90MC 105MC 90MC 90MC 105MC and 90MC 90MC 90MC COUPLING Through external .01 MFD capacitor to mixer grid (pin 4 or 6DS4, V2) SAME SAME 300 ohm antenna terminals with matching network* SAME SAME SAME SAME SAME SAME SAME MODULATION cw SAME SAME 400 cycles 75KC deviation (100% modulation) SAME SAME SAME SAME 50 cps 150KC deviation Approx. 5 microvolts at antenna terminals 400 cycles 75KC deviation (100% modulation) SAME INDICATOR TYPE VTVM SAME SAME CONNECTED TO TP#1 Pin 1 of T4 TP#2 VTVM connected to TP#2 and. scope connected to L or R tape output SAME SAME SAME VTVM connected to TP#2; scope and distortion analyzer connected to L or R tape output See note * at bottom of page Scope connected to L or R tape output VTVM connected to TP#1; scope and distortion analyzer connected to L or R tape output RadioFans.CN 收音机爱 好者资料库 FM ALIGNMENT ADJUST Top (secondary) and bottom (primary) of T1.T2, T3 Primary and secondary of T4 Secondary (top) of T-5 -4 L-4 C-2, C-3 L-1, L-2, L3 Primary (bottom) of T-5 L-2, C-3 Muting threshold control TEST LIMITS Maximum pos- sible negative voltage Maximum pos- sible negative voltage (should be 20 to 30 volts) Adjust for 0 volts Maximum nega- tive voltage SAME SAME SAME 0.5% distortion or less Minimum tilt IHFM Sensitivity 2.5 microvolts for 3% total noise and distortion REMARKS Before making any adjustments, set the controls as follows: a) Input selector switch to FM mono, b) Volume control maximum CCW. c) Muting pot maximum CW. d) Muting OUT. e) Stereo light adjust maximum CW. Shunt to ground the winding not being adjusted. Do this with a .01 MFD capacitor in series with a 1K resistor. Attenuate signal generator until output voltage at TP#1 is less than 1.5 volts with one IF trans- former winding shunted. IF transformers have terminal #1 marked with a green dot and are numbered clockwise. _ Muting pot. MUST be maximum CW. The primary (bottom) of T-5 should be adjusted only if a distortion analyzer is available. Repeat steps 4 and 5 until dial calibration is accurate. As output increases, attenuate signal generator to keep maximum out- put at TP#1 to less than 1 volt. Repeat steps 6 and 7 until output is as high as possible. Use a strong signal from the FM generator. Adjust T-5 primary for minimum distortion. IF A DISTORTION ANALYZER IS NOT AVAILABLE, OMIT THIS STEP. DO NOT ADJUST T-5 PRIMARY. Observe direction of tilt of overall response curve at 105MC and 90MC. If direction is the same, adjust L-2 at 100MC for minimum tilt. Re-check tilt at 90MC and 105MC. If direction is not the same, adjust L-2 (at 90MC) and L-3 (at 105MC) for minimum tilt. Check tilt again at 100MC. With FM generator set for 2.5 microvolts output, place muting control to IN. Adjust the muting threshold control to the point at which the sine wave on the scope becomes erratic. Step 11 is an overall sensitivity check. It requires a distortion analyzer and FM signal generator with attenuator. With 2.5 microvolts input at the 300 ohm terminals, TP#1 voltage should be .45 volts or more. 3 RadioFans.CN 收音机爱 好者资料库 MAC 15 00 MULTIPLEX STEPS 1 2 3 4 5 6 7 8 TUNER DIAL SETTING Point of no interference or signal SAME 100MC SAME SAME SAME SAME SAME SIGNAL GENERATOR FREQ. Audio gener- ator set to 67KC 0.5 volts out- put or less MPX generator with 19KC pilot attenuated to approx. 5% level. (5% level is of normal 10% level). 19KC pilot MUST be at- tenuated for correct align- ment 100MC modu- lated by MPX generator. 19KC pilot at normal output SAME SAME SAME SAME Tune to a strong mono FM station COUPLING TP#2 SAME 300 ohm antenna termi- nals with matching net- work. (See * previous page) SAME SAME SAME SAME SAME MODULATION 1KC 100% modu- lation (34 KC deviation) modu- lating left or right only SAME SAME SAME Turn off 1 KC audio modulation INDICATOR TYPE Audio VTVM DC VTVM Audio VTVM Audio VTVM and scope SAME SAME SAME MPX stereo indi- cator light on receiver CONNECTED TO L or R tape output Pin 9 of 6EA8 Pin 1 or 2 of T-7 L or R tape output SAME SAME SAME 4 RadioFans.CN 收音机爱 好者资料库 DECODER ALIGNMENT ADJUST 67KC Trap (L-6) T-6 top and bottom; L-5 T-7 bottom core T-7 top core L-5 MPX light adjust control R-12 TEST LIMITS Adjust for mini- mum voltage Adjust for maxi- mum voltage SAME Adjust for stable scope display 30db separation or more SAME REMARKS Stereo light must be on. This is done by adjusting the MPX Light control, R-12. Adj. Stereo light must be off. Stereo light must be completely on. 1. Turn off 19KC pilot on MPX generator. 2. Adjust upper core of T-7 to obtain a stable and uniform 1 KC signal scope display. This adjustment may be critical, so turn core very slowly. 3. Turn 19KC pilot back on. Modulate left channel and measure right channel output. Adjust L-5 for minimum right channel output (maximum separation). Be sure all test leads are removed from TP#2 for separation tests. Modulate right channel and measure left channel output. Separation in steps 5 and 6 should be at least 30db. This step checks the rejection of 19KC and 38KC frequencies. Residual output should be at least 40db below modulated output. Turn control until light comes on. Then back off just enough to cause the light to go off. Then back off about 1/8 of a turn more. Light should operate ONLY on a MPX signal. 5 RadioFans.CN 收音机爱 好者资料库 6 RadioFans.CN 收音机爱 好者资料库 7 RadioFans.CN 收音机爱 好者资料库 PREAMP/AMP TESTS AND ADJUSTMENTS All adjustments should be made after a minimum of a 10 minute warm-up. 1 Remove the 12AX7 (V-9). 2 Measure the voltage at TP#3. Voltage should be 0.7 volts positive. If it is not 0.7 volts, ad- just R-8. 3 Do likewise with TP#4 and R-9, TP#5 and R-10, TP#6 and R-11. 4 Re-insert the 12AX7. 5 Feed a 1 KC signal into AUX. Drive the amp to full 30 watts output. Be sure all controls are set for a flat response. Check to be sure the channels have equal output with equal drive from the audio oscillator. If channels are un- balanced, adjust R-55, This control is found on the left preamp printed circuit board. It will vary the output of the left channel. The preamp cover must be removed to gain access to this control. 6 Measure harmonic distortion at 30 cycles. Ad- just R-6 for minimum distortion on the left channel and R-7 for the right. Distortion must be less than 0.5%. The bottom cover must be removed to adjust these controls. They have blue plastic knobs. 7 Now measure distortion at 2KC and 20KC. Must be less than 0.5% at full output. 8 Next, feed a signal thru the phono inputs. Check for correct RIAA equalization. 9 Remove all inputs. Check hum and noise on phono 1. Should be at least 60db below rated output. DIAL STRINGING 8 RadioFans.CN 收音机爱 好者资料库 MAC 1500 PARTS LIST TUBES ITEM NO. V-1 V-2 V-3 V-4 V-5 V-6 V-7 v-8 V-9 V-10 V-11 V-12 V-13 V-14 V-15 ITEM NO. Q-1 Q-2 0-3 Q-4 Q-5 Q-6 Q-7 Q-8 Q-9 Q-10 Q-11 Q-12 Q-13 Q-14 Q-15 0-16 Q-17 Q-18 Q-19 Q-20 ITEM NO. D-1 D-2 D-3 D-4 D-5 D-6 0-7 D-8 D-9 D-10 D-11 D-12 D-13 D-14 D-15 D-16 USE HF Amplifier Mixer 1st IF Amplifier 2nd IF Amplifier 3rd IF Amplifier, 1st Limiter 4th IF Amplifier, 2nd Limiter 19KC Amplifier, Indicator Control MPX 38KC Oscillator Voltage Amplifier Left Channel Driver Right Channel Driver Left Channel Output Left Channel Output Right Channel Output Right Channel Output TRANSISTORS USE Local Oscillator Control Amplifier MPX Lamp Control Oscillator On-Qff Control Left Channel Audio Amplifier Right Channel Audio Amplifier Left Channel Audio Amplifier Right Channel Audio Amplifier Left Channel Low Level Amplifier Right Channel Low Level Amplifier Left Channel Emitter Follower Right Channel Emitter Follower Left Channel Low Level Amplifier Right Channel Low Level Amplifier Left Channel Emitter Follower Right Channel Emitter Follower Left Channel Emitter Follower Right Channel Emitter Follower Left Channel Voltage Amplifier Right Channel Voltage Amplifier DIODES DESCRIPTION Diode Diode Diode Diode Diode Diode Matched pair 1N542) Diode (Matched pair 1N542) Diode (Matched pair 1N542 Diode (Matched pair 1N542 Diode (Matched pair 1N542 800 PIV 750MA Silicon Rectifier 600 PIV 750MA Silicon Rectifier 600 PIV 750MA Silicon Rectifier 800 PIV 750MA Silicon Rectifier 400 PIV 750MA Silicon Rectifier 10 V 400 MW Zener Rectifier TUBE NUMBER 6DS4 6DS4 6AU6 6AU6 6AU6 6CS6 6EA8 12AU7 12AX7 12AU7 12AU7 7591 7591 7591 7591 TRANSISTOR NUMBER TA2556/40244 2N3638 2N3391A 2N3391A 2N3391A 2N3391A 2N3391A 2N3391A 2N3391A 2N3391A 2N3391A 2N720A 2N720A 2N339IA 2N3391A 2N3391A 2N3391A 2N720A 2N720A DIODE NUMBER FD100 FD100 FD100 FD100 FD100 IN542 1N542 1N543 IN542 PART NUMBER 165-013 165-013 165-004 165-004 1 65-004 165-01 1 1 65-044 165-01 8 165-019 165-018 165-018 165-022 165-022 1 65-022 165-022 PART NUMBER 1 32-008 132-007 132-010 132-004 1 32-004 132-004 1 32-004 132-004 132-004 132-004 132-004 132-004 1 32-002 132-002 1 32-004 132-004 132-004 132-004 132-002 1 32-002 PART NUMBER 070-022 070-022 070-022 070-022 070-022 070-003 070-003 070-003 070-003 070-003 070-017 070-016 070-016 070-017 070-015 070-011 9 RadioFans.CN 收音机爱 好者资料库 CONTROLS ITEM NO. R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 R-9 R-10 R-11 R-12 R-55 FUNCTION Balance Control Bass Control Treble Control Volume Control Muting Adjust Control Driver Balance Control Driver Balance Control Bias Adjust Control Bias Adjust Control Bias Adjust Control Bias Adjust Control MPX Light Adjust Control Left Channel Gain Control RESISTANCE 500K-500K IM-1M 500K-500K 60K-60K 100K 5K 5K 100K 100K 100K 100K 100K 5K PART NUMBER 134-165 134-117 134-118 134-164 134-102 134-103 134-103 134-102 134-102 134-102 134-102 134-102 134-120 SWITCHES ITEM NO. S-1 FUNCTION Rotary Switch SS-26 19/32 Trigger Slide Switch SS-50 7/32 Trigger Slide Switch SS-50 19/32 Trigger Slide Switch (S used) DESCRIPTION Input Selector Muting On -Off Speaker On -Off Stereo/Mono, Tape Monitor, LF and HF Fillers, Loudness. PART NUMBER 1 46-096 148-003 148-006 1 48-007 TRANSFORMERS ITEM NO. T-1 T-2 T-3 T-4 T-5 T-6 T-7 T-8 T-9 T-10 Ml FUNCTION FM-IF FM- IF FM-IF IF (Muting) FM Discriminator 19KC Amplifier 38KC Oscillator Balun Output (Left) Output (Right) Power PART NUMBER 162-005 162-004 162-004 162-029 1 62-027 162-010 162-009 076-006 159-062 159-062 159-061 CAPACITORS 10 ITEM NO. C-1 C-2 C-3 C-4 C-5 C-6 C-7 C-8 C-9 C-10 C-11 C-13 C-16 C-17 C-18 C-19 C-20 C-21 C-22 C-23 C-24 C-27 C-28 C-29 C-30 DESCRIPTION Variable FM Trimmer (Ceramic) Trimmer (Ceramic) Trimmer (Glass) Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Feed -Thru Ceramic Feed-Th r u Ceramic Disc. Ceramic Tubular Ceramic Disc. Ceramic Disc. Ceramic Tubular Ceramic Disc. Ceramic Feed-Th ru Ceramic Feed-Thru Ceramic Feed-Thru Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Feed -Thru Ceramic Feed-Thru Ceramic Disc. Ceramic Disc. CAPACITANCE 1-8 PF 1-8 PF .005MFD .001 MFD .001 MFD .001MFD .001MFD 10PF 5PF .005 10PF 3PF 10PF .001 MFD .001MFD .001 MFD .005MFD 10PF .005 MFD .001 MFD .001MFD .005MFD .01 MFD TOLERANCE +80-20% 20% NPO .25PF N150 +80-20% 20% NPO .25PF 20% NPO +8020% 20% NPO +80-20% +80-20% +80-20% PART NUMBER 059-006 060-001 060-001 060-002 061-040 061-035 061-035 061-036 061-036 061-009 061-005 061-040 061-009 061-003 061-009 061-036 061-036 061-036 061-040 061-009 061-040 061-036 061-036 061-040 061-043 RadioFans.CN 收音机爱 好者资料库 CAPACITORS HEM NO. C-31 C-32 C-33 C-34 C-35 C-36 C-37 C-38 C-40 C-41 C-42 C-43 C-44 C-45 C-46 C-47 C-48 C-49 C-50 C-51 C-52 C-53 C-54 C-55 C-56 C-57 C-58 C-59 C-60 C-61 C-62 C-63 C-64 C-65 C-66 C-67 C-68 C-69 C-70 C-71 C-72 C-73 C-74 C-75 C-76 C-77 C-7B C-79 C-80 C-81 C-82 C-83 C-84 C-85 C-86 C-87 C-88 C-89 C-90 C-91 C-92 C-93 C-94 C-95 C-96 C-97 C-98 C-99 C-100 C-101 C-102 C-103 C-104 C-105 C-106 C-107 C-108 C-109 C-110 C-111 C-112 C-113 DESCRIPTION Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Tubular Flat Foil Ceramic Feed-Thru Ceramic Feed-Thru Ceramic Feed-Thru Ceramic Feed-Thru Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Feed -Thru Ceramic Disc. Silver Mica Ceramic Disc. Ceramic Disc, Ceramic Disc. Ceramic Disc. Silver Mica Silver Mica Electrolytic Ceramic Disc. Ceramic Disc. Silver Mica Silver Mica Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Tubular Ceramic Tubular Ceramic Disc. Ceramic Disc. Flat Foil Flat Foil Ceramic Disc. Flat Foil Flat Foil Ceramic Disc. Ceramic Disc. Electrolytic Electrolytic Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Disc. Ceramic Tubular Ceramic Tubular Flat Foil Flat Foil Flat Foil Flat Foil Molded Film Molded Film Electrolytic Electrolytic Mylar Mylar Ceramic Disc. Ceramic Disc. Flat Foil Flat Foil Electrolytic Electrolytic Ceramic Disc. Ceramic Disc. Mylar Mylar Mylar Mylar Mylar Mylar Ceramic Tubular Ceramic Tubular CAPACITANCE 12PF .1MPD .005MFD .005MFD .01 MFD 15PF .1MFD .001 MFD .001 MFD .001 MFD .001 MFD .1MFD .005MFD .005MFD 6.8PF 12PF 47PF 100PF .02MFD .0027MFD 100PF .001MFD .001MFD .02MFD .0012MFD .0012MFD 100MFD _1MFD 220PF .0047MFD .0047MFD .005MFD .005MFD .005MFD .005MFD 330PF 330PF 430PF 430PF .01 MFD .01 MFD .22MFD .22MFP 10PF .22MFD .22MFD .1MFD .1MFD