HarmanKardon-TU940-tun-sm维修电路原理图.pdf

The Harman KardonModel TU-940 Manual AAM/FM STEREO DIGITAL RDS TUNERCONTENTSLEAKAGE TEST.2SPECIFICATIONS.3CONTROL AND FUNCTIONS4BLOCK DIAGRAM7DISASSEMBLY PROCEDURES8CIRCUIT DESCRIPTION.13ALIGNMENT PROCEDURES.16GENERAL UNIT EXPLODED VIEW.21PRINTED CIRCUIT BOARDS.22ELECTRICAL PARTS LIST.24IC FUNCTIONAL BLOCK DIAGRAM.32PACKAGE33WIRING DIAGRAM35SCHEMATIC DIAGRAMS.36 harman/kardonParts and Service Office80 Crossways Park West, Woodbury, N.Y. 11797 Printed in KoreaLOCAL DXRDS PTY RT CT TA EON TUNED STEREO MONO TUNING PRESETRF LEVELSTANDBY WIDE NARROW CLOCK TIMERON OFFSLEEPAUTOMEMORY SCANPower1234567890BandAuto/ManIF BandDisplayModeMemoryTU 940 RDSTune/PstPst ScanRemote sensorDisplayPTYDirectCharacterTuningRF Mode FM ModeRadioFans.CN 收音机爱 好者资料库LEAKAGE TESTBefore returning the unit to the user, perform thefollowing safety checks:1. Inspect all lead dress to makes certain that leadsare not pinched or that hardware is not lodgedbetween the chassis and other metallic parts in theunit.2. Be sure that any protective devices such asnonmetallic control knobs, insulating fishpapers,cabinet backs, adjustment and compartment coversor shields, isolation resistor-capacity networksmechanical insulators, etc. Which were removed forservicing is properly reinstalled.3. Be sure that no shock hazard exists; check forleakage current using Simpson Model 229 LeakageTester, standard equipment item no. 21641, RCAmodel WT 540A or use alternate method as follows:plug the power cord directly into a 230-volt ACreceptacle ( do not use an isolation transformer forthis test.). Using two clip leads, connects a 1500ohm, 10-watt resistor paralleled by a 0.15 Fcapacitor, in series with all exposed metal cabinetparts and a known earth ground such as a waterpipe or conduit. Use a VTVM or VOM with 1000ohms per volt, or higher sensitivity to measure theAC voltage drop across the resistor. (This testshould be performed with the power switch in boththe on and off positions.)A reading of 0.35 volt RMS or more is excessiveand indicates a potential shock hazard which mustbe corrected before returning the unit to the owner2RadioFans.CN 收音机爱 好者资料库SPECIFICATIONFM SECTION Nominal LimitTest Condition: 40 kHz DEV., 1kHz Frequency.Tuning Range/Step 87.5 MHz 108 MHz/50 kHzUsable Sensitivity (-26dB S/N) Mono 8.15 dBf 12.25 dBfLimiting Sens at 3 dB 7.2 dBf 9.2 dBf50dB Quieting Sens Mono 16.2 dBf 19.2 dBf Stereo 39.2 dBf 42.8 dBfTotal Harmonic Distortion Mono 0.1% 0.25% Stereo 0.15% 0.35%Signal to Noise Ratio (1mV RF INPUT) Mono 80 dB 75dB Stereo 75 dB 70 dBStereo Separation at 98 MHz ( NORMAL)1kHz 50 dB 40 dB10kHz 40 dB 35 dBMuting and Automatic Tereshold at 98 MHz 31.2 6 2 dBf 31.2 6 4 dBfAuto Stop Level 31.2 6 2 dBf 31.2 6 4 dBfSelectivity NORMAL/NARROW 6 300 kHz 50/70 dB 34/60 dBAuto Scan Error 6 15 kHz 6 20 kHzFrequency Response at 30 Hz 15 kHz 6 0.5 dB + 1/22.5 dBImage Rejection at 106 MHz 80 dB 65dBAM Suppression 60 dB 50 dBRDS Sensitivity 31.2 6 2 dBf 31.2 6 4 dBfOutput Voltage Mono 5006100mV 5006150mVDIMENSIOS (W H D) 442 92 350WEIGHT 3.9 KgPOWER SUPPLIES AC 230 V, 5- HzPOWER CONSUMPTION 15WThese specifications are service target specs.Specifications and components are subject to change without notice.Overall performance will be maintained or improved.AM SECTION Nominal LimitTest Condition: 400 Hz, 30% ModulationTuning Range/Step MW 522 kHz 1611 kHz/9 kHzUsable Sensitivity (2 20 dB S/N) MW: 594 kHz, 1404 kHz 500 mV 800 mVSignal to Noise Ratio (0.1 V INPUT) MW: 999 kHz 55dB 48 dBFrequency Response at 2 6 dB MW 160 Hz 2.5 kHz 150 Hz 2 kHzSelectivity at 6 9 kHz MW: 999 kHz 35dB 30 dBA.G.C. Figure of merit at 999 kHz 50 dB 45 dBImage Rejection MW: 1404 kHz 40 dB 35 dBTotal Harmonic Distortion ( 0.1 V INPUT) MW: 999 kHz 0.7% 1.2 %Tuned Level MW: 999 kHz 800 mV 6 3 dB 800 mV 6 5 dBOutput Voltage ( 5mV INPUT) 165 6 30 mV 165 6 40 mV3CONTROL AND FUNCTIONS1. POWERPress to turn the unit on. The ring around the button will glow green. Press again to turn the unitoff. The ring will glow red and the word “STANDBY” will appear in the display.2. NUMBERIC KEYSUse to select the preset number of a station that has been entered into the preset memories orto store a station in the memory in conjunction with MEMORY 7.To recall a previously programmed station, press the appropriate numeric button(s). For singledigit numbers (1-9), press the number and the station will be tuned at once or in a few seconds.To recall preset locations 10 though 30, press the desired buttons in order and the station will betuned at once.To use the buttons to enter a station to the preset memory, see page 10.3. FLUORESCENT DISPLAYThe display panel contains a large display for station frequency information and RDS data, aswell as status indicators for various tuner functions and 5-step RF level indicator bars.4. BANDPress to change between FM and AM frequency bands.5. IF BAND (FM TUNING ONLY)Press to change the passband of the intermediate frequency to compensate for interferenceform adjacent station.NARROE: When reception is disturbed by interference from other stations, press untilNARROW is lit. This improves reception.NORMAL: For normal reception, press until NORMAL is lit.6. DISPLAY MODEPress to change between bright and dim display lighting or display off.LOCAL DXRDS PTY RT CT TA EON TUNED STEREO MONO TUNING PRESETRF LEVELSTANDBY WIDE NARROW CLOCK TIMERON OFFSLEEPAUTOMEMORY SCANPower1234567890BandAuto/ManIF BandDisplayModeMemoryTU 940 RDSTune/PstPst ScanRemote sensorDisplayPTYDirectCharacterTuningRF Mode FM Mode4567891011121413151617321 47. MEMORYUse to enter station into the preset memory or to start the Auto Preset Memory function. Thememory indicator blinks when the button is pressed. See page 10 for instructions on using thememory system.8. TUNE/P.SETPress to light PRESET indicator. When the indicator is lit, the TUNING knob 10 can be used tostep through the preset stations in ascending or descending order. When the PRESET indicatoris not lit, normal tuning (auto or manual) is activated.9. P.SET SCANPress to automatically step through each of the stations that has been preset into the memory.Each programmed station will play for approximately five seconds. To stop at a desired station,press again, while the station is playing.10. TUNINGThis knob has a number of functions, although its primary use is to select stations. In normaluse, turn the knob in either direction to move through the selected band to find a station. Whenthe TUNED indicator lights, the station is properly locked in.A number of automated tuning methods are also available:In the FM mode, when AUTO/MAN 17 is pressed so that the AUTO indicator is lit, turning thetuning knob clockwise will cause the tuner to scan higher frequencies. When turnedcounterclockwise, lower frequencies will be scanned. The tuner will stop at the first station thathas acceptable signal strength. Turn the knob again in the same direction to tune to the nextavailable station.When TUNE/P.SET 8 is pressed so that the PRESET indicator is lit, turning the TUNING knob10 will move the tuner up or down through the stations programmed into the units memory. TheTuning Knob also functions as a selector for PTY 12 and Character 11 functions. Seedescriptions of these functions on page 13 and below.11. CHARACTERPermits you to enter or modify the name of any station, which is not broadcasting in RDS.To enter a name, press CHARACTER once. A line will flash under the first space in the display,Turn the tuning knob until the desired character (letter, number or symbol) appears.Press again to move to the next space. Repeat this procedure until the name is spelled out,using the tuning knob to select a character and the Character button to move to the next space.When the last character has been programmed, press MEMORY 7, and then select memorylocation (1-30) using the NUMBER keys 2.The name may be called up at any time by pressing DISPLAY 14.12. PTYPress to select a particular PTY (Program Type) according to the information transmitted by anRDS station. After pressing PTY, turn the TUNING knob 10 to select the program type for whichyou wish to search.For detailed RDS information, see page 12.513. DIRECTPressing this button will start the sequence for direct entry of a stations frequency. Afterpressing the button simply press the proper Numeric Keys 2 to tune the station. For moreinformation see next page.14. DISPLAYPress to display current frequency, station name or RDS information. Press again to move tothe next item in the following order:If a non-RDS-station is tuned:Frequency, station name (if a name is entered manually). If an RDS station is tuned: StationName, Band and Frequency, Program Type (PTY), Radio Text, Time.If an RDS station is tuned (only FM) indicators for available RDS information will be shown nextto the red RDS indicator in the display: PTY (Program Type), RT (Radio Text) or CT (ClockTime) will light up, if the station is broadcasting this information. The RDS information availablewill vary.15. FM MODEPress to change mode of FM reception.Press so that the MONO indicator is not lit and all stations received with a signal strength highenough for acceptable audio performance will be heard, either in stereo (the red stereo indicatoris lit) or in mono, just as they are transmitted. The sound of all weaker stations will be muted.Press so that the MONO indicator is lit and all stations, including all stereo transmissions, will beheard in mono.NOTE: When experiencing weak or noisy reception of a stereo broadcast, reception quality maybe improved by pressing FM MODE to switch to mono.16. RF MODE (FM TUNING ONLY)Press to compensate for RF intermodulation noise caused by interference from other strongstations in your area.In urban areas or with cable systems where reception is strong and there are many stations,press until LOCAL indicator is lit, This will attenuate the signal strength of all stations received( RF LEVEL indicator bars in the display will show lower signal strength) and thus may reduceintermodulation noise and provide better sound quality.When tuning distant stations, press so that the local indicator is not lit. This improves the tunersability to receive weak signals with lower noise, and when needed press the FM MODEbutton 15 until the MONO indicator is lit to make weak station audible.17. AUTO/MANUALPress so that the AUTO indicator is lit to engage the automatic tuning system. When in theAUTO mode, turning the TUNING knob 10 cause the tuner to scan for the next available stationwith sufficient signal strength and stop. Turn the Tuning knob again to continue through thefrequency band to the next station.67DISASSEMBLY PROCEDURES8910111213CIRCUIT DESCRIPTION1.142.Pin FunctionsPin No. ConfigurationSymbolDescription1- 7FIP1- FIP7G1- G7Grid signal output for FIP.8VDDVDD+5V Power supply.9- 14P22- P27N.C.Not used!15P21E. UPInput to detect encoder UP signal.16P20E. DOWNInput to detect encoder DOWN signal.17RESETRESETInput to reset CPU.(At L, it is active)18P74N.C.Not used!19P73PDInput to detect power down.(At L, it is active)20A.VssA.VssGround21P17AM Input to select step for AM tuning.(H:9KHz,L:10KHz)22P16FMInput to select step for FM tuning.(H:50KHz,L:100KHz)23/24P15/P14N.C.Not used!25- 27P11- P13KEY INData input for key scan.28P10S_METERInput to detect the receiving signal level.29A.VddA.Vdd+5V Power supply.30A.VrefA.VrefReferance voltage for A/D converter.(Connected to 5V,not VDD)31P04N.C.Not used!(Connected to ground)32XT2N.C.Not used!33VssVssGround34/35X1/X2X1/X2Input and output for 4.19MHz crystal.36P37N.C.Not used!37P36STEREOInput to light STEREO indicator.(At H,it is active)38P35TUNEDInput to detect station during tuning.If L is inputed during tuning, tuning stop at that frequency.When power is on, control data output is L.39P34POWERWhen power is off, control data output is H and last memory function is activated.40P33MUTEOutput for mute.(At H,it is active)41P32CEChip enable output for LC7218JM.42/43P31/P30DA/CKData/Clock output for LC7218JM.44P03DOData input for LC7218JM.45P02RMC INInput to receive remote control data from amplifier.46/47P01/P00RDS DA/CKInput to receive RDS clock/data from TDA7479D.48IC(Vpp)GNDGround49P72RDSInput to select RDS function for europe.(At H,RDS function is selected)50/51P71/P70P_LED CTRL1/2 Output for power LED.Standby(1:L,2:H) or power on(1:H,2:L)52VDDVDD+5V Power supply.53FIP33N.C.Not used!54- 70 FIP16- FIP32S3- S19Segment signal output for FIP.71VloadVloadPower supply for FIP Controller.72/73FIP15/FIP14S1/S2Segment signal output for FIP.74- 80FIP7- FIP13G8- G14Grid signal output for FIP.153.ALIGNMENT PROCEDURES1. Equipment Required AM Standard Signal Generator (AM SSG.) Audio Generator Oscilloscope Distortion Meter AC Voltmeter DC Voltmeter FM Standard Signal Generator(FM SSG.) Frequency Counter Stereo ModulatorNote: Remove FM external antenna from terminal when aligning.2. Alignment and Test Points Refer to Adjustment Location on page 12Note: As a front-end (FE 101) is difficult to repair if faulty, replace it with new one.16FM SECTION Standard Setting of FM Stereo RF Signal Generator.STEREO STANDARD SIGNALMONAURAL STANDARD SIGNALCarrier frequency 98 MHz.Modulation: Audio 1 kHz, 40 kHz deviation. Pilot 19 kHz, 7.5 kHz deviation.98 MHz.1 kHz, 40 kHz deviation.FM Discriminator Adjustment(NULL and MONO Distortion)Procedure:1. Tune the set to 98 MHz.2. Adjust L302 to obtain 0V between TP301 3 reading on the VOM. .NULL.3. Adjust L200 for a minimum reading on the distortion meter .MONO Distortion4. Repeat adjustments in step 2 and 3 several times until optimum measurements are obtained.Note: When replacing the ceramic filter, perform this alignment.FM Stereo Distortion AdjustmentProcedure:1. Tune the set to 98MHz. Set FM SSG. output level to 1mV (60dB).2. Adjust IFT in FE401 for a minimum reading on the distortion meter.17FM Tuned Indication Lighting Level AdjustmentProcedure:1. Tune the set to 98MHz. Set FM SSG. output level to 20dB.2. Adjust VR301 to the point that the “TUNED” indicator begins to illuminate.FM Signal Level AdjustmentProcedure:1. Tune the set to 98MHz.2. Adjust VR401 and VR402 to light all RF Level Bars on the display. NORMAL: VR402 NARROW: VR401FM Stereo Separation Adjustment18Procedure:FM Stereo signalgenerator outputchannelVTVMConnectionVTVM reading (dB)L-CH.L-CH.R-CHL-CH.Adjust VR 102minimum reading.R-CHR-CHL-CH.R-CHAdjust VR 102 forminimum reading. L-CH. Stereo separation: - R-CH Stereo separation: - IF BAND SwitchNORMAL: Adjust VR 201NARROW: Adjust VR 202The separation of both channels should be equal.AM SECTIONAM VT Adjustment1. Set to AM 522 kHz and adjust L502 so that voltage of TP401 becomes 1.25V 0.1V2. Set to AM 1611 kHz and adjust CT 502 so that voltage of TP 401 becomes 8.5 0.1V3. Repeat the above adjustments 1 and 2.19AM Tracking Adjustment1. Set to AM 603 kHz and adjust L 501 to maximize AUDIO output level.2. Set to AM 1404 kHz and adjust CT 501 to maximize AUDIO output level.3. Set to AM 999 k