HarmanKardon-TU940-tun-sm维修电路原理图.pdf

The Harman Kardon Model TU-940 Manual A AM/FM STEREO DIGITAL RDS TUNER CONTENTS LEAKAGE TEST.2 SPECIFICATIONS.3 CONTROL AND FUNCTIONS4 BLOCK DIAGRAM7 DISASSEMBLY PROCEDURES8 CIRCUIT DESCRIPTION.13 ALIGNMENT PROCEDURES.16 GENERAL UNIT EXPLODED VIEW.21 PRINTED CIRCUIT BOARDS.22 ELECTRICAL PARTS LIST.24 IC FUNCTIONAL BLOCK DIAGRAM.32 PACKAGE33 WIRING DIAGRAM35 SCHEMATIC DIAGRAMS.36 harman/kardon Parts and Service Office 80 Crossways Park West, Woodbury, N.Y. 11797 Printed in Korea LOCAL DXRDS PTY RT CT TA EON TUNED STEREO MONO TUNING PRESET RF LEVELSTANDBY WIDE NARROW CLOCK TIMERON OFFSLEEPAUTOMEMORY SCAN Power 12345 67890 Band Auto/Man IF BandDisplay Mode Memory TU 940 RDS Tune/PstPst Scan Remote sensorDisplayPTY DirectCharacter Tuning RF Mode FM Mode RadioFans.CN LEAKAGE TEST Before returning the unit to the user, perform the following safety checks: 1. Inspect all lead dress to makes certain that leads are not pinched or that hardware is not lodged between the chassis and other metallic parts in the unit. 2. Be sure that any protective devices such as nonmetallic control knobs, insulating fishpapers, cabinet backs, adjustment and compartment covers or shields, isolation resistor-capacity networks mechanical insulators, etc. Which were removed for servicing is properly reinstalled. 3. Be sure that no shock hazard exists; check for leakage current using Simpson Model 229 Leakage Tester, standard equipment item no. 21641, RCA model WT 540A or use alternate method as follows: plug the power cord directly into a 230-volt AC receptacle ( do not use an isolation transformer for this test.). Using two clip leads, connects a 1500 ohm, 10-watt resistor paralleled by a 0.15 F capacitor, in series with all exposed metal cabinet parts and a known earth ground such as a water pipe or conduit. Use a VTVM or VOM with 1000 ohms per volt, or higher sensitivity to measure the AC voltage drop across the resistor. (This test should be performed with the power switch in both the on and off positions.) A reading of 0.35 volt RMS or more is excessive and indicates a potential shock hazard which must be corrected before returning the unit to the owner 2 RadioFans.CN SPECIFICATION FM SECTION Nominal Limit Test Condition: 40 kHz DEV., 1kHz Frequency. Tuning Range/Step 87.5 MHz 108 MHz/50 kHz Usable Sensitivity (-26dB S/N) Mono 8.15 dBf 12.25 dBf Limiting Sens at 3 dB 7.2 dBf 9.2 dBf 50dB Quieting Sens Mono 16.2 dBf 19.2 dBf Stereo 39.2 dBf 42.8 dBf Total 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 dB Stereo Separation at 98 MHz ( NORMAL) 1kHz 50 dB 40 dB 10kHz 40 dB 35 dB Muting and Automatic Tereshold at 98 MHz 31.2 6 2 dBf 31.2 6 4 dBf Auto Stop Level 31.2 6 2 dBf 31.2 6 4 dBf Selectivity NORMAL/NARROW 6 300 kHz 50/70 dB 34/60 dB Auto Scan Error 6 15 kHz 6 20 kHz Frequency Response at 30 Hz 15 kHz 6 0.5 dB + 1/22.5 dB Image Rejection at 106 MHz 80 dB 65dB AM Suppression 60 dB 50 dB RDS Sensitivity 31.2 6 2 dBf 31.2 6 4 dBf Output Voltage Mono 5006100mV 5006150mV DIMENSIOS (W H D) 442 92 350 WEIGHT 3.9 Kg POWER SUPPLIES AC 230 V, 5- Hz POWER CONSUMPTION 15W These specifications are service target specs. Specifications and components are subject to change without notice. Overall performance will be maintained or improved. AM SECTION Nominal Limit Test Condition: 400 Hz, 30% Modulation Tuning Range/Step MW 522 kHz 1611 kHz/9 kHz Usable Sensitivity (2 20 dB S/N) MW: 594 kHz, 1404 kHz 500 mV 800 mV Signal to Noise Ratio (0.1 V INPUT) MW: 999 kHz 55dB 48 dB Frequency Response at 2 6 dB MW 160 Hz 2.5 kHz 150 Hz 2 kHz Selectivity at 6 9 kHz MW: 999 kHz 35dB 30 dB A.G.C. Figure of merit at 999 kHz 50 dB 45 dB Image Rejection MW: 1404 kHz 40 dB 35 dB Total 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 dB Output Voltage ( 5mV INPUT) 165 6 30 mV 165 6 40 mV 3 RadioFans.CN CONTROL AND FUNCTIONS 1. POWER Press to turn the unit on. The ring around the button will glow green. Press again to turn the unit off. The ring will glow red and the word “STANDBY” will appear in the display. 2. NUMBERIC KEYS Use to select the preset number of a station that has been entered into the preset memories or to store a station in the memory in conjunction with MEMORY 7. To recall a previously programmed station, press the appropriate numeric button(s). For single digit 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 be tuned at once. To use the buttons to enter a station to the preset memory, see page 10. 3. FLUORESCENT DISPLAY The display panel contains a large display for station frequency information and RDS data, as well as status indicators for various tuner functions and 5-step RF level indicator bars. 4. BAND Press 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 interference form adjacent station. NARROE: When reception is disturbed by interference from other stations, press until NARROW is lit. This improves reception. NORMAL: For normal reception, press until NORMAL is lit. 6. DISPLAY MODE Press to change between bright and dim display lighting or display off. LOCAL DXRDS PTY RT CT TA EON TUNED STEREO MONO TUNING PRESET RF LEVELSTANDBY WIDE NARROW CLOCK TIMERON OFFSLEEPAUTOMEMORY SCAN Power 12345 67890 Band Auto/Man IF BandDisplay Mode Memory TU 940 RDS Tune/PstPst Scan Remote sensorDisplayPTY DirectCharacter Tuning RF Mode FM Mode 456789 101112141315161732 1 4 7. MEMORY Use to enter station into the preset memory or to start the Auto Preset Memory function. The memory indicator blinks when the button is pressed. See page 10 for instructions on using the memory system. 8. TUNE/P.SET Press to light PRESET indicator. When the indicator is lit, the TUNING knob 10 can be used to step through the preset stations in ascending or descending order. When the PRESET indicator is not lit, normal tuning (auto or manual) is activated. 9. P.SET SCAN Press 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. TUNING This knob has a number of functions, although its primary use is to select stations. In normal use, turn the knob in either direction to move through the selected band to find a station. When the 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 the tuning knob clockwise will cause the tuner to scan higher frequencies. When turned counterclockwise, lower frequencies will be scanned. The tuner will stop at the first station that has acceptable signal strength. Turn the knob again in the same direction to tune to the next available station. When TUNE/P.SET 8 is pressed so that the PRESET indicator is lit, turning the TUNING knob 10 will move the tuner up or down through the stations programmed into the units memory. The Tuning Knob also functions as a selector for PTY 12 and Character 11 functions. See descriptions of these functions on page 13 and below. 11. CHARACTER Permits 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 memory location (1-30) using the NUMBER keys 2. The name may be called up at any time by pressing DISPLAY 14. 12. PTY Press to select a particular PTY (Program Type) according to the information transmitted by an RDS station. After pressing PTY, turn the TUNING knob 10 to select the program type for which you wish to search. For detailed RDS information, see page 12. 5 13. DIRECT Pressing this button will start the sequence for direct entry of a stations frequency. After pressing the button simply press the proper Numeric Keys 2 to tune the station. For more information see next page. 14. DISPLAY Press to display current frequency, station name or RDS information. Press again to move to the 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: Station Name, 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 next to the red RDS indicator in the display: PTY (Program Type), RT (Radio Text) or CT (Clock Time) will light up, if the station is broadcasting this information. The RDS information available will vary. 15. FM MODE Press to change mode of FM reception. Press so that the MONO indicator is not lit and all stations received with a signal strength high enough for acceptable audio performance will be heard, either in stereo (the red stereo indicator is 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 be heard in mono. NOTE: When experiencing weak or noisy reception of a stereo broadcast, reception quality may be 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 strong stations 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 reduce intermodulation noise and provide better sound quality. When tuning distant stations, press so that the local indicator is not lit. This improves the tuners ability to receive weak signals with lower noise, and when needed press the FM MODE button 15 until the MONO indicator is lit to make weak station audible. 17. AUTO/MANUAL Press so that the AUTO indicator is lit to engage the automatic tuning system. When in the AUTO mode, turning the TUNING knob 10 cause the tuner to scan for the next available station with sufficient signal strength and stop. Turn the Tuning knob again to continue through the frequency band to the next station. 6 7 DISASSEMBLY PROCEDURES 8 9 10 11 12 13 CIRCUIT DESCRIPTION 1. 14 2. Pin Functions Pin No. ConfigurationSymbolDescription 1- 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.VssGround 21P17AM 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! 33VssVssGround 34/35X1/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)GNDGround 49P72RDSInput 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. 15 3. ALIGNMENT PROCEDURES 1. 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 Modulator Note: Remove FM external antenna from terminal when aligning. 2. Alignment and Test Points Refer to Adjustment Location on page 12 Note: As a front-end (FE 101) is difficult to repair if faulty, replace it with new one. 16 FM SECTION Standard Setting of FM Stereo RF Signal Generator. STEREO STANDARD SIGNALMONAURAL STANDARD SIGNAL Carrier 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 Distortion 4. 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 Adjustment Procedure: 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. 17 FM Tuned Indication Lighting Level Adjustment Procedure: 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 Adjustmen