Roberts-1650-tape-sm 维修电路原理图.pdf

SERVICE MANUAL 1B40-1B50-1BBDD-1B70 TAPE RECORDERS _;. ,IMJ $2.50 RadioFans.CN 收音机爱 好者资料库MODELS 1640, 1650, 16600, 1670. !KEYED TO ILLUSTRATION AT RIGHT! 1. Supply Reel Holder 2. Supply Reel 3. l eft Channel Spcocr (Not in 1660D. Outboard In 1670) 4. Tope Guide Roller 5. Automatic Shut-Off lever 6. Drive Cop1tan Storage Post 7. Index Counter 8. Editing Guide 9. Take-up Reel Holder I 0. Toke-up Reel I I . Right (ronnel Speaker (Not in 1660D. Outboard in 1670) 1 2. Drive Capstan 13. Pinch Wheel 14. Paue lever 15. Rewid/ Fasl Forward Control 16. Stop/ Storl Con1rol 17. l eft Channel Miaophonc Input, 18. Right Channel Microphone Input 19. l eft Channel Volume Control 20. left Channel VU Meter (Oual Purpose Meter on Madel 1640) 21. Modl!l 1640: left/ Righi VU Meier Switch Model. 1650 and 1670: Monilor-NormaiMule Speqkcr Switch Model 1660D: R/ l - NOII!IOI l / R Channel Transfer Switch 22. Right Channel VU Meter (Not in Model 1640) 23. Right Channel Volume Control 24. Left Channel Play/ Record Switch 25. Right Channel Ploy/ Record Switch 26. Tone Control 27. Power Switch 28. Record Indicator light 29. Power Cord Connection 30. Stereo Headphone Jock ( 1650 & 1670 J 3 1. Right Hum Adjustment 32. left Hum Adjustment 33. Right ChoM cl Preornp Output ( 1640, 1650, 1670 I 34. lC!ft Chonnel Pr,omp Output (1640, 1650, 1670) 35. Right Channel Phono/ Rodio Input 36. lei I Channel Phon of Radio Input 37. Righi Channel Speaker Output (I 640. 1650, 1670) 38. Left Channel Speaker Output ( 1640, 1650, 1670) 39. Right Channel Tweeter Oulpul ( 1650, 1670) 40. Loll Channel TwDetcr Output (1650, 1670) 4 1. Righi Cho nnol High Levol Output II660D only) 4 2. lei I Cllonnol High Level Output ( 1660D only) 43. Righi Channel Low Level Output ( 16600 only) 44. lell Chonnal low l evel Output ( 1660D only) IDENTIFICATION CHART LlV)-, ll)l-=-=- RadioFans.CN 收音机爱 好者资料库FUNCTIONS OF CONTROLS Power Switch: Moving Lhe power switch to the ON posilion applies power to the motor and amplifier. In the OFF position, power is cut off to the entire unit. Volume: A separate volume control is provided for each channel. The volume control varies the playback volume, and the record level when making a recording. Tone: The tone control setting determines the reguency re-sponse of both amplifiers. Tone controls do nut. work during record. VU Meters: The VU Meters are used to monitor the record level when recording, and to balance stereo play. Meter indication should be between - 3 and -7 for best recording results. Record Switches: To operate, depress either or both record switches, then turn the stop/start conhol to start. . This holds the record switch in record mode. When the stop/start control is returned to stop, the record switch automatically snaps back to play mode_ Channel Transfer Switch: (1660-D) This switd1 internally transfers the output of one chan-nel over to the input of the other channel. A microphone or radio/ phono addition is added to the transfer receiv-ing channel during recording. The process may be repeated back and forth between channels to make a multiple recording. Tape Lifter: The tape lifter is under the head cover and is operated by the stop/start control. When the stop/start control is in stop mode, the lifter pushes the tape away from the heads to prevent excessive wear during the fast rewind and fru;t forward operations. This also mules the ound during these modes. Stop-Start: Starts tape movement i11 Play or Record position. Stops tape movement when moved lo the Stop position. Rewind-Fast Forward: Fast Forward position advances U1e tape onto the take-up reel at a fast rate of speed. Rewind position winds the tape onto the feed reel at a fast rate of speed. Pause Lever: In t.he Up posilion, pinch roller is moved away from capstan, and take-up torque is removed from take-up spin-dle. Tape stops instantly. This permits an adjustment of the record level without tape movement. Vhen lever is re-tmned to Down position, the tape movement begins. Index Counter: Provides a means of locating desired selections on a reel of tape without skipping and hunting. Hum Adjustment Controls: On Lhe lear paneL next to lhe A.C. Receptacle are two openings, these are the Right and Left Channel hum ad-justing Potentiometers. They are screw driver adjustment. Without tape on the unit, turn the volume up full and ad-just the controls for minimum hum on each channel. Auto-Stop Switch: When tape holds the auto-stop switch Up, the motor circuit is completed and the motor runs. If the tape breaks, runs out, is of insufficient tension, the switch lever fails, breaking the circuit, shutting off the motor. INPUT AND OUTPUT JACKS Microphones: A micropho11e input is provided for each channel. These input jacks are located on the front panel to the left of the left channel volume control. Note: When using the Phone-Radio inputs, the mi-crophone plugs must be removed from the mi-crophone jacks. Phono-Radio Input: Each channel is provided with a Phono-Raclio input for making direct recordings from a radio. phonograph, or tuner. These inputs are located on the rear panel. Outputs: 1660D . There are two high and two low level preamp outputs. each adjustable by the volume controls. These out-puts are used to collllect the 1ecorcler playback system to an external power amplifier. The output jacks are located on the rear panel. The high level outputs are used with standard tube type amplifiers that have tu_ner, auxiliary or other high level inputs. The low level outputs are for solid state amplifiers. Te5ts will show which is best for each individual case. The high and low level outputs are low impedance cath-ode follower outputs allowing for lvnger interconnecting c.:ables without line losses. 1640 . On the rear (Janel are two external speaker jacks and two high impedance preamp outputs. 1650 & 1670 . . . Has the same outputs as the 1640, plus two phono type jacks for extension speakers to work with the internal speakers. There is also a stereophone jack. 3 4 PARTS IDENTIFICATION Fig. 2. Top View of Tape Transport. OPERATING INSTRUCTIONS Hook-Up Procedures: (1660-D) 1. The outputs, high and low level are cathode follower. low impedance preamp outputs. The instructions of the external power amplifier and or tuner should be followed. However as a rough guide the following may be helpful. Interconnecl . . High l-evel Output . to . Tube amplifier. a. High level input b. Auxillary input c. Preamp input d. Tuner input Low Level Output . to . Transistor amplifier. a. Input b. Preamp input c. Tuner input d. Auxiliary input Rad/Phono Input . to . Tuner Output to . Amplifier Tape Out to . Amplifier Preamp Out to . . Phono. Ceramic Cartridge to . Phono. Preamp Out to . parallel with TV speakers to . parallel with Radio speakers Threading the Tape: 1. Place a full reel of tape on feed spindle. Place an empty reel on t.akeup spindle. Secure reels in place with rubber reel holders provided. 2. Unwind aboul 14 inches of tape from feed red. Hold a section of tap! taut and thread per photo. Make sure !.ape pulls automatic tape shutoff switch arm u p to On po.ition. 3. TnsPrt fret end of tape into one of the radial slots in hub of takeup reel. Hold tape end in place and turn reel several turns counterclockwise to secure tape to the reel. To Make a Stereo Recording: 1. Connect recorder to 110-125 volt 60 cycle power source with power cord provided. Turn power switch to Power On. 2. Thread the t.ape. Set Index Counter to zero. 3. Connect signal source to proper input. a. If microphones are used connect them to microphone jacks. Level will be controlled by the volume controls. Fig. 3. Bottom View of Tape Transport. b. If a phono or radio source is used connect their out-puts to the respective channel Phono-Radio input jacks. Level will be controlled by the volume controls. 4. Push Pause Lever to Up position. !i. Hold record switches depressed. 6. Tum start/ stop control to Start posit1on. This hold; the record switches down in record mode. 7. Start signal source to set recording level. VU Meters should read -3 to - 7 on the average. 8. Release the Pause Lever (down) to start tape. Tracks 1 and 3 are now being recorded. 9. When recording is completed, or when the end of the reel of tape is reached, return start/stop control to Stop position. Record switches are automaticaUy re-leased to return to play position. 10. To record tracks 2 and 4, remove full reel from take-up spindle. turn over and place on supply spindle. Proceed as in steps 2 - 9. To Play a Stereo Recording: 1. Connect recorder to proper power source with power cord provided. Turn power switch to Power On. 2. Thread the tape. Set Index Counter to zero. 3. Locate desired starting point by using Fast Forward-Rewind knob while observing Index Counter. 4. Turn Start-Stop knob to Start position. Adjust volume for each channel. Both tracks of a 2-track stereo tape or tracks 1 and 3 of a 4-track stereo tape will now be played. 5. Tape may be advanced rapidly or rewound, after Start-Stop knob is placed in stop position, by using Fast Forward-Rewind knob. 6. To play tracks 2 and 4 of a 4-track stereo recording after tracks 1 and 3 have been completed, do not rewind tape. Remove full ree from takeup spindle, turn it over. and place on feed spindle. Proceed as in Steps 2-5 above. Monaural Recording and Playback: Proceed as indicated for stereo operation but use only jacks. controls and switches for one channel. Volume con-trols for the unused channel should be set at zero. To record four monaural tracks. use left channel first. recording track 1. Reverse tape by removing full reel from Lakeup spindle, turning it over. and placing it on the feed spindle. Continue to use left channel while recording track 4. Reverse tape and use right channel to record track 3. Rever.se tape again and continue to use right channel in order to record track 2. To play back four monaural tracks. use the same sequence of tape sides and recorder channels as when recording. 5 6 SOUND-WITH-SOUND RECORDING This is a procedure by which you may record yam favorite orchestra on one channel, and then play or sing with the re-cording in such a manner as to make the playback sound as though you were right there . with the orchestra. Or it may be used for language study. with the teachers voice on one channel and your responses which may be erased and re-re corded as often as desired) on the other channel. ROBERTS Language Laboratory Tapes. available from your Roberts dealer, have tne instrucors voice pre-recorded in this manner in four differe.nt languages. PROCEDURE: 1. Make a master recording on Track 1. using Left chrumel only. Turn Right channel volun1e controls to zero and fol low procedure m1der To Make a Stereo Recording, using Left channel only. 2. Rewind tape. 3. Record on Track 3, using Right channel only while listening to Track 1. 4. Rewind t.ape. 5. Play back recording, as in stereo play. Master recording will be heard on Left channel and added recording will be heard on the Right channel. 6. Track 3 may be erased and rerecorded without disturbing master track by repeating Steps 2 through 4. SOUND-ON-SOUND RECORDING (1660D ONLY) 1. Make original recording on Track 1 using Left channel only. Turn Right channel volume control to zero and follow procedure under, To Make a Stereo Recording. 2. Rewind tape to beginning of original recording. 3. Set Channel Transfer Switch io L toR position. 4. Push Pause Lever up to Stop position. 5. Hold Righi Record Switch depressed and turn Start-Sto p knob to Start position. 6. Connect Right challllel microphone. Apply sig11al to microphone and adjust the Right channel volume control for ap-proximately half the normal recording level reading on the Right channel VU Meter. 7. DO N01 READJUST THE RIGHT CHANNEL VOLUME CONTROL AFTER PRESETTING FOR THE MIC-ROPHONE RECORDING LEVEL. (V:! Jormal) 8. Releae Pau:e Lever and make a tdal recording of the Left cbael trSllSfer and the Right channel microphone added. 9. Adjust the Left channel volume control only, while watching the Right channel VU Meter reading. The Right chan-nel VU Meter should be reading full normal. Half of the reading will be the Left cbrumel transfer ru1d the other half. the Right channel microphone. 10. Rewind the tape. play the trial recording. If the test run was satisfactory. proceed with the final recording by re-peating Steps 2 !hrcugh 9. 11. Playback recording. Sound-On-Sound recording is on Track 3 (Right channel) so volume controls for Left channel should be set to zero. (NOTE: The original Track l recording of the Left amplifier is still intact at this point, so Steps 2 through 9 may be repeated if the final recording was not satisfactory.) 12. The aboe process may be repeated, using Track 3 as the original recording and add more material to it for a rnul-tirle recording. In this case the Channel Transfer Switch should be set at R to L position, and the Left channel microphone input will be used. ASSEMBLY -DISASSEMBLY Assembly (mounting): (1660-D) 1. Check for dearance, (deck & prean1ps, reels, ease of op-eration. etc.). Transfer cutout pattern from template to panel. Cut out panel opening. 2. Remove side angle bra:kets rom metal cage. 3. Install unit into panel cutout. 4. Reinstall side angle brackets onto rne.tal cage, and press up against underside of panel. 5. If panel is .1f2 or mar thick, fasten angle brackets from underside with wood screws, into panel. 6. If panel is less than 1/2 thick use fancy headed bolts and nuts clear through panel. For Access to Top of Tape Deck: l. Remove Start-Stop Jmob and Fast Forward-Rewind knob. 2. Remove 3 transport deck mounting screws, capstan bush-ing storage rost. 3. Pry out pinc:hwheel cap. take out pinchwheel mounting screw. and lift oU pinchwheel. 4. Remove bcth reel tables after taking CJut reel table screws. Note humber of fibre spacers under reel tables as they are removed. 5. Lift off transport deck panel. MAINTENANCE INSTRUCTIONS LUBRICATION Lubricate the following parts every thee months when the ecorder is subjected to heavy usage. every six months under moderate usage, and once a year unde conditions of occasiona1 use. l. Feed and take-up spindle shafts with two drops of light machine oil on each shaft. 2. Rewind idler bearing and wind idler bearing. with two drops of Light machine oil on each bearing. 3. Apply a liberal amount of light grease to each roller and on all levers and cams. 4. SatuTate the felt washer in the retaining cup of the drive capstan with light machine oil. Caution: Do not allow grease or oil to remain on any of the drive surfaces, or on plastic surfaces or any part touch-ing the tape. CLEANING The capstan, pinchwbeel, tape guides, and .reco.rd/ play head and erase head accumulate a tape oxide coating as the tape passes these parts. Clean these parts periodically with a soft cotton swab dipped in alcohol. MECHANICAL ADJUSTMENTS 1. Record-Play Head Height-Loosen the two mounting nuts a