Ampro-Model745-tape-sm 电路图 维修手册.pdf

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1、PnoToFACT* FolJrt AMPRO MODET 745 Coreer L o o L o o!, CP E tr1 =x J ut o o = =o I llt F xi gt! av .iO o ! o o T GENERAL INFORMATION The Ampro Model 745 is designed to record and play back two tracks of material on standard width recording tape, which doubles the playing time of a reel of tape with

2、no loss of frequency response or quality. Recordings can be made from a radio, television receiver or phonograph, in addition to those made directly from the microphone. Recordings can be played backthroughthe self-contained speaker or an external speaker through use of the Speaker Jack. The Model74

3、5 has two tape speeds, 3 3/ 4 and ? I/2 per second. Using both tracks of the tape the recording time is as follows. Size Reel 3 3/ 4 Speed 5 reel (600 ft. ) I hour 7 reel (1200 ft. ) 2 hours 7 I/ 2 Speed /2 hour I hour This unit is designed to operate on 60 cycie, 115 volt, AC supply only. Before co

4、nnecting to your line supply, be absolutely certain that it agrees with the above specifications. Manufactured by: Ampro Corporation 1345 Diversey Parkway Chicago 14, Illinois fhis molerial compiled ond published by 5AM5 Remove patch cord after recording is com- sition. pleted. To Use Second Track-

5、=o I tlt F xi l,l! av fio o a o o rll 1. Move Play or Record-Stop-Rewind lever to the Stop position when all the tape has wound onto the take-up reel. 2. Remove reel containing tape and place on left-hand supply spindle. 3. Place empty reel on right-hand take-up spindle. 4. Thread tape as previously

6、 described. To Play Recordings- 1. Turn on unit with Volume control knob. 2. Thread tape as described under ilThreading The Tape. 3. Set the speed change knob (tA)to the speed at which the recording was made. 4. Turn Play-Stop-Rewind lever to play. 5. Adjust Volumef and Toneil controls to de- 2. Hol

7、d down Fast Forward Buttont (6) on top of right reel spindte (?). 3. Release when tape has advanced to location on the tape you wish to hear or record. To Rewind- 1. Before rewinding, return Play-Record con- trol to Play position. 2. Turn Play-Rewind lever to rewindr. Re- wind tape to beginning of y

8、our recording and return lever to stop. To Edit And Splice Tape- NOTE: Since it is impossible to edit and splice one track without affecting the other, recordings which are to be edited should be limited to one track only. 1. The tape maybe editedby cutting out unwanted portions, or joining selectio

9、ns into another sequence Announcements may be inserted between selections, etc. Unused sections of tape can be spliced together for re-use. Page 3 RadioFans.CN 收音机爱 好者资料库 2. Forbestresults, cuttape at a slight diagonal, join ends together with splicing tape on the glossy side and trim off any excess

10、ive width. E rasing Recorded Material- When the Play-Record knob (3) is in the Record position, the erase head is automatically in operation, erasing any previous recording before a new one is made. You may erase material no longer needed, without recording, by moving the Play-Record knob (3) to Rec

11、ord on turning the Volume control knob to the minimum volume position just before the record- er shuts off. Onetrack is erased at a time, To erase the second track, reverse the reels and repeat the above operation. To Use Recorder As A Public Address System- Plug microphone cord into IMic. or Phonoi

12、l re- ceptacle. Turn Play-Record controlto Iphono-record position. Be sure microphone is far enough away from speaker to avoid feedback squeal. Volume may be ad- justed with Volume eontrol. Mikeand/or radio-phono can be simultaneously used for blending of special effects in public address use with A

13、mpro Dual - Input Mixer, No. 133. ELECTRICAL ADJUSTMENTS Erase Head Adjustment- I, Loosen screws located on the left side of erase head and raise or lower head and tilt head as required in order to obtain minimum output. 2. Then loosen screw (32A) and rotate position- ing block for minimum output. 3

14、. Tighten screw (32A) and rotate positioning block for minimum output. 4, Checkfor oppositetrackerasure if excessive, head is set too low. Record Head Adjustment- The record head is mounted on a pivoted plate which is held in place by two filister head screws (32B) located at opposite corners of the

15、 plate. Tight- ening or loosening the screw on the left (viewed from operating position) rocks the pivoted plate thereby changing the angular relationship between the gap and thetapeand increasing or decreasing the compression oI the spring located under the head of the opposite mounting screw. In o

16、rder to make an adjustment, threadtherecorder with pre-recorded 1 mil alignment tape or a good recorded tape on the machine. Connect an output meter across the terminals of the elliptical speaker. Switch recorder to play po- sition and set the volume control to the 12 oclock po- sition. Rotate the s

17、crew which secures the left side of the plate in order to obtain maximum output from the pre-recorded material. Make a rough adjustment at a tape velocityof 3. ?5 inches per second the switch to ?.50 inches per second for final adjustment. NOTE: Watch out for a false peak you may find 3 peaks - be s

18、ure to adjust for strongest peak. Page 4 Erase Current- Disconnect the ground lead at the erase head terminal and insert a 10 ohm non-inductive resistor. Qonnect a VTVM across the resistor. Switch to record and note voltage. Correct voltage will be ap- proximately 0,4-0. 5 volts indicating an erase

19、current of approximately 40-50 ma. Bias Current- Disconnect lead from record head. Insert 100 ohm non-inductive resistor between red lead and re- cord head terminal and connect VTVM acrossl00 ohm resistor. Turnvolume control to low volume position. Switchtorecord and measure voltage across resistor.

20、 Voltage shouldbe 0.40 - 0,45 volts which is equiva- lent to a current of 0.40 - 0.45 ma. If bias is not within these limits adjust slug in oscillator coil to obtain correct current. MECHANICAL ADJUSTMENTS Erase Interlock Cam Adjustment- l. Loosen set screw slightly so that cam (34) can be turned on

21、 control shajt. 2. Turn shaft to maximum clockwise tPlayt position. Rotate cam so that flat surface is parallel to edge of interlock spring (35). 3. Press in on interlock spring, then turn con- trol shaft in order to expose setscrew. Tighten set- screws. Rewind-Play Or Record Cam (29) Adjustment- 1.

22、 Turn control shaJt to maximum counter- clockwise (Play or Record) position. 2. Loosen setscrews in cam. Rotate cam so thatcamflatis parallel to flat surface of pad actuating arm (24). 3. Raise or lower cam (29) as required in order to locate top face of cam in the same plane as top of arm (24). Tig

23、hten setscrews. 4. Place light film of Lubriplate on surface of cam which comes in contact with arm (24). Disassembly Instructions- 1. Take outthe four Phillips filister head screws located at the corners of the panel (5). Loosenthetwo allen setscrews in the Rewind-Play or Recordl knob (3) and remov

24、e the knob. Puli off the other three knobs (2). Lift off the control panel (5). 2. Removethreephillipsoval head screws which hold speed change control cover (l) in place and lift off cover. 3. Take out ten phillips oval head wood screws which hold metal panels to case. 4. Loosen cable clamp which ho

25、lds line cord to back of carrying case. Standrecorder on end and pull mechanism out of case. Takeup Brake Adjustment- Place Rewind-Play or Recordtt knob in Playtt t- 0 Figure position. Loosen locknut on adjustment screw (19A) andturn screwto provide a clearance of I/ 64 between shoe (19) and tire (8

26、). Tighten locknut. Feed Spindle Brake Adjustment- Place tRewind-Play or Record knob (2) in Play position. Loosen double nuts at end of brake rod (48). Adjust nuts to provide a clearance of L/ 32 between shoe (67) and tire (?0). Rotate feed spindle and check to make sure that eccentricity, if presen

27、t, does not reduce clearance below minimum value of L/ 32. Tighten locking nut. Instant Stop Link- Set inner nut of link (14) L 5/ 32* from end of link (14). Set outer nut flush with end of tink. Rewind Adjustment- Place Rewind-P1ay or Recordil knob in ftPlaytt position. Loosen double nuts at end of

28、 pushrod (30). Adjust nuts to provide a clearance of L/ 64 between rewind drive belt (ab) and knurled section of drum (69). NOTE: If rewind does not function properly, and the rewind belt (45) is not damaged, the trouble is probably due to excessive take-up tension. Takeup Adjustment 1. Cement 8-10

29、of tape or string to the hub of a ? reel. Place reel on takeup spindle and hook a spring balance scale (0-8 oz. or 0-16 oz) to the loose end of the tape or spring. Switch recorder to trplayrr 3 measure the takeup tension-correct tension should be l/2toLoz. 2. lf. takeup tensions are incorrect, remov

30、e recorder from case. Loosen two setscrews which hold the intermediate drive putley (47) to takeup drive spindle and pull out spindle assembly. 3. Grasp the spindle by the shank (9), hold spindle in a vertical position with the reel drive pins on top. Hook the spring balance scale to one of the reel

31、 drive pins and pull along a line as a right angle to a line thru the center of the spindle post and pin. The breakawaytensionrequired to rotate the spindle should be 3 to 5 oz. In order to adjust tre tension, invert the spindle and insert the ends of the jaws of a pair of longnose pliers into the t

32、wo holes in the clutch pressure plate (12). Turn the plate to the right to increase the tension. NOTE: Thisadjustment is sensitive when making ad- justment, do not turn the plate more than the width of one of the holes between tests. TROUBLES Whining Or Scrapping Noise- 1. The recorder is shifted in

33、 the case, the bottom end of the motor shaft rubs against the guide sleeve in the bottom cover and produces the noise. 2. Reposition the mechanism in the case and tightenthe retaining screws. If theholes in the support blocks are damaged, the best way to make a permanent repairisto inject plastic wo

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43、o :d -ir *6 6 6 () z ts 4 a ii 6-) i ri5 n. 3 i ; q: FLE PAGE II Description 7 8 I 10 1l L2 l3 I 15 16 L7 18 19 20 2t 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 75636 -2 74612 ?4631 ?4614 -1 74206 Speed Change Cover Speed Change Knob Control Knob Record - Play - Stop-Rewind Rear Plate Front Escutc

44、heon Safety Button Fast Forward Button Take-Up Spindle O Ring Take-Up Drive Hub Drum Fast Forward Actuating Shaft Felt Clutch Adjusting Disc Pivot Arm Pull Rod Pinch Roller Assy. Instant Stop Arm Spring Instant Stop Arm Instant Stop Arm Pivot Take-Up Brake Arm Take-Up Brake Arm Spring Take-Up Mounti

45、ng Plate Baseplate Screw Pad Actuating Arm Head Pressure Pads Pad Actuating Arm Spring Pad Actuating Arm Pivot Pinch Roller Spring Play-Record Cam Push Rod Recording Head Erase Head Escutcheon Support Erase Interlock Cam Interlock Spring Rewind Driver Arm Rewind Spindle Rewind Mountins Plate 39 40 4

46、T 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 5? 58 59 60 61 62 63 64 65 66 6? 68 69 70 7I 72 73 74 75 76 77 L PARTS 16403 Capstan Bearing & Housing Instant Stop Bel1 Crank & Link Spring Spring Rewind Brake Actuating Lever Rewind Drive Belt Forward Drive Belt Intermediate Reel Drive Pulley Rewind B

47、rake Push Rod Cil Retainer Flywheel Support Bracket Vertical Position Screw Flywheel & Capstan Drive Belt Belt Shifter Motor Pulley Brake Release Arm Screw Washer Motor Mounting Shoeks Rubber Washer Spacer Motor Mounting Bracket Motor Mounting Plate Motor Fan Spring Supply Spindle Brake Brake Spring Rewind Brake Drum OtRing Rewind Pulley IdIer Pulley Idler Arm IdIer Spring Speed Shifter Stop Speed Change Lever Steel Ball Capstan Support Page 12 Figure 5