Oak Mfg. Co. 6666 Schematic

Oak Mfg. Co. 6666

Get a print!

Product Information:
Manufacturer:Oak Mfg. Co.

Schematics Content

Page 1:

support upward to permit easy record removal.
b. Lift played records from turntable.

Manual Operation
1. Raise hinged 10 inch record support into vertical position.
2. Place record over spindle onto the turn table.
3. Push starting switch to "ON" position.
4. Push reject button into manual playing position,
5. Place pickup arm at beginning of record to start playing operation.
6. When through playing place pickup arm on pickup arm rest and push starting switch to "OFF" position.

Cycle of Operation of Correctly Adjusted Mechanism
1. With pickup arm (46) on pickup am rest (79) and center post dogs (81) and 10" record support down, place stack of 10" records on center post (66) and 10 " record support (57) ears. See Fig. (1).
2. Place balance arm (56) on records. See Fig (1)
3. Push motor switch (24) to "ON" position. See Fig. (1).
4. Pull reject button (80) to reject position and release. See Fig. (1).
a. Drops 1st record.
b. Places pickup arm (46) in playing position.
5. Play 1st record.
6. Needle approaches center grooves carrying ratchet arm (2) towards adjusting stop lever (8). See Fig. (2).
7. Contact of ratchet arm (2) and adjusting stop lever (8) disengages jaws of adjusting stop lever (8) & kickoff lever arm
(17). (See Fig. (2).
8. Jaws release kickoff lever arm (17) assembly, rotating it into path of kickoff spring (15) which rotates on turntable
(11). See Fig. (2).
9. Contact of kickoff spring (is) & kickoff lever. (16) rotates kickoff lever arm (17) assembly into locked position with locking lever (21). See Fig. (2).
10. Further movement of turntable (11) causes kickoff lever (16) to disengage dropping lever (18). See Fig. (2).
11. Lead roller assembly Fig. (3) drops into turntable spiral (85). See Fig. (4).
12. Disengagement of kickoff spring (15) &
kickoff lever (16) rotates kickoff lever to original position. See Fig. (2, 5).
13. Swing arm (26) assembly Fig. (2) is driven through first half of cycle by turntable spiral (85). See Fig. (4).
a. Adjusting plunger pin (50), riding on swing arm (26) cam, elevates pickup arm (46). See Fig. (6).
b. Assembly in Fig. (7) is set by arm cam (40) so as to position ratchet arm (2) Fig. (9) on return stroke for proper set down of needle.
c. Ratchet arm friction springs (25) engage ratchet arm (2) rotating pickup arm (46) to clearance position. See Fig. (2).





d. Ejector idler lever (34) driven by swing arm (26) Fig. (2) actuate rec or ejector assembly Fig (8). Dropping next record from stack.
e. Swing arm (26) ear, cams locking lever (21) resetting kickoff lever assembly (17). See Fig. (2).
f. Cammed dropping lever (32) Fig. (2) releases return roller assembly Fig. (3) dropping it into turntable spiral (85) Fig. (4).
g. Inner spiral cam (63) Fig. (4) raises lead roller assembly Fig. (3) permitting dropping lever (18) to rotate to setting position. See Fig. (2).
14. Swing arm (26) assembly Fig. (2) is driven through second half of cycle by turn table spiral (85) Fig. (4).
a. Pickup arm (46) is positioned for set down driven by engaged ratchet am friction springs (25) and ratchet arm (2) and located by interference of ratchet arm lever (29). See Fig. (2; 9)
b. Record ejector assembly Fig. (8) is reset to original position.
c. Swing arm (26) ear releases locking lever (21) allowing it to assume original position. See Fig. (2).
d. Operation of brake spring (22) prevents acceleration of swing arm (26) at completion of cycle. Gentle set down of pickup arm (46) is so effected. See Fig. (2).
e. Adjusting plunger pin (50) riding on swing arm (26) cam causes pickup arm (46) to descend to playing position. See Fig. (6).
f. Assembly in Fig. (7) is released by arm cam (40) resetting ratchet amm lever (29) in clearance position as shown in Fig. (2).
g. Inner spiral cam (63) Fig. (4) raises return roller assembly Fig. (3). Rotation of cammed dropping lever (32) Fig. (2) provides clearance between inner spiral cam and return roller assembly. This completes the change cycle.


15. Tripping of mechanism by. eccentric grooves in center of record.
a. As record is being played ratchet dog (5) and ratchet lever (6) make contact. See Fig. (2).
b. Eccentric grooves in record produce oscillation of ratchet arm (2) and ratchet dog (5). See Fig. (2).
c. Oscillation of ratchet dog (5) across ratchet lever (6) lengthens ratchet arm (2) assembly, rotating ratchet lever (6). See Fig. (2).
d. Rotating ratchet lever (6), rotates adjusting stop lever (8) disengaging jaws of adjusting stop lever (8) and kickoff lever arm (17). See Fig. (2),
16. For remainder of cycle see parts 8 through 14 above,

Page 2:


1. Check power supply to motor. Motor operates at 115 volts 60 cycle alternating current unless otherwise specified on motor.
2. Remove turntable (11), move motor idler pulley (82) away from motor shaft (84) and check for motor performance Fig. (1).
3. Check for freedom of motion of motor idler pulley (82) and motor spring (83) tension on same. Fig. (1).
4. Check for grease or foreign matter on motor idler pulley (82) or turntable (11) rim which may cause slippage. Fig. (1).
5. Check for worn motor idler pulley (82) tire. Fig. (1).
6. Check for grease or foreign matter in bearing for turntable collar (62) and mechanism plate center stud. (64). Fig. (4).
7. Check for absence of adjusting plunger pin (50). Fig. (6).
8. Adjusting plunger pin (50) incorrect length. Place pickup arm (46) in upright position and remove adjusting plunger pin (50) with acorn nut. Adjust overall length of pin assembly to give approximately 74 " clearance between top of pickup arm and bottom record of stack of unplayed records when unit is in change cycle. Fig. (6).

9. Trip mechanism and rotate turntable (11) by hand until swing arm (26) completes half of its cycle. Loosen screw in cam trip bracket (30) and rotate bracket until there is. 012" to. 014" clearance between leading edge of car dropping lever (32) all in Fig. (2) and bearing pin shoulder nut (73) Fig. (3) of dropping roller. Return swing arm to original position. Retighten screw. Re check this setting by tripping mechanism and rotating turntable by hand observing whether return roller assembly Fig. (3) enters turntable spiral (85) Fig. (4) at formed flat on turntable spiral at completion of half of swing arm cycle.
10. Back up turntable (11) turning it counter clockwise slightly and remove turntable. Push both rollers (71) of swing arm (26) down and push rollers (71) towards reject button (80) to the end of their travel. Replace turntable and rotate by hand for at least one revolution. Fig. (1).

11. Check drop lever torsion spring (20) and cammed dropping lever torsion spring (33) for adequate tension, Fig. (2).
12. Check for worn or frayed rubber on drop ping lever (18), replace if necessary. Grease rubber sleeve after installation. Fig. (2). This sleeve, above (73) Fig. 3, may be eliminated entirely for better operation.
13. Check for defective ratchet arm friction springs (25). Fig. (2). If found to be loose or weak, return changer to factory for adjustment.
14. Check ratchet arm (2) for tight engagement with pickup arm swing post (47). Fig. (2,6).
15. Trip mechanism and rotate turntable (11) by hand until swing arm (26) completes. half of its cycle. Loosen lock nut on ejector idler lever (34) Fig. (2). Adjust screw until finger (54) protrudes outside of ejector box (53) 15/64". See Fig. (10). Tighten lock nut.
16. Check proper height from ejector box (53) cars to maximum rise of finger (54) top is. 085" to. 095". See Fig. (11). File to give proper dimension.
17. Check 10" record support (57) Fig. (8) for height differential between ears of 10" record support (57) and top of pusher pin (58). Pin should engage record by. 080" to. 090". Bend to suit.
18. Put a 10" record on turntable (11), loosen screw on ratchet arm (2) and place pickup needle approximately 4" from outside edge of record. Rotate by hand ratchet arm lever (29) and ratchet arm (2) to position shown on Fig. (9) and retighten screw. This setting will automatically set needle down correctly for 12" records also.
19. Move swing arm (26) away from reject button (80) for about 1" of its travel. Check movement of ratchet arm lever (29) which should assume position shown on Fig. (7 or 9) when 10" record support (57) is in down position. Hampered movement may be caused by defective ratchet amm extension spring (38) or excess friction.






Page 3:

20. Remove brake spring (22) and inspect for possible fracture. Replace fractured spring, use two springs if necessary. Fig. (2).
21. Check for defective cam lever extension spring (27) and possible excess friction in parts. Fig. (7).
22. Check for adequate freedom of pickup cartridge wire.
23. Pickup arm (46) should weigh 1/4 oz. when scale is applied at set screw. To adjust weight rotate ratchet for pickup arm (45) so to decrease or increase tension on pickup arm balance spring (44). See Fig. (6).
24. Needle may be worn beyond use.
25. Check to see that changer is level.
26. Check freedom of movement of adjusting stop lever (8) Fig. (2 or 5).
27. Check for presence of all springs See Fig. (2),
28. Tripping levers may assume position shown in Fig. (5). Reset levers by pulling reject button (80). If occurrence is frequent observe for extreme wear of nib at point where kickoff spring (15) contacts kickoff lever (16). Fig. (2). Replace kick off lever arm (17) assembly and remove 1/32" of mechanism plate (1) increasing size of hole which limits outward travel of kickoff lever arm (17). Remove material from farthest edge from center post (66) allowing greater movement of kickoff lever arm (17) assembly.
29. Set pickup needle at a point 176 " from center of record, loosen lock nut and turn screw on adjusting stop lever (8) Fig. (2) until kickoff lever arm (17) releases allowing 1/64" clearance between jaws of adjusting stop lever (8) and kickoff lever arm (17). See Fig. (12). Tighten lock nut.
30. Check for distorted or fractured kickoff spring (15) Fig. (4).
31. Records not manufactured under R.M.A. specifications may not trip changer,

32. Bend the ear on the adjusting stop lever (8) slightly towards heel of ratchet lever (6), to produce increased interference of ratchet dog (5) and teeth of ratchet lever (6). Fig. (2),


33. Apply force with pliers to bend ratchet arm stop bracket (4) away from reject button (80), until pickup arm (46) will rotate to a position allowing 12 " record to drop without interference. Fig. (2).
34. Check cabinet cutout for adequate clearance of ratchet arm (2). Fig. (2).
35. Check for worn roller tires (72). Fig. (3).
36. Remove friction spring washer (62) and replace with. 010 " friction spring washer (62) or eliminate if necessary. Fig. (4).
37. With starting switch (24) " OFF trip mechanism and rotate turntable (11) by hand. Check that lead roller assembly and return roller assembly Fig. (3) drops into turntable spiral (85) Fig. (4) without touching flange of turntable spiral. Check for foreign matter which would prevent roller assembly from dropping full extent of travel,
38. Lubricate bearing for turntable collar (69). Fig. (4). Use very light machine oil, 3 in 1 or equivalent.
39. Check for foreign matter between turntable (11) and mechanism plate (1). Fig. (1).
40. Defective records.
41. Defective cartridge and amplifier circuit.

When ordering parts for Model # 10700 Record Changer, specify changer serial number, item number, part number, and description. When ordering motor parts be sure to specify the mo tor number stamped on each motor. Order special rivets from respective part numbers.

Page 4:

Servicing Procedure
1. The following procedure, when followed, will provide the service man with a method of repair which will save him much unnecessary time and effort. Start servicing the changer by performing adjustment # 10. This will assure the service man that the changer is in the correct position for proper operation.
2. With pickup arm (46) on pickup arm rest (79) and center post dogs (81) down, place stack of 12 new 10" records on center post (66) and 10" record support (5 (). ears. See Fig. (1).
3. Push starting switch (24) to "ON" position. See Fig. (1).
4. Pull reject button (80) Fig. (1) to reject position and release, ob serving changer action for any of following possible difficulties. Difficulties encountered may be corrected by following the respective procedure and adjustments indicated.

a. Turntable does not rotate,
b. Pickup am does not rise.
c. Pickup arm rises but does not rotate into playing position and remains suspended in air. Turntable continues to turn, Click heard on each revolution.
d. Pickup arm rises but does not rotate into playing position and remains suspended in air. Turntable comes to a dead stop cannot be turned by hand.
e. Pickup arm rises but does not rotate into playing position,
then sets to rest on pickup arm rest.
f. Bottom record does not drop off of supporting ears of 10" record support (57) and center post (66) Fig. (1).
g. Pickup am hits bottom record of not played records.
h. Needle does not set down correctly for 10" or 12" records.
i. Pickup arm drops fast when setting needle on record.
j. Pickup arm needle does not track in groove.
k. Pickup arm needle jumps out of recording grooves and doesn't trip mechanism.

Procedure & Adjustments
l. Mechanism does not trip at end of record.
m. Eccentric groove on 10 * records does not trip mechanism.
n. Changer does not play entire record.
o. Pickup arm does not lift high enough to clear stack of 12 10" records on turntable.

5. With pickup am (46) on pickup art rest (79) and center post dogs (81) down, place stock of 10 new 12" records on center post (66) and 12" record support ears of ejector box (53). Fig. (1).

6. Push starting switch (24) to "ON" position. See Fig. (1).

7. Pull reject button (80) Fig. (1) to reject position and release, ob serving changer action for any of following possible difficulties.
a. Bottom record does not drop off of supporting ears of ejector box (53) and center post (66).
b. 12" record hits pickup arm when record drops to playing position.
c. Eccentric groove on 12" records does not trip mechanism.

8. Play any record. Observe and listen for noises which not not seriously hamper operation of changer but detract from performance of changer.
a. Click is encountered on each revolution of turntable during playing cycle.
b. Apparent growl or scroll noise caused by improper operation of roller (71) Fig. (3) on turntable spiral (85) Fig. (4) during change cycle.
c. Extreme variation of turntable speed.
d. Distortion of tone quality of recording.
e. Excessive wear of records.
f. Turntable vibrates or chatters.

Page 5:


This changer automatically plays ten 12" records or twelve 10" records. Service information contained in this bulletin covers the operation, care, and adjustments that may be necessary if the mechanism fails to operate properly.

The motor shaft presses against its idler wheel which turns the turnable (7103 or 7107) from the inside rim. The turntable rests on a pin through the turntable shaft 6655 and causes the turntable shaft to turn. The pinion 4246 at the base of the turntable shaft turns in a notch in the drive cam 4207 while records are playing. When the pickup arm 4283 reaches the inside groove of a record the bracket 6697 on the pickup crank 6694 presses against the trip screw 7555 which is mounted in the pawl latch assembly 7809. The opposite end of the pawl latch assembly releases the starting pawl 6643 allowing the starting pawl to engage the pinion. This starts the drive cam 4207 and the change mechanism.
As the cam begins to turn, the lift pin 6876 is forced upward by the raised portion of the cam. This lifts the tone arm off the record. The cam follower 6695 then rides its groove on the cam and swings the tone arm outward. During this outward swing the indexing pin 6862 slides off the index stop 6856 and is pushed upward by the indexing pin spring 4272. While the tone arm is all the way out, the starting pawl 6643 is cocked into position by the bracket 6697 on the pickup crank 6694.
The cam follower swings the tone arm in until the index pin 6862 contacts the index pin stop thus getting the proper needle drop position,

Page 6:


While the cam is turning the eccentric 6645 turns the changer blades thru the action of the eccentric arm 7144 and the tie bar 7562 which connects the changer shafts 4229 and 4232 together,
When the cam again comes to rest it is held in position by the cam stop lever 6659 and cam stop roller 6660.

In manual operation the manual link 6668 holds the starting pawl 6643 in the cocked position at all times.

The reject link 6667 releases the pawl latch assembly 7809 allowing the starting pawl 6643 to engage the pinion 4246 and start the change cycle.

These adjustments are made correctly at the factory and ordinarily need never be altered. Should it become necessary to readjust, due to accident or tampering, proceed as follows: A

. Adjusting The Needle Landing Position
The needle drop adjusting screw 6715 is readily accessible from the top of the changer. To adjust, loosen the nut and turn the screw with a screw driver. Maximum adjustment is obtained from one complete turn of the screw-any more than one turn merely repeats itself. At the factory the needle drop is adjusted to 413 inches from center for a ten inch record and 511 inches from center for a twelve inch record. Both landing positions are governed by

Page 7:


the the same screw so adjusting for one or the other should be sufficient. When completed, tighten locking nut.
If the landing position is out of range for the adjusting screw, the clamp 6858 may have loosened. With the drive cam 4207 in the rest position, move the cam follower 6695 in towards center as far as possible. Then move the tone arm in approximately 14 inches from center and tighten the clamp 6858. For fine adjustment, readjust the needle drop adjustment screw.
If the tone arm is bent it may require straightening. After straightening, run the changer through a change cycle manually and make sure the tone arm has proper height. (For height adjustment see paragraph B.)

B. Adjusting the Tone Arm Height
The needle should clear the turntable by 1'4 inches when at maximum height during change cycle. Adjustments can be made by turning the lift adjusting screw 4245. Before the power switch is turned on the changer should be run through its cycle manually to make sure that the tone arm passes underneath the lower change blade and does not jam.
If this adjustment is correct and the tone arm doesn't drop low enough to play the bottom record, inspect the main cam and see that the tone arm lift pin 6876 is all the way down in the hollow on the cam. If not, inspect the cam stop roller 6660 and see that it is in the proper position. Grasping the eccentric arm 7144 and pulling downward may help if the trouble is due to binding.

Page 8:


C. Adjusting the Position of Trip The change mechanism should start when the tone arm is approximately 111 inches from center. The trip occurs when the tone arm lever presses against the trip screw 7555 on the pawl latch assembly 7809. This screw can be adjusted to change the trip position.

D. Adjusting the Record Drop Both lower change blades are adjusted to drop a record simultaneously. A loosened driving crank 4224 would allow a record to drop on one side be fore the other. To reset, turn the turntable manually until the record is just about to drop, loosen the the driving crank4224 and adjust change blades so they are even. Then tighten clamp.

E. Adjusting Needle Pressure The needle pressure can be adjusted by turning the pickup spring adjusting washer 4308-1 which changes the pressure of the pickup spring 7818. This adjustment is made for the particular cartridge being used and adjustment may be advisable if a substitute cartridge is used.

Squeaks sometimes occur due to friction between the unplayed stack of records and the spindle. This may be eliminated by applying a thin coat of wax or vaseline to the spindle at the point of contact.
Check the oil wick 4228 on the main cam, perhaps it needs oil. If the wick appears dirty or gummy it

Page 9:


should be removed, thoroughly cleaned, and re placed. WEAK OR NO OUTPUT Check the pickup lead from the pickup to the amplifier.
If the amplifier is O.K. replace crystal pickup.

No power applied to the changer.
Faulty switch 7478-4. Burned out motor winding. (See replacing motor.) Idler wheel spring disconnected. Foreign material jamming motor armature.
If in change cycle cam jammed or tie bar 7562 rubbing against the sub frame assembly 7806.

Improper voltage or frequency. Drag on turntable or motor.
Motor or turntable bearings binding.

FAILS TO TRIP Starting pawl spring disconnected. Trip screw missing or set improper. Bent starting pawl or pawl latch. Dirt binding starting pawl or pawl latch rivets. Tone arm lever loosened. (See adjustment A.)
The pickup lead wire which emerges from the rear of the tone arm and goes down through the metal base is so placed that it will not hinder the movement of the tone arm. This lead should be free at all times, do not attempt to push excess wire through the base.

Page 10:


Warped records are the most common cause for jamming or chipping records. Should the change blades chip fiat records they should be bent to have a, 06" clearance between them.

This is most likely due to the driving crank 4224 having loosened. For resetting instructions see Adjustment D. REPLACING A MOTOR Remove the turntable by lifting and giving the spindle a sharp tap to release it. Remove the power switch by taking out the two Phillips screws, Remove the switch cover and disconnect the motor wires. Disconnect the motor ground connection, remove motor and replace with a new one.

Normally, this mechanism should require no additional lubrication. However, a drop of any good machine oil on the turntable shaft bearings, motor bearings, and frictional surfaces once a year will do no harm.

CAUTION: Do not lubricate the trip mechanism or allow any oil to come in contact with the idler wheel.

Page 11: