Dual-1219-tt-sm2维修电路原理图.pdf

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1、Dual 1219, 1229 Service for Amateurs Im a retiree who is always looking for a new and challenging hobby. I am an amateur hobbyist, not a working turntable repairman. To that extent use this guide at your own risk. I have been a hi fi addict since the late 60s. Just before Christmas 2008 I got the bu

2、g to get my old hi fi equipment out, a 1974 Marantz 2270 and a Garrard Zero-100C I bought new, still have all the boxes and paperwork for. After a little work on the receiver and a proper service of the Garrard this equipment still makes some beautiful music. I also upgraded my speakers, replacing s

3、ome cheapie interim Kenwoods that replaced my Pioneer CSR500s which sadly were destroyed. The new speakers are some early 90s Klipsch Quartets in oak oil that look beautiful and sound terrific. While I was waiting for the Garrard to be serviced I got interested in Dual 12-series tables. My brother a

4、lways had duals and he swore by them, his last table was a 1229Q. I looked on E-Bay and I wound up buying a US version of the 1219, a 1229 and a couple of junk for Europe metric 1219s mostly because one of them had a choice Dual base with the fold down front and also because some parts are interchan

5、geable. I have 1 of the Euro tables, the for US 1219 and the 1229 up and running and they are amazing to listen to. The other Euro table was missing parts and the gimbal bearings were destroyed so it is parts only. Above are pictures of the Dual 1229 I recently purchased on E-Bay for the princely su

6、m of $69 + shipping. It had a Shure V15 Type III cartridge and no base cabinet. The base cabinet was another $9.99 on E-Bay + shipping. It was quite tired when I got it probably never having been serviced since new. The start/stop switch was loose and the speed control lever was stuck. Caution: Neve

7、r force a stuck speed control. If it wont move easily it must be cleaned and lubricated. The plastic speed control cam will shatter if you force the control lever. The table was dusty and dirty and had a tweaked transport screw in one corner. I did a quick cleanup of the chassis with a paint brush,

8、replaced the transport screw from a donor table, released the stuck start switch and tightened the set screw on the bottom of the chassis and cleaned up the speed control (detailed description later) just to get the table to spin up and allow me to finish checking it out. The table actually ran in s

9、ingle play 33rpm on the 12 inch record setting only. The cueing lever also seemed to work well. While the other speeds worked the tone arm would not move to 10 inch or 7 inch positions in single play mode. Additionally after a few minutes of running the drive motor became noticeably noisy. I then in

10、serted the multi-play stacker spindle and very carefully moved the mode lever to the multi-play position. RadioFans.CN 收音机爱 好者资料库Caution: Never force a stuck single-multi play mode control. If it wont move with very light effort and you force the lever you will break the plastic ears off the bottom

11、of the gimbal ring. There are no service parts for this, you will either scrap the table or have to replace the complete tone arm and gimbal assembly if you can find one. My mode lever moved quite easily and the tone arm did rise, a good sign that the gimbal assembly was intact. I put a couple of ol

12、d records on the stacker and hit start. The tone arm rose from its rest, a record dropped and the tone arm set back down on the rest and the table turned off. I also manually moved the tone arm to the starting groove of the record and found quickly that in multi-play mode the tone arm was dragging a

13、nd would not track. These symptoms are typical for a table that is stuck with old grease, has a broken rubber washer in the single-play multi-play tone arm height control, needs a new tone arm clutch (sometimes referred to as a “guide white” or “steuerpimpel”) and a drive motor that needs to be disa

14、ssembled, cleaned and re-lubed. Below are some better step-by-step descriptions of how I brought this table back to life. Some differences between early and later 1219 tables and 1219 and 1229 tables Some early 1219s were built for use in either US or Europe with a 110v/220v switch on the motor term

15、inal box and had hardwired phono cables and no separate chassis ground wire. Many of these also had 50cycle strobe patterns on the platter. Use of US 110v 60cycle power required a change of the motor pulley to produce set speeds. Metric record sizes were stated on the switch mask. Later United Audio

16、 units intended for US only had no 110/220v switching, had RCA output jacks under the table and had ground wires. They had no strobe patterns on the platter. !219s had metal speed control levers and 2 piece pitch control knob knobs where 1229 tables had 1 piece pitch control and plastic speed contro

17、l knob. Preparing the table for service After disconnecting the table and moving it to a work table I first removed platter retaining clip and the platter, cartridge and head shell and the counterweight at the back of the tone arm. Make sure the tone arm is locked on the rest at this point. Next unl

18、ock the transport screws, tilt them out of their slots in the mounting board and lift the table out of the base. I have found with careful handling it is safe to work on either side of the turntable when it is placed on a thick soft layer of terrycloth bath towels. Servicing the speed control mechan

19、ism Disassembly The example speed control is a 1219 unit which has slightly different pitch knobs and speed switch lever. RadioFans.CN 收音机爱 好者资料库1. With the table right side up remove the vinyl keeper washer on the idler wheel and set the idler wheel aside. After the wheel is removed its a good idea

20、 to put the keeper washer back on the idler shaft. !229 speed control switch shown above has plastic lever and 1 pc pitch knob. 2. Turn the table over and carefully set it on a thick layer of towels. Pictured below is the speed control mechanism. 3. Find the actuator spring that connects the idler w

21、heel arbor on the speed control mechanism and remove the E clip that retains it to the shaft on the motor switch arm and lift the spring off the motor arm shaft. 4. Remove the nut on the bottom of the speed control that holds the detent plate (see above) Carefully remove the washer and detent plate

22、from the bottom of the speed control switch shaft. All units have a ball and spring that lock the detent plate into position for the various speeds. On some units the ball and spring are loose parts and should be removed and set aside. I have found at least one that the ball was captive in the end o

23、f the hole in the speed control housing but make sure these parts dont fall out and get lost. 5. Turn the chassis right side up again and lift out the speed control switch lever and the fluted aluminum pitch control knob. 6. Under the pitch control knob above the pitch pointer is a fairly large C cl

24、ip. This C clip must be removed then the pitch pointer and a wave washer come off above the chassis. 7. Turn the chassis upside down. Grasp the speed control housing and the idler bracket as a unit and remove the 2 screws that hold the assembly to the bottom of the chassis. Lift the assembly off the

25、 bottom of the chassis and try to do it without letting the cam spring push the whole assembly apart until you can get it out and look at how the idler bracket pin inserts into the side of the plastic cam. Once you see that you will have an easier time re-assembling the speed control. As an assembly

26、 aid I have some pictures below that show the speed control assembly removed from the chassis. Detent plate removed Speed control switch lever and pitch control knob removed-1219 2pc pitch knob. Large C-clip partially removed from pitch pointer A view of the idler bracket and plastic speed control c

27、am. Note how the pin on the idler bracket passes through the S-slot in the side of the plastic cam. Another view of cam idler bracket assembly to main housing Speed control parts laid out in order of assembly. Note parts above the “chassis” line assemble on top of the chassis and all others includin

28、g the 2 attaching screws in upper right corner of picture go below the chassis. Note the first part below the chassis is a washer with 2 small right angle tabs that must be assembled to the chassis so the center hole lines up with the hole in the chassis that the switch tube passes through. Note als

29、o that there is a step on the steel pin that the idler bracket slides on. This step down fits into a small hole in the bottom of the chassis to correctly align the speed control assembly. Make sure when installing the speed control to the bottom of the chassis this step down pin is located in the ch

30、assis hole before tightening the 2 mounting screws or the speed control will not work correctly and you may damage the speed control casting. Cleaning All parts of the speed control except the pitch pointer can be degreased easily with charcoal lighter and a hobby paint brush. Caution: The pitch poi

31、nter is a hard rubber and will be attacked by petroleum products. Use rubbing alcohol and a soft cloth only on this item. Reassembly 1. Once all old oil and grease are removed put a trace of Phono Lube or other very light lithium grease in the S-slot of the plastic cam and on the switch tube the cam

32、 swivels on. 2. Refer to the exploded view picture above and place the large spring back on the switch tube portion of the main speed control casting. 3. Smear a drop of 10w30 motor oil on the idler bracket shaft and slide the bracket up and down the shaft a few times to make sure it moves freely. 4

33、. Raise the idler bracket almost off the shaft, place the plastic cam over the end of the big spring on the main casting, engage the idler bracket pin in the S-slot of the cam and slide the cam and idler bracket together down the switch tube and idler bracket shaft. 5. Hold the cam down on the switc

34、h bracket against the spring force and install the tab washer above the cam on the switch tube and the small spring on the top of the exposed portion of the idler bracket shaft. 6. Carefully start the idler bracket and switch tube through the chassis holes from below the chassis. 7. Rotate the tab w

35、asher to engage the tabs in the slots in the chassis. 8. Carefully center the idler shaft spring over the alignment hole in the bottom of the chassis and insert the idler shaft though the small spring and then the step of the idler shaft into the alignment hole. Make sure idler shaft spring is not k

36、inked or crushed and that the idler shaft step down pin enters the alignment hole in the chassis. 9. Maintaining assembly pressure on the speed control assembly install the 2 mounting screws to attach the speed control assembly to the bottom of the chassis. 10. Place the motor switch spring back ove

37、r the end of the motor switch link pin and re-install the small E-clip. 11. Turn chassis right side up and put a dab of Phono Lube on both sides of the wave washer and place it over the switch tube. 12. Place the pitch pointer over the switch tube, rotate it to engage the cam and re-install the larg

38、e C-clip. 13. Install the fluted pitch control knob and finally smear a little Phono Lube on the brass speed control switch shaft and insert it into the switch tube. 14. Turn chassis upside down again and re-install detent spring and ball in hole on bottom of main speed control casting. 15. Insert t

39、he pin of the detent plate into hole in bottom of plastic cam and install detent plate over the flats on the bottom of the speed control switch shaft and install cupped side of washer down against detent plate and install and lightly tighten the nut. 16. Turn chassis right side up. Idler wheel inspe

40、ction and installation The perimeter of the idler wheel must be perfectly round to prevent rumble and free of rubber glazing to supply proper traction. 1. Very carefully inspect perimeter of idler wheel to make sure it is free of flat spots. A common cause of flat spots is a table that was stored aw

41、ay with the motor switch left on so the idler wheel sits in contact with the motor pulley for a long period of time. 2. Very very small flat spots may be cleaned off by putting the idler wheel shaft flange finger tight in a drill press chuck (do not use a chuck key or you may collapse the flange and

42、 wreck the bearing) then lightly dressing the edge of the wheel with a fine emery board. If the wheel has more that very very small flat spots it must be replaced or it will rumble. 3. If it is only glazed the edges can be lightly feathered with 280 grit paper and wiped clean with alcohol. 4. Once t

43、he idler is in reasonable condition remove the vinyl keeper washer from the idler wheel shaft, coat the shaft with a drop of 10w30 motor oil, insure the fibre thrust washer is present at the bottom of the idler shaft, install idler wheel and keeper washer. Motor service Drive motor leads must be dis

44、connected from the switch box and the motor must be removed from chassis for disassembly, cleaning and lubrication. 1. Turn chassis upside down and remove the mains plug from the bottom of the switch box then remove the switch cover screw and cover and set aside. 2. Note that the terminals are numbe

45、red in the switch box. Make a list of which colored wire goes on what terminal post. 3. Use a small hook made from piano wire or brass tubing to aid in removal of wire connecters from switch box terminals. Place the hook under each wire terminal close to the terminal post and using other had to slig

46、htly rotate wire terminals on their posts gently lift terminals with the hook up and off the terminal posts. Be very careful not to apply side pressure to the plastic divider walls between terminals or you will break the plastic switch box. 4. After all wires are removed from the switch box turn the

47、 table right side up and using a 7mm metric socket remove the 3 motor nuts and lift the table off the motor assembly and set aside. 5. Before the motor is disassembled put a pencil or paint reference mark on the upper and lower shells to assure proper reassembly. 6. Wipe off the exterior of the moto

48、r before disassembly. 7. Loosen the motor pulley setscrew and remove the motor pulley. Carefully inspect the shaft surface near the motor pulley setscrew contact area to assure there are no burrs on the motor shaft. If there is it must be dressed down carefully with an emery board or you will score

49、the motor bearing when you pull the shaft through the bearing. 8. Remove the 2 frame screws nuts and spider washers. Using an expanding jaw plier or snap ring plier inserted next to one frame screw insulator recess then the other carefully force the shells apart a little at a time until they separat

50、e. 9. Carefully wipe any debris out of the inside of the motor cans. 10. If the armature has rust on its exterior carefully sand it off with 280 wet dry paper. Do not get the dust in the bearings. 11. If bearings are varnished they should be degreased with the charcoal lighter. Otherwise put several