DUAL 1237 Turntable Continuous Tripping

7/22/2009 8:44:22 PMDave Froehlich

Hello All,
I hope that this turntable isn't too new for this forum. It has a mechanical problem. I can see it happen but it's difficult for me to describe. But the result is continuous tripping. At the end of a cycle, it cycles again. The needle touches the record for a second as well. If a lever is held back underneath, then the cycling does stop. But I can't constantly keep my hand under the turntable. Something is out of adjustment or has gotten stuck. If anyone knows the solution to this problem, please help.

Thanks,

Dave

7/22/2009 9:36:20 PMWarren

Not all that sure about that model, but there should be a small friction contact with that lever when the tone arm moves back. I think it's like a little nylon dot that makes the drag friction. with the turn table platter removed, cycle it buy hand, look at the parts that move when the tone arm is returning. You should be able to see what is moving, and what should be but is not.

7/22/2009 11:51:15 PMDave Froehlich

Warren,
I did that but I can only move it by hand and prevent it from sliding down and making it trip. Nothing holds it up after the cycle is over so it cycles over and over and over.

Thanks,

Dave
: Not all that sure about that model, but there should be a small friction contact with that lever when the tone arm moves back. I think it's like a little nylon dot that makes the drag friction. with the turn table platter removed, cycle it buy hand, look at the parts that move when the tone arm is returning. You should be able to see what is moving, and what should be but is not.

7/23/2009 8:13:17 AMcharlie

:Warren,
: I did that but I can only move it by hand and prevent it from sliding down and making it trip. Nothing holds it up after the cycle is over so it cycles over and over and over.
:
:Thanks,
:pull the platter off.Should be able to see where large round cycling wheel has a gap in the teeth.There should be a small sheet metal piece that hinges at this gap so wwhen it is in one position it acts as the missing teeth on the wheel.Make sure the grease hasn't hardened up stopping the small segment from swinging back out of the way.Should be under a slight spring pressure to swing it back out of the way.The trip assembly momentarily pushes it into the gear path to stat the reject cycle.
:Dave
:: Not all that sure about that model, but there should be a small friction contact with that lever when the tone arm moves back. I think it's like a little nylon dot that makes the drag friction. with the turn table platter removed, cycle it buy hand, look at the parts that move when the tone arm is returning. You should be able to see what is moving, and what should be but is not.

7/22/2009 10:31:44 PMCarl C

:Hello All,
: I hope that this turntable isn't too new for this forum. It has a mechanical problem. I can see it happen but it's difficult for me to describe. But the result is continuous tripping. At the end of a cycle, it cycles again. The needle touches the record for a second as well. If a lever is held back underneath, then the cycling does stop. But I can't constantly keep my hand under the turntable. Something is out of adjustment or has gotten stuck. If anyone knows the solution to this problem, please help.
:
:Thanks,
:
:Dave

Dave, Go here:http://www.vinylengine.com/phpBB2/index.php and scroll down to the Dual Forum and search posts for similar problems. If you Google 'Dual turntables' it will lead you to a lot of different links to Dual turntables. Hope you find what you are looking for.
Carl

7/22/2009 11:54:12 PMDave Froehlich

Carl,
Searching only searches Google which leads me to pages with owner's manual. The only problem I can find in that forum is about some hum. But I can find nothing else. Nobody has had any problems with continuous tripping. But I'm sure this has to be mentioned somewhere.

Thanks,

Dave
::Hello All,
:: I hope that this turntable isn't too new for this forum. It has a mechanical problem. I can see it happen but it's difficult for me to describe. But the result is continuous tripping. At the end of a cycle, it cycles again. The needle touches the record for a second as well. If a lever is held back underneath, then the cycling does stop. But I can't constantly keep my hand under the turntable. Something is out of adjustment or has gotten stuck. If anyone knows the solution to this problem, please help.
::
::Thanks,
::
::Dave
:
:Dave, Go here:http://www.vinylengine.com/phpBB2/index.php and scroll down to the Dual Forum and search posts for similar problems. If you Google 'Dual turntables' it will lead you to a lot of different links to Dual turntables. Hope you find what you are looking for.
: Carl

7/23/2009 1:38:06 PMBob Masse

:Hello All,
: I hope that this turntable isn't too new for this forum. It has a mechanical problem. I can see it happen but it's difficult for me to describe. But the result is continuous tripping. At the end of a cycle, it cycles again. The needle touches the record for a second as well. If a lever is held back underneath, then the cycling does stop. But I can't constantly keep my hand under the turntable. Something is out of adjustment or has gotten stuck. If anyone knows the solution to this problem, please help.
:
:Thanks,
:
:Dave
:
:
:Hi! Dave,
If you google (The Dual Reference Website) you will find a link for troubleshooting your turntable as well as where to get parts and service. Hope this helps. Bob Masse
:
:

7/24/2009 4:48:54 PMEdd

Sir Dave. . . .

In consulting the blow up of your problematic Dual unit, the main point of interest to you is my [RED] mark up of the item numbers 158 and 159. They are the key components of the reject cycling of the unit.

Initially, observe the BOTTOM of the platter unit and note that centrally there is a large cog gear surrounding the spindle hole in the platter.
That gear is normally ALMOST engaging into the large cycling gear that 158 and 159 are mounted on, I say almost, because the lack of a few teeth on it precludes the two gear surfaces from intermeshing.

That is possible and will be accomplished in three situations:

If you were to move the control knob / lever on top to initiate an automatic play cycle. The lever swings 158 and 159 over towards the edge of the cycling gear such that an appendage engages with the platter cog gear and the cycling gear moves forward just a bit and by that small movement is then actually able to inter mesh with the platters cog gear, and a mechanical cycle is started.
By the time that change cycle is completed, making a full revolution of the cycling gear, the same initially disengaged condition of the two gears is now present again.

That remains the case UNLESS you happen to not want to hear that selection and reject the mechanism into yet another change cycle.

The normal situation is for the record selection to be playing with the tone arm working s l o w l y across the record until it is met with the end grooving of the record. Simultaneously there is a light weight reject linkage that is making a concurrent movement with the tone arm of the set, but it is approaching the 158-159 pair and gradually displacing them towards engaging the cog gear to initiate a cycle gear action again. There is some slight friction coupling between 1tems 158 and 158, but the pronounced undulations of the ovate end of record grooving makes a smart transitional movement of the pair into rapidly engaging into a reject cycle.
Study those linkages that tie into items 158-159 and their required actions can then be visualized.

BUT the first thing to check now is the 159 item as it has a collar that has a shaft on the cycling gear that passes thru it, With time, the lubricant used between the two has a tendency of tightening / jelling / seizing up and the locking up of the mechanism into either no reject action possible or into a continuous reject action.

Check and see if those two items move freely. . . . mainly 159 as the other 158 item just rests atop it.

73's de Edd

Mechanical Blowup of Dual 1200 Series

7/24/2009 11:18:14 PMamended textual width indexing. . . velly solly . . .

Sir Dave. . . .

In consulting the blow up of your problematic Dual unit, the main point of interest to you is my [RED] mark up of the item numbers 158 and 159. They are the key components of the reject cycling of the unit.

Initially, observe the BOTTOM of the platter unit and note that centrally there is a large cog gear surrounding the spindle hole in the platter.
That gear is normally ALMOST engaging into the large cycling gear that 158 and 159 are mounted on, I say almost, because the lack of a few teeth on it precludes the two gear surfaces from intermeshing.

That is possible and will be accomplished in three situations:

If you were to move the control knob / lever on top to initiate an automatic play cycle. The lever swings 158 and 159 over towards the edge of the cycling gear such that an appendage engages with the platter cog gear and the cycling gear moves forward just a bit and by that small movement is then actually able to inter mesh with the platters cog gear, and a mechanical cycle is started.
By the time that change cycle is completed, making a full revolution of the cycling gear, the same initially disengaged condition of the two gears is now present again.

That remains the case UNLESS you happen to not want to hear that selection and reject the mechanism into yet another change cycle.

The normal situation is for the record selection to be playing with the tone arm working s l o w l y across the record until it is met with the end grooving of the record. Simultaneously there is a light weight reject linkage that is making a concurrent movement with the tone arm of the set, but it is approaching the 158-159 pair and gradually displacing them towards engaging the cog gear to initiate a cycle gear action again. There is some slight friction coupling between 1tems 158 and 158, but the pronounced undulations of the ovate end of record grooving makes a smart transitional movement of the pair into rapidly engaging into a reject cycle.
Study those linkages that tie into items 158-159 and their required actions can then be visualized.

BUT the first thing to check now is the 159 item as it has a collar that has a shaft on the cycling gear that passes thru it, With time, the lubricant used between the two has a tendency of tightening / jelling / seizing up and the locking up of the mechanism into either no reject action possible or into a continuous reject action.

Check and see if those two items move freely. . . . mainly 159 as the other 158 item just rests atop it.

73's de Edd

Mechanical Blowup of Dual 1200 Series

7/26/2009 11:31:54 PMDave Froehlich

Edd,
I found that a plastic piece at the other end of the control lever linkage had a broken part at the end. This used to keep it in place. I used a cable tie. What gave me a clue that it was the position of the control lever is when it got to the end of the cycle, if I held the lever towards stop the cycling stopped. If I let go, it would cycle again. There is a manual spindle in the turntable. With the cable tie in place, all it can do is return the arm and shut off at the end of a record. Moving the arm to the rest by hand, shuts off the turntable, and moving it towards the record turns it on. In other words. It is now a fully functional manual turntable with auto-return.
I'm not as mechanically inclined as I am electronically inclined. It's a little difficult for me to figure out an exploded parts view sometimes. Where is that black plastic piece? I did find the two parts you were talking about. I think they are the ones fastened under the large cycle gear facing the bottom of the deck of the turntable. They were easy to move. In fact no parts were stuck or gummed up. But the plastic piece had something on it to prevent it from sliding on the plate it's resting on. That bump or whatever it was had broken off, allowing it to slide and allowing the lever to rest in the reject position.

Thanks very much,

Dave
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:Sir Dave. . . .
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:
:
:In consulting the blow up of your problematic Dual unit, the main point of interest to you is my [RED] mark up of the item numbers 158 and 159. They are the key components of the reject cycling of the unit.
:
:Initially, observe the BOTTOM of the platter unit and note that centrally there is a large cog gear surrounding the spindle hole in the platter.
:That gear is normally ALMOST engaging into the large cycling gear that 158 and 159 are mounted on, I say almost, because the lack of a few teeth on it precludes the two gear surfaces from intermeshing.
:
:
:
:That is possible and will be accomplished in three situations:
:
:
:
:If you were to move the control knob / lever on top to initiate an automatic play cycle. The lever swings 158 and 159 over towards the edge of the cycling gear such that an appendage engages with the platter cog gear and the cycling gear moves forward just a bit and by that small movement is then actually able to inter mesh with the platters cog gear, and a mechanical cycle is started.
:By the time that change cycle is completed, making a full revolution of the cycling gear, the same initially disengaged condition of the two gears is now present again.
:
:That remains the case UNLESS you happen to not want to hear that selection and reject the mechanism into yet another change cycle.
:
:
:The normal situation is for the record selection to be playing with the tone arm working s l o w l y across the record until it is met with the end grooving of the record. Simultaneously there is a light weight reject linkage that is making a concurrent movement with the tone arm of the set, but it is approaching the 158-159 pair and gradually displacing them towards engaging the cog gear to initiate a cycle gear action again. There is some slight friction coupling between 1tems 158 and 158, but the pronounced undulations of the ovate end of record grooving makes a smart transitional movement of the pair into rapidly engaging into a reject cycle.
:Study those linkages that tie into items 158-159 and their required actions can then be visualized.
:
:
:BUT the first thing to check now is the 159 item as it has a collar that has a shaft on the cycling gear that passes thru it, With time, the lubricant used between the two has a tendency of tightening / jelling / seizing up and the locking up of the mechanism into either no reject action possible or into a continuous reject action.
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:Check and see if those two items move freely. . . . mainly 159 as the other 158 item just rests atop it.
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:73's de Edd
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:Mechanical Blowup of Dual 1200 Series
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