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Mistsubishi LT-30 Arm Movement

TRC

TRC

Well-Known Member
I've been told that, while the platter is direct drive, the arm mechanism is belt. I've looks at the service manual for this table, and I'm not seeing a belt. This table has been boxed and in storage for a number of years. Due to medical issues I'd lost interest in the hobby. I'm gradually making a comeback, hopefully... Anyway, the arm no longer moves. That's why it had been placed into storage in the first place.. Any idea why this would be happening..?

Thanks,
TRC
 
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Odds are rhat one or more of the small wheat bulbs will also need replacing.

This TT is worth the time and money to do those things.

Cheers,

David
 
There's a long thread about LT-30 restoration on this site, and the service manual is on vinylengine.com. It will take some work and patience but definitely worth doing.
 
If you lift the headshell can you hear the queueing motor running? If so, its the belt in the tonearm which needs to be cleaned and replaced (as the old belts break down to goo)

I have the same issue with a project LT-30 I just got (and have a LT-22 in my current setup)
 
TRC said:
I've been told that, while the platter is direct drive, the arm mechanism is belt. I've looks at the service manual for this table, and I'm not seeing a belt.
Click to expand...

Any progress report? As mentioned, the table is well worth saving. If it's anything like my DP-EC10, there's three belts, two for the arm drive's timing pulleys, and one for the drive motor. All four need to be square profile to fit the pulley groves.

tonearm-belts.jpg


These have already been replaced. The old ones had turned to goo and were a PITA to clean out of the white pulleys' tracks, but you do want to get them as best as possible. The drive motor mentioned is the vertical black blob top right in this pic. You can also see the wheat grain bulbs mentioned top center. Two of mine were burned, but I replaced all four while I was in there. Standard stock at radio shack, but not sure where you'd find them now.
 
No, I'm afraid not. With the holidays, plus being sick.. I've just not had time. So you're saying the motor itself is belt driven also..? Even though it says direct drive..? Sounds like my Nakamichi cassette decks - says direct drive, but is actually belt.
 
AugustWest74 said:
If you lift the headshell can you hear the queueing motor running? If so, its the belt in the tonearm which needs to be cleaned and replaced (as the old belts break down to goo)

I have the same issue with a project LT-30 I just got (and have a LT-22 in my current setup)
Click to expand...
Yes, I can hear the motor running.. just no movement.
 
I fixed one years ago, and even though I did a slapdash job since I just used the salvaged belts I had around . It changed my mind about linear tables, and I assume correct belts would have made it even better. I believe it would be well worth getting your table fixed, either using the manual at Vinyl Engine and doing it yourself, or having someone else do it. No doubt there are better tables, but not for close to what repairs would cost.
 
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Yup, the motor I was talking about is strictly for the arm drive mechanism. Here's a better view of my table that I imagine is a fairly similar setup ...

mitsubishi-dp-ec10-guts.jpg
 
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About 2 months ago I finally finished up replacing the 2 belts and some bulbs that were needing replaced. Read the somewhat long forum acct (22 pages) of what I and others encountered along the way to fix our LT 30 turntables. definitely worth fixing.
 
bobinaz said:
About 2 months ago I finally finished up replacing the 2 belts and some bulbs that were needing replaced. Read the somewhat long forum acct (22 pages) of what I and others encountered along the way to fix our LT 30 turntables. definitely worth fixing.
Click to expand...

What purpose do the bulbs serve?
 
The bulbs shine through slots in the matte black masking disk to time the drive's movements. There's photo sensors on the other side of the disk that actuate the motors when exposed to the light. Pretty trick for the day, eh.

* See post #12 for a pic showing the masking disk ...
 
sKiZo said:
The bulbs shine through slots in the matte black masking disk to time the drive's movements. There's photo sensors on the other side of the disk that actuate the motors when exposed to the light. Pretty trick for the day, eh.

* See post #12 for a pic showing the masking disk ...
Click to expand...

I had a deck one time, don't recall maker / model, where the underside of the platter rim was magnetically coated, and a cassette tape head was mounted, and this was used to monitor the speed. Pretty cool :)
 
TRC said:
I had a deck one time, don't recall maker / model, where the underside of the platter rim was magnetically coated, and a cassette tape head was mounted, and this was used to monitor the speed. Pretty cool :)
Click to expand...
Denon and Sony used this magnetic rim tach feedback system.
 
Mitsu had an interesting setup for speed control - the gauge was cast into the bottom of the platter and was read by sensors.

mitsu-strobe-001.jpg


That casting was reflected into a window in the control panel to give a visual indication of speed.

dpec10speed.jpg


The table also read arm set down position for different size disks using a prism tower that beamed a light across the top of the platter and reflected back from prisms set into the platter surface.

light-tower.jpg


Short version - lots of interesting features on this series.
 
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