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Superscope / Marantz TDR-830 has noisy motor

62vauxhall

Addicted Member
This is likely a long shot but for the sake of increased exposure, I am posting this here on AK as well as on Tapeheads.

Due to a fondness for 8 track recorders, last weekend I gambled $10 on this garage sale TDR-830. Before a long distance move a couple of years ago, I pared down my assortment of 8 track recorders and that cull had me sell a TDR-820. It was not one of those I chose to keep as one feature I liked was absent but it was a descent machine and I got a good price for it.

The recently acquired TDR-830 is in not bad cosmetic shape but it needs rehabilitating. First up was a partially seized motor. I drizzled some oil down the shaft beneath the pulley and let it sit for 48 hours. That freed up motor rotation but it is distinctly noisy.

My hope was that there would be some convenient way to disassemble the motor sufficiently to clean and properly lubricate it but that does not seem to be the case. Also, there is no maker's name or part number anywhere on the motor housing or on the motor itself once it had been extracted from that housing. Unless it is underneath the gray plastic "skin" surrounding it.

Before I begin bending back the metal tabs now in view that seem to be holding the motor together, I thought I'd ask here if this motor can in fact be taken apart and re-lubricated. Or, ask if anyone can identify the motor itself so as I can try looking for a replacement.

The only number I have seen so far has been in the service manual parts list which is MM1320120 and has no general relevance that I have found.

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I proceeded with cutting off the shrink wrap skin and it did reveal a part number for the motor but no manufacturer's name and no hits online when searching that specific part number. Therefore the next step was disassembling the motor.

Removing the rotor and tapping the case dislodged a good quantity of carbon powder. The brushes still had what looked to be sufficient carbon material in place to function. So I blew out the carbon dust, cleaned and lubricated both bearings and reassembled the motor which now turns freely with no detectable noise.

I could be wrong but seeing that much carbon powder from abraded brushes inside the motor made me suspect that this TDR-830 has many hours on it. The garage sale where it was obtained also had on hand about 200 8 track cartridges which were mostly C&W. It made me imagine that the garage sale was to dispose of goods belonging to someone recently deceased who must have, at one time, liked listening to country music a lot.

The motor will be re-installed soon to further assess what else is wrong with this deck. The only other flaw I have noticed so far is that the left meter's needle does not move. But I opened up both meters and loosened up the pointers.

Now onto other issues I've now found.
 
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