Harman-Kardon Rabco linear-tracking turntable

Long ago my old roommate in college had a Rabco, it was stolen, and he replaced it with a Harman-Kardon Rabco which served him well for about 30+ years. Now it's locked up. He says he thinks it's the platter bearing, but he's not the most intuitively mechanically adept until he learns about a device. He used it a lot, with a very large disc collection of unobtainable material which he likes to transcribe to digital to "clean up" all the pops & ticks. He volunteers at the library and transcribes for them too.

Anyone got any experience with these turntables and any helpful advice? DIsassembly, cleaning, lube? What type of bearing? Is there a ball in the bottom? Replaceable ball or entire bearing perhaps?
 

thomash85715

Member
2006-06-14 11:33 pm
When you say "locked up" what does that mean? The platter rotation can be prevented by several things but a seizing of the main center bearing would seem pretty unlikely especially if the thing has been in regular use. What usually fails on these is the rubber uniwheel deep under the arm carriage. It is of a natural rubber that begins to melt after a while and must be replaced with a modern little tire as used in cassette machines to drive the hubs. I have also seen these where the motor bearing wears down and the motor itself sort of crashes internally and either rubs or stops completely.
If the arm carriage tire has melted onto the cylindrical roller and is gummed everything up, I suppose it is conceivable that the whole machine would stop since that cylinder gets a belt drive all its own off the center spindle. This is a hard machine to work on; both upper decks must come off and this only after the arm trim covers come off and the platter of course. But the rewards of good sound and elegant timeless design are worth the effort. Mine continues to work 40 years on. OK maybe 38. --Tom in Tucson