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Beolover SyncDrive: DC Platter Motor Replacement for Beogram 4002 and 4004 (Type 551x and 552x)

Late Beogram 4002 and the 4004 (Types 551x and 552x), which have DC platter motors instead of the earlier synchronous AC motors usually suff...

Friday, March 17, 2017

Beogram 4002 (5513): Restoration of Arm Lowering and Tracking System

After the first evaluation of this Beogram 4002 my starting point of its restoration was as usual rebuilding the arm lowering and tracking systems. My customer already did the cleaning and lubricating of the damper and solenoid linkages, so all that was left was to remove the linkage between the damper and the tonearm. This requires taking out the sensor arm assembly. This shows the arms from the back:
Taking out the sensor arm requires removal of two screws at its base:
Then the linkage can be removed:
After cleaning and lubricating the bearing I put the arm back together and bolted it back onto the carriage. Then it was time to adjust the arms orthogonal to the carriage tracks and parallel to each other:
Once this was done, I installed my LED based tracking sensor light source replacing the incandescent lightbulb that originally illuminates the tracking sensors. This shows old and new light sources in direct comparison. The LED is in exactly the same spot as the filament of the bulb:
On the back of the LED unit the blue trimmer is used to adjust the light intensity. This makes it much more straight forward to adjust the tracking sensor sensitivity:
This shows the original light source in place:
And the replacement:
The final step of the carriage restoration was to clean the threaded rod that advances the carriage and put a new pulley on. This shows the original cracked and glued on (shudder!) plastic pulley:
After breaking it loose in pieces from the rod the new precision turned aluminum pulley could be installed:
Very Beolovely, if you ask me! If you wanted to upgrade your 400x to a pulley like this, send me an email or use the contact form to the right. I'll be happy to get you in touch with the Master of Pulleys! By the way: All my parts featured on this blog are available to other enthusiasts, too! On to restoring the electronics!






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