50 Year Old Weathers Turntable
Quote:
Originally Posted by
Audiobeer
I'm wondering what kind of work would be needed on a NOS turntable sitting in it's original box for almost 50 years?
My old 1950's Weathers Turntable in original condition still works just fine.
For those offered by Surplussales Inc., the worst possible could be perhaps, the rubber parts aka, the platter mat which you can replace with a Cork Sheet from Pep Boys, the little rubber capstan you can carve out of a soft Rubber Eraser (Been There); the Weathers Rubber Tone Arm Mounting Base "hardening," with age actually is an asset. Consider cleaning and lubricating the platter shaft and the tone arm mounting base shaft and just a small drop of sewing machine oil in the bearings of the twoCompass Technical Inc., 33 RPM & 45 RPM motors costing $15.00 each. What! you are still waiting, Go for it! herki[QUOTE/]
AR-XA / AR-XB bouncing and skipping
Quote:
Originally Posted by
hjames
I had never paid much attention to Emma's AR turntable in the past because I remember a friend in college had an AR-XA that bounced and skipped on anything we played on it ... bad conduction from the floor or whatever!
I didn't realize Emma's was a different model ... So, before breakfast, I went into the attic and pulled it down.[ATTACH]53825
Revised 6:00:am 11/28/11
Supporting the platter bearing and the tone arm mounting base__ my AR-XA has a two inch wide "T" sub chassis with an very stiff coil spring at each extremity of the "T" plus an aged, shrunken out of shape, chunk of foam for damping in each coil spring in vertical motion.
This suspension system does nothing to prevent this 10 pound assembly from rocking violently out of control in the horizontal plane and vertical direction at a rate, approx' (10) HZ per second. A good high-end design will feature a rate of (1 to 3) Hz per second traditionally addressed with some form of viscus damping. Otherwise, these vertical & horizontal modes will seriously aggravate the identical natural resonance modes of the undamped AR tone arm.
Worse that, the spring at the end of the long section of the "T" _ where the tone arm mounting is located_ has the same spring compliance as each of the two springs directly under the much heavier platter assembly. All springs should have identical resonant frequency below (1 to 2) Hz to provide damping in vertical motion. This equality is achieved using springs of compliance yielding identical vertical deflection of each spring. This mean equal supported mass and loaded deflection at each spring.
One other serious problem exists in the AR-AX __ "the drive motor is located on the cabinet top panel" allowing horizontal motion of the platter to and from the motor capstan. The motor should be mounted on the sub chassis. This tiny motor only consumes 1.5 watt!
The best solution is to fasten the sub chassis with little bolts directly to the AR cabinet top panel and adding, internally to the cabinet, equalizing weights located so the entire assembly has identical weight at each corner. This design modification can executed by placing additional incremental weights externally at each corner which can be transfered internally at each corner of the cabinet.
You should then attach a 20 pound marble slab under the cabinet supported by four highly damped identical springs of_ extreme stiffness in the horizontal plane located in a triangular configuration __ to provide a well damped vertical resonance of some (2 or 3) HZ well separated from the natural typical (10 t0 16) Hz resonance of the tone arm. There are many low cost tiny "dash pot" vertical damping devices similar to the shock mounts in automobiles available in this industry.
The famous "Oracle" Canadian Turntable has three "spring" towers supporting their sub chassis. The current "Oracle" now features three viscous piston damping devices with awesome results. herki[quote]
