Rerurn to Romy the Cat's Site
In the Forum: Analog Playback
In the Thread: Turntable speed analysis.
Post Subject: Belts, Strobes, and Mass X Velocity SquaredPosted by Paul S on: 6/12/2012
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N-set, you may be aware that back in the day strobes were popular for *other* reasons, so they were "around". We just darkened the room and varied the strobe until we could see the range(s) of belt motion. The motions were visible at different strobe frequencies, hence my "conclusions".
Remember that Romy's platter is HEAVY, and its rotational mass is very high. If I understand correctly, this rotational mass is also (intentionally) high compared to the motor torque. I don't know how to relate to audibility or even relevance the incremental differences shown on the plots, but those spikes appear to be larger than I would suppose from anything the belt could do so "suddenly" to that moving platter, given the relative "influence" of the parts in question. Dang me for even bringing it up, but this sort of repetitive "spike" could be from a "fault" in a bearing. Should be easy enough to check with a stethoscope.
Best regards,
Paul SRerurn to Romy the Cat's Site