[Vintage-Audio] Stylus Tracking Weight

[Duane Fischer, W8DBF]

At what point in time did the depth to which the stylus penetrated down into the
groove become more shallow? Was it prior to stereo or after it became a saleable
medium? 	
	
When did the tracking weight drop from 4-6 grams down to one gram or less? 	
	
What was the groove width on the mono vinyl recordings of the fifties?  What was
the groove width on the stereo vinyl recordings when they first came out? Did
this width become more narrow as time went along? 	
	
Thanks. 	
	
Duane W8DBF