I would have sworn it wasn't, but, by gum, looking at it again in daylight you are absolutley right. It is much wider than a normal grove, but a spiral grove it is. So it would work for any of the 3 kinds of sets, just being harmless surplusage on M sets. I think I was looking at the "trees" (radial segments) when I should have been looking at the "forest" (the record as a whole). Or maybe just yet another "senior moment."
Clay
Arthur W. J. G. Ord-Hume's Laws of Collecting
1. Space will expand to accommodate an infinite number of possessions, regardless of their size.
2. Shortage of finance, however dire, will never prevent the acquisition of a desired object, however improbable its cost.
Wolfe wrote:I'm wondering what the purpose of the spiral groove is anyway. Maybe there so the shellac biscuit would set up properly in the record press?
OrthoSean wrote:The reason for the spiral in the blank sided disc was usually so if these were stacked on a changer the needle would hit the spiraling groove and the disc would reject.
Wolfe wrote:I'm wondering what the purpose of the spiral groove is anyway. Maybe there so the shellac biscuit would set up properly in the record press?
OrthoSean wrote:The reason for the spiral in the blank sided disc was usually so if these were stacked on a changer the needle would hit the spiraling groove and the disc would reject.
I have one of these records which has a blank red label as well as the other mentioned features. It is part of set DM 531: Mendelssohn Concerto in E Minor For Violin and Orchestra played by Yehudi Menhuin with the Orchesre Des Concerts Colonne conducted by Georges Enesco, recorded May, 1938 by HMV. My set is on Victor circle label.
While playing the set today I did try the spiral and, although it is much wider and deeper than a normal record grove, it is functional.
Clay
Arthur W. J. G. Ord-Hume's Laws of Collecting
1. Space will expand to accommodate an infinite number of possessions, regardless of their size.
2. Shortage of finance, however dire, will never prevent the acquisition of a desired object, however improbable its cost.