If memory serves, the smaller 1930s diameter was required to clear the 
jukebox mechanisms.  I've heard that Decca, gunning for the jukebox market, 
had made its first release in the slightly larger size and had to redo it. 
I don't know if they used different presses or adjusted the plate area 
appropriately- my guess is the latter.

Steve Smolian

----- Original Message ----- 
From: "Michael Biel" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Monday, May 18, 2009 4:05 PM
Subject: [ARSCLIST] Record Diameter (was: playback curves for some 78s)

I sent this out last night under a different subject title but didn't
see it get posted or even get a duplicate posting rejection, so I am
trying again with some added information.  Maybe my joke in last night's
revision of the subject line was blocked?

From: "Steven C. Barr" <[log in to unmask]>
> Reissues of original Columbia or Okeh records from the 1925-3? era
> are VERY commonly dubs...since the originals were 10.25" discs and
> the stampers don't fit onto modern-day 10" records...! Steven C. Barr

Get out a ruler and some records, Steve. You (and most others here) are
in for a big surprise. Those "oversize" Columbia pressings are the ones
that are 10-inches. Most other "10-inch" records are 9 7/8-inches.
Many Columbia/ARC pressings from the 30s are 9 15/16-inches, and
eventually got down to 9 7/8-inches. Yes it is true that the Columbia
and Columbia-OKeh pressings are larger than later records, but the are
not and never have been 10.25" . And many or most of the early George
Avakian produced Columbia re-issue sets were master pressings, at least
the earlier copies were.  New stampers were always produced from the
metal positives (mothers) because the center mounting hole sizes were
different in from the late 30s on, so the outer diameter of the original
metal part is not of consequence.  What IS of consequence, of course, is
the diameter of the outermost grooving, and that is what Steve was
really talking about.  I think that there occasionally were problems --
even in newly recorded items that had to be issued in a dubbed fashion
if the cutting engineer goofed when setting the outer cutting diameter
on the lathe -- but thre was enough lead-in space on most 1920s
Columbias and OKehs to allow them to be reissued on the slightly smaller
pressings from the later 30s.

Also, when those in the metric world call those records 25 cm, they are
the ones who are correct.

One other point, Edison Diamond Disc diameters can vary a great deal.
I've never checked to see if the outer grooving diameter on these also
vary, but the size the discs are ground down to after "printing" can be
seemingly random.

Mike Biel [log in to unmask]