[78-L] aluminium disks

[Ken Matheson]

John Wright wrote;
A collector wrote to me today. Maybe members here can help me advise him 
of what he has:

>>>

The disk is aluminium with a blue material applied to it - like vinyl or 
wax. The disk has a centre hole and an additional hole about 1" away. 
The labels are paper either typed or hand written. All of the disks are 
Jazz recordings dating from the late 1940s to early 50s.? Typical of the 
unusual ones is one?featuring Fats Navarro. I've googled it and it's a 
session from NYC 20th September 1949 and features Max Roach amongst 
others.

The same recordings are available on standard 78s.

What is this disk?
 
Radio stations in the 50’s used these disks to make recordings to play
back at a later time. They were usually as big as, or bigger than the 33’s
we have now. There were smaller ones 78 size and smaller that were
also in use. They were for the consumer market, i.e. home recording,
churches, bands, singers, etc. When real to real became popular most
of the non studio record cutting Went away. The extra holes were for apin on the cutting table to keep the disk from slipping.