RCA Recording facilities worldwide February 1940
by Ray A. Rayburn
In order to standardize operations worldwide, in February 1940 RCA issued their "Master Reference Book for Disc Recording" as a confidential in-house document. Only 15 copies were made, and I believe I have the only copy left in existence.
The 386 page book included full manuals on all the equipment used by RCA to make recordings including schematics and photos. It covered Microphones, all electronics, loudspeakers, disc cutting equipment, turntables, test equipment, test procedures, and in-house standards.
You can download the entire book from my website here:
Ray A. Rayburn