These booklets were distributed with National and Supro guitars and amplifiers in the early 1950s.
Things You Should Know About Your Electric Guitar:
Things You Should Know About Your Electric Amplifier:
Valco and its predecessor companies patented a number of inventions, improvements and designs over the years. All patents are in PDF format, and are in chronological order by the year they were filed (not the year they were awarded - I figure this makes more sense from a historical perspective).
1934 Pickup: This is a very early pickup design. This design was created by Paul Tutmarc (builder of Audiovox instruments) and Art Stimson in 1931; Stimson sold the design to Dobro for $600, and it was used in the Dobro All-Electric guitar (and clearly influence subsequent National-Dobro pickups). Not surprisingly, a nearly identical pickup was used in Audiovox instruments.
1935 National Electric Hawaiian: Drawings of the first National electric lap steel, the Electric Hawaiian model of 1935. Interestingly, there are no notes about the electronics - that was saved for the next year when the equivalent Dobro design was patented.
1936 Dobro Electric Instruments: Drawings and descriptions of the first Dobro electric Hawaiian and Spanish models, including diagrams of the pickups and controls.
1936 Neck Design: Drawings and notes on the neck and joint used on National-Dobro and Valco electrics.
1937 Violin Pickup: In the 1930s, musicians and inventors tried to electrify everything from guitars to mandolins to violins to organs, and National-Dobro was no exception.
1946 Adjustable Bridge: A design for an adjustable guitar bridge. The triangular saddles are an interesting idea, but as far as I know this bridge was never put into production.
1949 Neck Design and Body Joint: Drawings and notes on the Valco neck and joint that was used on many instruments in the '50s.
1949 Tuning Changer: This design was implemented on the National "Triplex" model lap steel, which could switch between three tunings with the flip of a lever.
1949 Tuning Changer: A variant on the Triplex design. As far as I know, this was never put into production; however, it does resemble the Stringmaster tailpiece manufactured by Rowe Industries that was often found on Magnatone lap steels.
1952 Pickup: The classic Valco "Vista-Power" pickup design that was used on the more expensive models though the company's demise in 1968. Note the early-style method of attaching the pickup to the neck (the reason some early '50s guitars have a screw through the fingerboard) that was soon dropped in favor of more conventional pickup rings. Also note that this is is a single-coil pickup, despite its resemblance to Gibson humbucking units.
1958 Silver-Sound Pickup: The oft-mentioned and oft-maligned bridge pickup that Valco intended to emulate the sound of an acoustic guitar. As is shown in the drawings, this is not a piezoelectric device - it is an electromagnetic pickup with an unconventional design.