Columbia Viva-Tonal 650

[Edisone]

Here are two patents for the soundbox and horn of the 650. I haven't taken off the back to be sure, but from the front with the grille removed, the horn sure does look like the one in the patent.

Interesting variation on the diaphragm: this patent shows it as one piece, with the outer part being either ground or stamped thinner than the middle. That's one of the possibilities mentioned in the actual diaphragm patent, but the main idea in that patent was to cut out the middle of .002 metal & attach .004 .006 or even thicker material for the center. I'll hafta check my new thing to see how it was made.

Brunswick accomplished the same idea by adding 1 or 2 reinforcements to a solid diaphragm, while Victor used a "spider".

[Joe_DS]

Many thanks for posting this.

I had no idea that the horn fitted into the smaller 600-series models used a divider. I'm wondering if this did any good, from a sonic standpoint, our if it was just a way to get around any patents applied for or held by Victor, etc., for similarly shaped, non-folded horns.

Joe