By chance I found this: US. Pat. 3.418.418 (http://analogguru.an.funpic.de/patents/UsPat_3418418.pdf) assigned to D. R. Wilder on Dec. 24, 1968 (filed: May 25, 1964).
Funny, it looks very close to: ....the univibe (and clones).
So the patent states:
Lamp should be : "General Electric No. 19 Frosted"
LDR: "B-731-04-red"
...whatever this means (red: selected?). Maybe someone has an old electronics catalog or spec-sheets ?
interesting project: 1964-Phaser with pnp-ge-trannies... back to the "vintage"-roots ;D
analogguru
What a fascinating bit of trivia!
This appears to be a valid patent from 1964, predating the Univibe or its precursor, the RT18. Both the Univibe and the RT18 used LDRs modulated by an incandescent lamp, part of Claim 1. One wonders how the business situation played out.
I can't remember - does the Univibe case have notes like "Patent xxxxxxxxx, yyyyyyyy, zzzzzzzz" on it? Is one the same as this one if they're there?
Or did the Japanese company either patent-snipe, or parallel-evolve a very similar circuit?
Was there a court battle, or did the Japanese company have a license?
Was this one of those situations where Wilder could not buy enough justice? Or is this why the Univibe was never made in that great a quantity?
cool :)
will have to wait for RG to build one and post clips :)
cheers
ulysses
you really want to know it ?
ok, here is the "Tube Univibe" in: Us. Pat. 3.257.510 (http://analogguru.an.funpic.de/patents/UsPat_3257510.pdf) assigned to M. D. Burkhard on June 21, 1966 (filed: Oct. 15, 1962)
Have a look at the interesting capacitor values for the phase shift stages, familiar ?
analogguru
Any updates on this topic?
I can add that the engineer responsible for the Univibe was Mr. Fumio Mieda who was a staff engineer at Shin-Ei. These days, he was instrumental in developing the Nu-Tube, the Korg / Noritake Itron device that is in the Vox MV mini-head and the the Nu Tube Screamer.
He has never mentioned in any interview I've read, a reference to prior art... it would be interesting to hear what that was all about.