Reisner Valves and the Stahnke Valve
By Robbie Rhodes
I asked Wayne Stahnke today if he had ever seen Reisner valves with return springs. His answer was "yes and no"!
To check-out the breadboard electronics for the new IMI Cassette Converter he bought a set of horseshoe chest valves from Reisner. When he asked if the valve had a return spring, he was told that it did not, but they could send him a set of return springs which he could install himself. But the springs received from Reisner had such inconsistent forces that he threw them out and had a new set made to his own specification.
Since Reisner offered springs I assume that they sometimes supplied valves with return springs installed, which explain why "some do and some don't" contain springs.
The Reisner horseshoe valves (with proper springs) worked okay in the Ampico A piano, but were bulky and required a large shroud enclosing the valve assembly in order to muffle the clicking noise. That's why Stahnke designed his own valve: he wanted it quiet and small. The resulting valve was less than 3/4-inch square by about 2-1/2 inches long, and quiet enough that no muffling of any kind was needed. He thinks that he measured the "on" and "off" delays as 6 milliseconds each. That's pretty speedy!
Thanks for your offer to supply me with some different valve designs for comparative testing. When I'm ready, in one or two months, I plan to "put out the call" to everyone.
-- Robbie Rhodes
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(Message sent Fri 12 Jan 1996, 05:31:31 GMT, from time zone GMT-0800.) |
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