Archive of Collections

Archive of Collections

Details and Image

Item#	Type	Model No.	Match No.	Variant No.	Model Name	Maker	Country	Production or Serial No.	Material	Scale Length	Date	Condition
KEU640	Linear	Mystery	Unknown	n/a	Mystery Duplex (Filter Dept.)	Keuffel & Esser	USA	5304	Engine divided celluloid laminated mahogany	"20"	1945	C5

Notes: "Special order/design slide rule made for making filter calculations, possibly for electronic filters or mechanical filters. The slide rule was probably used for designing the filters based on parameters using the R, SI, TI1, and TI2 scales. Has a DIF scale which I have never seen on a K&E slide rule."

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