Boonshaft & Fuchs Direct Reading Frequency Response Slide Rule

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Country of manufacture: Denmark,            Date of manufacture: ____
Overall length: 34.9 cm,          Width: 12.5 cm,           Thickness: 1.1 cm           Weight: _____ gms.
Materials & Construction: Duplex construction; metal and Plexiglas frame. The cursor measures 6.0 x 13.6 x 0.8 cm and consists of metal runners holding a plexiglass lens. It is reversible, i.e., it can be removed and used on the 'back' side of the rule.
Scales: Individual slides (shown below) for frequency and for each of 24 different transfer functions. Each slide is approximately 42.5 x 0.8 x 0.4 cm and is printed on both front (amplitude ratio in decibels) and back (phase angle in degrees). The duplex construction of the rule allows decibels as a function of frequency to be read off the front of the rule and, simultaneously, phase angles as a function of frequency to be read off the back of the rule. Red printing is used for negative values. Instructions for its use may be found here, Hughes, Richard Smith, The Hemmi 301 and the Boonshaft and Fuchs Slide Rules, Journal of the Oughtred Society, 20:2, Fall 2011, pp 17-26.
Condition: C4-C5 (Minimal to Normal signs of use)
Came with: Light brown zippered leather case (48.3 x 22.9 x 3.8 cm closed); holds slide rule, cursor, cleaning brush, individual scales

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Front of Slides


Back of Slides

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