KL-1 Slide Rule

KL-1 Operations, Formula Tables

Derived from automated enumeration software at the wonderful slide rule site http://nsg.upor.net/slide/

The Soviet era KL-1 circular slide rule is a beautiful little mechanical calculating device. From my admittedly sparse research, they seem to have been made at a couple of factories in the 1960s and are for sale on eBay/Etsy for $30 to $60 or more(!?), depending on condition (scratching on glass, browning of dials, whether it comes with a paper box or bakelite case).

With a few twists of the knobs, you'll be calculating homebrew radio LC tank resonant frequencies, pendulum periods, BMI, designing spiderweb antenna coils, etc. See if you can recognize the equations from the tables below to plug in variables and constants!

KL-1 "pocket watch" slide rule

KL-1 "clone" made from laminated paper

Below, find tables of operations and formulae that can be performed on a KL-1.

A & C scales are the squares and normal scales on the front rotating disc, moved by twiddling the knob with the black dot. DI refers to the fixed normal scale (reciprocals of C) on the flipside. The Russian manuals refer to the DI fixed index marker as "pointer" and the moveable indicator as the "arrow", or cursor in analogy below to a regular straight slide rule.