Decade Resistance Box Hookup Guide

Contributors: Byron J.
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A decade box is a tool that contains resistors of many values accessed via mechanical switches. Adjust the knobs to output any of the discrete resistances offered by the box.

SparkFun Decade Resistance Box

SparkFun Decade Resistance Box


They are known as decade boxes because they have controls that correspond to the digits in a decimal number - a control for the tens position, a control for the hundreds position, and so on.

Reading a Decade Box

Traditional decade boxes looked like something out of Dr. Frankenstein's lab - large wooden enclosures, with engraved front panels and big Bakelite knobs. They were available in three main types - resistance, capacitance and inductance. This kit is for a decade resistance box. It allows you to quickly and accurately dial in a specific resistance value between 0 and 999,990 Ω, in 10 Ω increments..

In this hookup guide, we'll first assemble the decade box, then explore its application as a design aid and a test instrument.

Necessary Tools

Additional Tools and Supplies

Optional Materials

The decade box can be assembled to fit in an enclosure or behind a front panel. In this tutorial, we'll build it into a cast aluminum enclosure.

432,640 Ohms, Anyone?

If you want to build yours into an enclosure, you'll need the following.

  • Aluminum enclosure
  • Removable tape, such as painter's or gaffer's tape
  • Center Punch and hammer
  • A vise or clamps
  • A drill press or hand drill
  • A set of drill bits, or a step-drill

Suggested Reading

If you aren’t familiar with the following concepts, we recommend checking out these tutorials before continuing.

How to Solder: Through-Hole Soldering

This tutorial covers everything you need to know about through-hole soldering.

Connector Basics

Connectors are a major source of confusion for people just beginning electronics. The number of different options, terms, and names of connectors can make selecting one, or finding the one you need, daunting. This article will help you get a jump on the world of connectors.

Voltage, Current, Resistance, and Ohm's Law

Learn about Ohm's Law, one of the most fundamental equations in all electrical engineering.


A tutorial on all things resistors. What is a resistor, how do they behave in parallel/series, decoding the resistor color codes, and resistor applications.

Button and Switch Basics

A tutorial on electronics' most overlooked and underappreciated component: the switch! Here we explain the difference between momentary and maintained switches and what all those acronyms (NO, NC, SPDT, SPST, ...) stand for.

Electric Power

An overview of electric power, the rate of energy transfer. We'll talk definition of power, watts, equations, and power ratings. 1.21 gigawatts of tutorial fun!

How to Use a Multimeter

Learn the basics of using a multimeter to measure continuity, voltage, resistance and current.

Also, it is recommended to check out this tutorial on enclosure modification:

tutorial for enclosure modification
Tutorial for Enclosure Modification