Description
Dekabox DC-40 Decade Capacitor 1.111uF 400V DC Max Electro-measurements ESI
The Dekabox DC-40 is a two-decade precision capacitance substitution box made by Electro-measurements Inc. (ESI), a U.S. manufacturer known for precision passive component standards. The unit provides a switchable, calibrated capacitance value by means of two large rotary ESI decade dials, allowing the user to set any capacitance within the instrument's range in discrete steps — a fundamental tool for circuit design, alignment, and component testing on the lab bench.
Specifications & What's Included
- Manufacturer: Electro-measurements Inc. (ESI)
- Model: DC-40
- Total Capacitance: 1,111,000 pF (1.111 µF)
- Zero Capacitance: 16 pF
- Maximum Voltage: 400 V DC
- Decades: 2 (two large rotary ESI decade dials, numbered 0–9)
- Terminals: Binding posts (POS/NEG) and dedicated GND terminal on front panel
- Housing: Brown leatherette-covered benchtop enclosure with metal front panel
- Form Factor: Benchtop
- Unit only — no cables or accessories included
Applications
Decade capacitor substitution boxes like the Dekabox DC-40 are standard instruments on electronics lab benches, used wherever a precise, adjustable capacitance value is needed without soldering in individual components. Common applications include resonant circuit design and tuning (LC filter and oscillator work), RC timing network verification, impedance matching and bridge measurements, and component substitution during prototype development and troubleshooting. The ESI Dekabox line dates from the mid-twentieth century and was widely used in university, military, and industrial electronics labs through the 1970s and 1980s. These instruments remain fully serviceable and useful today for any bench technician or engineer working with analog circuits, making them a practical and economical alternative to modern programmable standards.
This Dekabox DC-40 Decade Capacitor by Electro-measurements Inc. has been pulled from a working lab environment and is in good used condition. The housing shows typical age-related wear — the brown leatherette covering has some scuffing and minor creasing consistent with years of bench use. Both ESI decade dials turn smoothly and the markings are legible. The front panel binding posts and GND terminal appear intact. This unit has not been powered up or tested at our facility. Please view our photo set and contact us if you have any questions.
Warranty Information
Additional Information
Brand: |
Electro-measurements Inc. |
Model: |
DC-40 |
MPN: |
DC-40 |
Type: |
Decade Capacitor / Capacitance Substitution Box |
SKU: |
24839 |
Total Capacitance: |
1,111,000 pF (1.111 uF) |
Zero Capacitance: |
16 pF |
Max Voltage: |
400 V DC |
Number of Decades: |
2 |
Dial Type: |
ESI rotary decade dials |
Connector Type: |
Binding posts + GND terminal |
Form Factor: |
Benchtop |
Seller Notes: |
Decade capacitor only — no cables or accessories included. |
Country/Region of Manufacture: |
United States |
Condition Notes: |
This Dekabox DC-40 Decade Capacitor by Electro-measurements Inc. is in good used condition with typical wear on the housing. Not tested at our facility but pulled from a working lab environment. Please contact us with any questions. |
California Prop 65 Warning: |
WARNING: This product can expose you to chemicals including lead and lead compounds, and DEHP (a phthalate), which are known to the State of California to cause cancer and birth defects or other reproductive harm. Go to P65Warnings.ca.gov |
