Homebrew Test Equipment Calibration
Welcome to the bootstrap calibration lab. This project provides detailed, homebrew calibration procedures for common test equipment without requiring any pre-calibrated reference equipment.
The Bootstrap Calibration Philosophy
"How do you calibrate test equipment when you have no calibrated equipment?"
We use fundamental physical constants and freely available reference signals:
- WWV/WWVH - NIST time signals (2.5, 5, 10, 15, 20 MHz) - frequency accuracy better than 1×10⁻¹²
- GPS 1PPS - GPS satellites provide 1 pulse-per-second timing (±40 ns accuracy)
- AC Mains - Power line frequency (60 Hz in North America, ±0.02 Hz)
- Precision resistors - 0.1% tolerance resistors as voltage/current references
- Crystal oscillators - Can be disciplined against WWV or GPS
- Known physics - Speed of light, resonant frequency calculations
These methods achieve 0.1% - 1% accuracy, which is excellent for amateur radio work and often better than commercial "calibrated" instruments!
Equipment Calibrated
decade resistance box
Complete calibration guide with theory, construction, and procedures.
View Calibration Guide →What You'll Build
The calibration fixtures described in these guides use common, inexpensive components:
Common Materials Needed
| Item | Cost | Source | Used For |
|---|---|---|---|
| GPS Module (NEO-M8N) | $10-15 | Amazon/AliExpress | Frequency reference (1PPS) |
| RTL-SDR Dongle | $20-30 | Amazon | WWV receiver |
| Precision Resistors (0.1%) | $1 each × 5 | Mouser/Digi-Key | Voltage dividers |
| LM4040-10.0 Voltage Ref | $2 | Mouser | 10V precision reference |
| ESP32-2432S028R (CYD) | $12-15 | AliExpress | Display & control |
| Perfboard + Enclosure | $10 | Amazon | Assembly |
| 9V Battery | $2 | Local store | Power |
Total startup cost: $60-85 for a complete calibration lab!
Once built, these fixtures can be used to calibrate all your test equipment, forever. Compare this to professional calibration services that cost $100-500+ per instrument!
Calibration Topics
NanoVNA Calibration
Complete calibration procedures for NanoVNA vector network analyzer including SOLT calibration and building precision cal standards.
View Topic →Oscilloscope Theory
General oscilloscope calibration theory including timebase and vertical gain calibration using WWV and GPS.
View Topic →Multimeter Theory
General multimeter calibration methodology using precision voltage references and calculated resistor networks.
View Topic →LCR Meter Theory
LCR meter calibration using LC resonance calculations and precision components.
View Topic →GPS 1PPS Reference
Building and using GPS 1 pulse-per-second timing reference for frequency calibration.
View Topic →WWV/WWVH Standards
Using NIST time signal stations for precision frequency and time calibration.
View Topic →Construction Guide
General construction techniques for building precision calibration fixtures.
View Topic →Verification Procedures
How to verify calibration accuracy and maintain calibration records.
View Topic →Getting Started
- Read the Overview: Start with Getting Started Guide for a complete introduction
- Choose Equipment: Pick the first instrument you want to calibrate
- Gather Materials: Order precision components (see parts lists in each guide)
- Build Fixtures: Follow construction procedures step-by-step
- Calibrate: Perform calibration procedures and record results
- Verify: Test your newly-calibrated equipment
Quick Stats
1 Equipment Types
Oscilloscopes, multimeters, and LCR meters covered
Complete Documentation
Theory, construction, calibration, and troubleshooting for each
ESP32/CYD Code
Complete Arduino code for Cheap Yellow Display (where applicable)
$60-85 Cost
Build complete calibration lab from scratch
Cost vs. Professional Calibration
DIY Calibration Lab: $60-85 one-time cost, reusable forever
Professional Service: $100-500 per instrument, annual recurring cost
Break-even: After calibrating just 1-2 instruments, your DIY lab has paid for itself!
Bootstrap your way to precision!
73 and happy calibrating - Merv