Look for a rate at least 2.5 to 10 times your bandwidth for accurate waveform representation.
Buying a used oscilloscope can save you hundreds of dollars, but it requires careful testing to ensure you aren't inheriting someone else's "blown front end" or calibration nightmare.
Test all knobs and buttons. Rotary encoders (the knobs on DSOs) are common failure points; ensure they don't skip or lag. buy used oscilloscope
Connect a probe to every channel and attach it to the built-in probe compensation output (usually a small metal tab on the front). You should see a clean, steady square wave.
Check for dead pixels on LCDs or "screen burn" on older analog CRT displays. Top Used Models for Hobbyists (2026) Based on current market availability and community favor: Look for a rate at least 2
This determines the highest frequency signal you can measure. For general hobbyist work, aim for at least 50–100 MHz .
Professional refurbished units from manufacturers like Keysight are calibrated and often come with a warranty. Essential Pre-Purchase Tests Rotary encoders (the knobs on DSOs) are common
When looking for a used unit, prioritize these specifications based on your needs: