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: buy used oscilloscope
This determines the highest frequency signal you can measure. For general hobbyist work, aim for at least 50–100 MHz . Connect a probe to every channel and attach
Deeper memory allows you to capture longer time windows while maintaining a high sample rate, which is crucial for finding intermittent glitches. Top Used Models for Hobbyists (2026) Based on
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.
Professional refurbished units from manufacturers like Keysight are calibrated and often come with a warranty. Essential Pre-Purchase Tests
When looking for a used unit, prioritize these specifications based on your needs: