Component Testers & LCR Meters

The under-loved bench-drawer instruments. A $20 component tester identifies an unknown SMD passive in seconds; a real LCR meter measures its actual L/C/R/Q/D at frequency. A semiconductor tester sweeps unknown transistors and gives you a curve. Pair with Multimeters for routine measurement, Datasheet & Part Aggregators for what the part should be, and PCB / EDA Suites for footprint sanity-checking.

Universal component testers ("the tweezer-it tester")

• ★ LCR-T7 / TC1 / MTester — the $15–$25 ATmega/STM32-based universal tester. Ident any 2/3-terminal passive or semi (R, L, C, diodes, BJTs, MOSFETs, JFETs, thyristors, IGBTs), measures pinout, gain, threshold. Open-source firmware (Markus Reschke's Transistor Tester); flashable to TC1/T7/T4 hardware. The single best $/utility instrument on a hobby bench.
• DT M328 — older variant of the same project; same firmware.
• Mega328 Tester — generic name for the family; many sellers, identical innards.
• ANENG / Mustool MK328 — pocket clones; same firmware family.

Semiconductor / IV characterization

• ★ Atlas DCA Pro (DCA75) — Peak Atlas's pocket semiconductor analyzer. Identifies device type, pinout, gain, threshold; plus sweeps Vds/Id curves that you can plot on a PC. ~$200. Closed but excellent.
• Atlas LCR45 — pocket LCR meter from Peak; ~$200, frequency selectable.
• Atlas ESR70 / ESR60 — in-circuit ESR / capacitance meters for cap-replacement work.
• Used Tek 576 / 577 — vintage curve tracers; museum pieces but glorious.
• Keithley 2400 / 2450 SMU — see Power Supplies; the "real" curve tracer in 2026 is an SMU and software.

LCR meters

• ★ DE-5000 — the long-time hobbyist LCR favorite. 100 Hz / 120 Hz / 1 kHz / 10 kHz / 100 kHz, with handheld form factor. ~$130 and accurate.
• East Tester ET4410 / ET4502 — bench LCR meters, ~$300; capable, well-spec'd.
• Hioki IM3536 / IM3590 — premium handheld/bench LCR; expensive but immaculate.
• HP / Agilent 4263B / 4284A (used) — eBay lab-grade LCR bridges; calibratable.
• Keysight U1733C / E4980A — Keysight's modern handheld and bench LCR.

Crystal / oscillator testers

• G3UUR / G3JIR crystal-test fixtures — DIY crystal-parameter measurement jigs (motional L/C, ESR, Q).
• Many universal testers identify crystals' approximate frequency.
• A TinySA / NanoVNA plus a Pierce-oscillator jig characterizes crystals well; see Spectrum & VNA.

ESR / cap testers

• Atlas ESR70 / ESR60 — see above.
• Bob Parker ESR meter kits — DIY classic; still a great learning project.
• Many DMMs include capacitance ranges, but few measure ESR — that's the gap these tools fill.

License / pricing notes

• The LCR-T7 / TC1 / M328 family runs open-source firmware ("Transistor Tester" by Markus Reschke and Karl-Heinz Kübbeler) — full source on mikrocontroller.net. You can flash a $10 board with the latest firmware yourself.
• Atlas DCA Pro / LCR45 are closed-firmware; their PC software is free for owners, Windows-only.
• DE-5000 is closed but has a documented IR-USB protocol; FOSS Python loggers exist.
• Hioki / Keysight speak SCPI / proprietary protocols; pyvisa-controllable on the bench models.

Pick this if…

• First component tester, $20 budget: LCR-T7 or TC1. Get one. It's that good.
• Serious semi characterization, pocket form: Atlas DCA Pro.
• Default hobbyist LCR: DE-5000.
• Bench LCR under $400: East Tester ET4410.
• Lab-grade LCR forever: Keysight E4980A or used HP 4284A.
• In-circuit cap fault hunting: Atlas ESR70.
• Curve tracing in 2026: Keithley 2450 SMU + software, not a vintage curve tracer.