Scope Probes & Accessories

The probe is half the scope. A 200 MHz scope with a sloppy 60 MHz probe gives you a 60 MHz measurement; a clip-on ground lead can add 50 ns of inductance and turn a fast edge into a ringing mess. Pair with Oscilloscopes, Logic Analyzers, and Spectrum & VNA (whose results are equally probe-limited). For the boards you're probing see PCB / EDA Suites; for ergonomic probing-without-soldering-clips see PCB Tools (PCBite).

Passive probes (the bundled-with-the-scope kind)

• Rigol RP3500A / RP3300A — Rigol's standard 350 / 500 MHz passive probes; bundled with most modern Rigol scopes. Fine for most digital and audio work.
• Siglent PP-510 / PP-2200 / PP-510X — Siglent's standard probes; same tier.
• Tektronix TPP0250 / TPP0500B / TPP1000 — Tek's standard probes; pricier but compatible with non-Tek scopes via BNC.
• Keysight 1054A / N2862B / N2863B — Keysight passives.
• Generic Aliexpress 100 MHz / 200 MHz probes — $10 each; OK for slow signals, terrible for fast edges. Replace the bundled spring-tip ground accessories with a soldered-on short ground spring for any work above ~50 MHz.

Active / differential probes

• Tektronix THDP / IsoVu — high-bandwidth isolated differential probes; THDP0200 (200 MHz, ±750 V differential) is the workhorse. Expensive (~$3k+).
• Keysight N2790A / N2791A / N2818A — Keysight's HV differential probes.
• Rigol RP1000D / RP7150 — Rigol's affordable differential probes; ~$500–$1000.
• Pico Technology TA041 / TA057 — Pico's differential probes; works with any scope (BNC).
• Micsig DP10013 / DP20003 — Chinese low-cost differential probes; the budget pick at ~$300.
• Sapphire / TMI / Cleverscope — niche brands.

Current probes

• Tektronix TCP202 / TCP303 / TCP312A — Hall-effect / Rogowski current probes; the lab standard. Expensive ($1k+).
• Tektronix A622 / A621 — clamp-on AC/DC current probes for general work; ~$500.
• Rigol RP1003C / RP1004C / RP1005C — Rigol's current probes; cheaper.
• Pearson Electronics current monitors — toroidal current transformers; extremely fast, expensive, the right answer for SMPS work.
• Allegro / TI hall-effect-IC-on-a-PCB — DIY current probe builds; fine for low-frequency.
• Hioki CT-series clamp meters — bench/lab clamp meters; pair with a scope's BNC input.

High-voltage probes

• Tektronix P5100 / P5202 / P5210 — 100x and 1000x HV probes for >2 kV work.
• PMK / Hipotronics — niche HV probes.
• B&K Precision PR-50 / PR-100 — affordable HV probes.

Logic-analyzer leads

• ★ Saleae lead kits — colored micro-grippers, the standard with Saleae LAs.
• Pomona / E-Z-Hook minigrabbers — pricier, more durable.
• Generic Aliexpress LA leads — $10 sets that work fine.

BNC / SMA / coax infrastructure

• BNC cables (RG-58, RG-174, RG-316) — the universal scope/AWG/SA interconnect. Buy quality from Pasternack / Mini-Circuits / Amphenol; Aliexpress BNC is OK for low frequency, lossy above ~500 MHz.
• SMA cables — for >1 GHz / RF work. Pasternack / Mini-Circuits / Times Microwave; do not skimp on RF cable. Cable loss specs are usually honest from real vendors.
• SMA torque wrench (8 in-lb) — required for repeatable VNA / SA measurements above ~3 GHz. Pasternack and Mini-Circuits sell calibrated ones for ~$50.
• Adapters: BNC-to-SMA, BNC-to-banana, BNC-tee, 50 Ω terminator, 50→75 Ω matching pad. The "useful adapter drawer" runs to ~$100 of one-time investment.
• Attenuators (3 / 6 / 10 / 20 dB SMA / BNC) — for protecting front ends from overdrive and for impedance-matching.

Probe accessories worth buying

• ★ Short ground springs for passive probes — replaces the long flying-lead ground; reduces ground-loop inductance from ~50 nH to ~5 nH. Required for any edge faster than ~10 ns.
• Probe holders — articulated arms that hold a probe at a test point so your hands stay free. Often called "probe master" or just "third hand for probes."
• Square pin headers — solder a header on a test point for clean BNC-clip access.
• MMCX / U.FL → BNC pigtails — for tapping signals from RF modules.
• Probe deskew fixtures — for matching probe propagation delay across channels (matters above ~200 MHz).

License / pricing notes

• Probe hardware has no firmware (the rare exception: TekProbe / IsoVu, which carry an EEPROM the scope reads to set vertical scale automatically). All probes interoperate via BNC / SMA on the analog side.
• Tek / Keysight / Rigol sell probe accessories at premium. Generic SMA cables and BNC adapters are interchangeable across brands.
• A $300 differential probe isn't as good as a Tek THDP0200, but it's 10x better than no differential probe at all. Buy the Micsig if THDP is out of reach.

Pick this if…

• Bundled probe is fine: for most digital and audio work under 100 MHz.
• Probing fast edges (>100 MHz): add short ground springs to your passives.
• Floating measurement (mains, motor drives): differential probe, full stop.
• Switching power supply current loop: Pearson current transformer or Tek TCP202.
• >1 GHz signal: SMA cables + a torque wrench, not BNC.
• You spend more on adapters than you expected: that's normal; build the drawer.