The Teledyne LeCroy D420 / 3224 kit is a 4 GHz differential probe solution built around the D420 ProBus2 probe amplifier (4 GHz bandwidth) and the DX20 family of interchangeable tips (solder‑in, quick‑connect, square‑pin), supplied as a matched probe kit for high‑speed differential measurements.
The D420 is a 4 GHz ProBus2 differential probe amplifier designed for Teledyne LeCroy’s WaveLink/ProBus2 probe ecosystem; it provides the active front‑end, gain settings, and compensation that, together with matched tips, deliver accurate differential measurements up to 4 GHz. The kit form (often sold as D420 / 3224 or D420‑A‑PB2) bundles the amplifier with a set of DX20 tip options to cover solder‑in, quick‑connect, and square‑pin terminations for flexible lab use.
The kit typically includes Dx20‑SI (solder‑in), Dx20‑QC (quick‑connect), and Dx20‑SP (square‑pin) tip assemblies so you can switch terminations without changing the amplifier; tips are precision mechanical parts that control lead length and impedance to maintain the 4 GHz response. The ProBus2 interface and WaveLink system ensure the probe identifies to the oscilloscope and applies the correct compensation/correction data when supported by the scope.
A standard D420 / 3224 kit listing shows the D420 probe amplifier plus one each of Dx20‑SI, Dx20‑QC, and Dx20‑SP tip assemblies and associated mounting hardware; vendors may sell additional tip packs or calibration services separately. Calibration and periodic verification are recommended; service vendors list calibration and repair options for the D420 amplifier to maintain specified performance.