The 3SK41 is a dual-gate N-channel MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) that was once a staple in VHF and UHF applications. While modern components have largely replaced it, understanding its datasheet is crucial for replacement, reverse-engineering, or educational purposes.

Many listings on eBay or Aliexpress selling "3SK41" are actually remarked BF245 or 2N5486 JFETs. If the pinout measures like a diode (P-N junction), it is a fake. A real 3SK41 will measure open circuit between all pins when tested with a multimeter's diode setting (except source-to-drain when body diode conducts).

A solid, classic dual-gate MOSFET datasheet. It provides all the essential DC and RF parameters needed for VHF/UHF design, though users should be aware of its age and the potential lack of modern application notes.

Converting high-frequency signals to intermediate frequencies (IF). Oscillators: Found in Colpitts and Hartley RF oscillator designs. Cross-Reference & Equivalents