– Common possibilities include:
The dual-gate construction of the 3SK41 provides distinctive performance dynamics, notably high forward transconductance ( gfsg sub f s end-sub ) and extremely low feedback capacitance. Forward Transconductance ( gfsg sub f s end-sub
The 3SK41 is a depletion‑mode, N‑Channel dual‑gate MOSFET. Unlike a standard MOSFET, it features two electrically independent gate terminals (Gate1 and Gate2) that provide greater flexibility in circuit design, especially for gain control and mixer stages. The four leads (Source, Drain, Gate1, Gate2) are housed in a compact hermetically sealed , a standard for high‑reliability RF transistors of its era.
The 3SK41's unique design makes it ideal for several RF-specific scenarios:
implementation. By varying the voltage on Gate 2, you can control the amplifier's gain without significantly affecting the input impedance or tuning, which is a major advantage in radio receiver design. Censtry.com Sourcing & Replacements 3sk41 datasheet
Acts as an automatic gain control (AGC) node or a shield. It significantly drops the internal reverse transfer capacitance ( Crsscap C sub r s s end-sub
: Ideal for the front end of receivers (pre-amplifiers) due to its low noise figure.
: Minimizes loading on the preceding stage.
If you are a hobbyist, grab a few 3SK41s from surplus stores before they vanish entirely. For new projects, pivot to the BF998 or 3SK299. But for pure vintage authenticity, the 3SK41 remains a small, metal-can legend. The four leads (Source, Drain, Gate1, Gate2) are
A common trick is to take a modern, low‑cost MOSFET and mark it with “3SK41.” A genuine 3SK41 should have a TO‑72 metal can , not a plastic body. It will also have four leads, not three. If a “3SK41” looks like a plastic TO‑92 transistor, it is almost certainly a counterfeit.
: In many circuits, it can be part of a broader series of "3SK" transistors (like the 3SK35 or 3SK40) depending on the specific voltage and gain requirements of your project. Jotrin Electronics Are you looking to use this for a new RF design 3SK41 - NEC/HITACHI/MOTOROLA - Jotrin
): Maximum voltage allowable across the drain and source channels (typically around 10V to 15V). Gate 1-Source Voltage ( VG1Scap V sub cap G 1 cap S end-sub
The is a legendary dual‑gate N‑Channel MOSFET that was a cornerstone of radio frequency (RF) design in the 1970s and 1980s. Produced primarily by NEC and Toshiba , this small but remarkably capable transistor is still revered by vintage radio and amateur‑radio (ham) enthusiasts for its performance in tuners, RF amplifiers, and mixers. As an obsolete device, the 3SK41 remains in high demand for the repair and restoration of classic communications equipment, such as the Kenwood TS‑520S transceiver and Sansui G‑7500 receiver. Censtry
The dual-gate structure of the 3SK41 provides significant advantages in RF signal processing. Why Dual-Gate?
It was a staple in radio frequency (RF) circuits, specifically for VHF/UHF amplifiers and mixers in televisions and FM tuners. Design Advantage:
Finding an original 3SK41 can be challenging outside of specialized "New Old Stock" (NOS) electronics vendors like Jotrin Electronics , UTSOURCE , or LittleDiode. If you need a functional substitute for a repair or layout emulation, look into these common alternative components:
