Datasheet: 3sk41

Thanks to a low on-resistance (

If you are looking for or CAD models , I can suggest specialized distributors.

): Extremely low (approx. 0.02 pF), which is vital for stability in high-frequency amplifiers. Typically 2.0 to 3.0 dB at 200 MHz. 4. Pinout Configuration

): Typically ranges between 10 to 20 mS (millisiemens), indicating high sensitivity. Generally around 5.0 pF. Reverse Transfer Capacitance ( Crsscap C r s s 3sk41 datasheet

| Equivalent / Replacement | Type / Package | Key Considerations & Guidance | | :--- | :--- | :--- | | | N-Channel Dual-Gate MOSFET | Common TV tuner ICs; pinout differs, may require board modification; BF998 offers superior noise figure | | 3N201, 3N211 | N-Channel Dual-Gate MOSFET | Popular, common replacements in vintage gear; verify pinout and adapt if necessary | | 3SK40, 3SK45, 3SK48 | N-Channel Dual-Gate MOSFET | Near-identical specs; some tuner servicing guides report success with direct substitution of 3SK48 for 3SK41 | | NTE454 | N-Channel Dual-Gate MOSFET | Modern universal replacement; widely available, but confirm pin compatibility before use | | KP382A (Russian) | N-Channel Dual-Gate MOSFET | Potential replacement from Russian electronics; verify pin configuration matches your circuit |

The is a classic, high-performance N-channel dual-gate Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) manufactured by prominent semiconductor pioneers such as NEC , Hitachi, and Motorola. Primarily packaged in a hermetically sealed metal TO-72 (CAN-4) enclosure , this device is legendary in legacy RF (Radio Frequency) engineering for its high switching speeds, exceptionally low power dissipation, and outstanding noise-performance balance.

In the 1970s and 80s, components like the 3SK41 were the "brain" behind the clear signal reception of color televisions and high-fidelity FM radios. Obsolescence: Thanks to a low on-resistance ( If you

By shifting the AGC bias voltage on Gate 2, engineers can dynamically control the amplifier's gain across a wide dynamic range without shifting the input impedance of Gate 1. This keeps the receiver's tuned circuits from detuning as the signal strength fluctuates.

The 3SK41 datasheet highlights several critical parameters that make it suitable for VHF and UHF amplification. 20V (Maximum) Gate-Source Voltage (Vgs): 7V (Maximum) Drain Current (Id): 25mA Power Dissipation (Pd): 250mW Forward Transfer Admittance (gfs): 8.0mS (Minimum) Input Capacitance (Ciss): 5.0pF (Maximum) Case Type: CAN-4 or TO-72 (4-lead metal package) Key Features & Applications

Standard single-gate MOSFETs suffer from the , where internal parasitic capacitance between the drain and gate amplifies feedback, causing instability and self-oscillation at radio frequencies. Typically 2

A highly accessible, surface-mount (SOT-143) N-channel dual-gate MOSFET offering high transconductance and low noise. It is widely used to replace vintage through-hole RF FETs.

TO-72 / CAN-4 Pinout (Bottom View) (Case/Shield) [Pin 4] (Gate 2) o o (Gate 1) [Pin 3] [Pin 1] o o (Drain) (Source) [Pin 2] [Pin 5 / Tab]