I can help narrow down the exact matching pinouts or source further pin configuration schematics. Share public link
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.
Leveraged in legacy high-speed switching loops where rapid, low-resistance transitions are necessary. Thermal Management & Handling Constraints
). For the 3SK41, this sits around 10 to 18 mS (millisiemens). High transconductance directly correlates to the high gain capability of the FET. Input Capacitance ( Cisscap C sub i s s end-sub
) allows separate bias control. Users can feed a DC control voltage into G2cap G sub 2 to smoothly scale the transconductance ( gfsg sub f s end-sub
This circuit is ideal for FM radio (88-108 MHz) or aircraft band (118-136 MHz).
Specialists like RF Parts Company maintain inventories of original active components for older communication gear.
Do you prefer components, or are surface-mount (SMD) alternatives acceptable?
Before designing any circuit, you must respect the limits listed below. Exceeding these values will destroy the MOSFET, as it is extremely static-sensitive.
VG1S(off)cap V sub cap G 1 cap S open paren o f f close paren end-sub
The 3SK41 is designed for superior performance in VHF/UHF applications. Its dual-gate structure allows for versatile gain control, which is essential for automatic gain control (AGC) in receivers.
| Part Number | Compatibility Notes | Availability | | :--- | :--- | :--- | | | Nearly identical pinout (SOT-103). Superior noise figure (2dB). Drop-in with adapter. | Scarce | | BF998 | Surface mount (SOT-143). Higher transconductance. Requires a breakout board. | Common | | 3SK74 | Direct Japanese equivalent. Same TO-72 package. Perfect for vintage restorations. | Rare | | MPF121 | American equivalent, but higher capacitance. Not ideal above 150 MHz. | Obsolete | | Dual-gate 40673 | Metal can. Higher VDS tolerance but lower gain. Works as a slow substitute. | Obsolete |
3sk41 Datasheet Jun 2026
I can help narrow down the exact matching pinouts or source further pin configuration schematics. Share public link
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.
Leveraged in legacy high-speed switching loops where rapid, low-resistance transitions are necessary. Thermal Management & Handling Constraints
). For the 3SK41, this sits around 10 to 18 mS (millisiemens). High transconductance directly correlates to the high gain capability of the FET. Input Capacitance ( Cisscap C sub i s s end-sub 3sk41 datasheet
) allows separate bias control. Users can feed a DC control voltage into G2cap G sub 2 to smoothly scale the transconductance ( gfsg sub f s end-sub
This circuit is ideal for FM radio (88-108 MHz) or aircraft band (118-136 MHz).
Specialists like RF Parts Company maintain inventories of original active components for older communication gear. I can help narrow down the exact matching
Do you prefer components, or are surface-mount (SMD) alternatives acceptable?
Before designing any circuit, you must respect the limits listed below. Exceeding these values will destroy the MOSFET, as it is extremely static-sensitive.
VG1S(off)cap V sub cap G 1 cap S open paren o f f close paren end-sub Leveraged in legacy high-speed switching loops where rapid,
The 3SK41 is designed for superior performance in VHF/UHF applications. Its dual-gate structure allows for versatile gain control, which is essential for automatic gain control (AGC) in receivers.
| Part Number | Compatibility Notes | Availability | | :--- | :--- | :--- | | | Nearly identical pinout (SOT-103). Superior noise figure (2dB). Drop-in with adapter. | Scarce | | BF998 | Surface mount (SOT-143). Higher transconductance. Requires a breakout board. | Common | | 3SK74 | Direct Japanese equivalent. Same TO-72 package. Perfect for vintage restorations. | Rare | | MPF121 | American equivalent, but higher capacitance. Not ideal above 150 MHz. | Obsolete | | Dual-gate 40673 | Metal can. Higher VDS tolerance but lower gain. Works as a slow substitute. | Obsolete |