3sk41 Datasheet File
Its dual-gate design allows for efficient automatic gain control (AGC) or local oscillator injection without compromising stability. Sourcing & Replacements
| 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 |
A common alternative used in similar VHF applications. Conclusion
): Provides high power gain (typically 15 dB to 20 dB depending on frequency and biasing), which ensures weak incoming signals are boosted efficiently. Input and Output Capacitance ( Cisscap C sub i s s end-sub Cosscap C sub o s s end-sub 3sk41 datasheet
If you are looking for or CAD models , I can suggest specialized distributors.
Historical datasheets provided two classic topologies: and AGC-controlled IF Amplifier .
: Don't rely solely on large, generic parts distributors. Specialized vendors like RF Parts Company or CEI Distribution are often a better bet for obsolete RF transistors. Hobbyist-focused electronics suppliers, such as Nikko Electronics , also stock these components, typically priced around £12.99 per unit. Its dual-gate design allows for efficient automatic gain
Ideal for RF amplifiers, mixers, and Automatic Gain Control (AGC) circuits in radio receivers.
The metal case is sometimes internally connected to the source (Pin 1) or left floating. Check the specific manufacturer's datasheet; if grounded, it provides shielding.
Standard range (e.g., up to 125°C or higher for metal cans) Feature Look-In: The Dual-Gate Advantage The defining characteristic of the 3SK41 is its Drop-in with adapter
Looking at the top or bottom of the device package (refer to your specific datasheet graphic for orientation), the four leads correspond to:
The 3SK41’s four leads can be confusing for those who are accustomed to three‑terminal transistors. The typical pinout is:
The 3SK41 is a Silicon N-Channel Dual-Gate Metal Oxide Semiconductor Field-Effect Transistor (MOSFET) housed typically in a or CAN-4 package.
The 3SK41 remains a powerful, reliable choice for high-frequency RF amplification in legacy or specialized equipment. Its ability to provide low-noise amplification, combined with easy AGC control via its dual-gate design, makes it a noteworthy component in the history of communication electronics. When repairing or designing older RF circuits, the 3SK41 (or its modern equivalents) is an excellent component to consider.