The 3SK41 is a legacy N-channel dual-gate MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) primarily designed for VHF (Very High Frequency) applications. These components were staples in the design of high-sensitivity radio equipment, particularly as amplifiers and mixers. Because this part is largely discontinued or considered "vintage," finding modern documentation requires looking back at classic semiconductor standards. 🚀 Technical Specifications Overview
The 3SK41 was engineered to provide high gain and low noise figures in high-frequency circuits. Below are the typical electrical characteristics found in the original datasheet. Drain-Source Voltage (Vds): Maximum 20V Drain Current (Id): Maximum 25mA Gate-Source Voltage (Vgs1/Vgs2): ±10V Power Dissipation (Pd): 200mW Forward Transfer Admittance (|yfs|): 10 to 18 mS Input Capacitance (Ciss): ~5.0 pF Noise Figure (NF): ~2.0 dB at 200 MHz 🛠️ Key Features and Advantages
The dual-gate structure of the 3SK41 offers specific advantages that single-gate transistors cannot match easily: 1. Superior AGC Performance
The second gate (Gate 2) is specifically designed for Automatic Gain Control (AGC). By varying the voltage on Gate 2, the gain of the amplifier can be adjusted without significantly shifting the input impedance or frequency response. 2. Low Feedback Capacitance
Dual-gate MOSFETs have very low internal feedback capacitance (Crss). This allows for high-stability amplification at VHF frequencies without the need for complex neutralization circuits. 3. Cross-Modulation Resistance
The 3SK41 is known for its linear transfer characteristics. This reduces the likelihood of "intermodulation distortion," ensuring that strong nearby signals do not drown out the weak signal you are trying to receive. 📐 Pinout and Package Information
The 3SK41 typically comes in a metal-can package (similar to TO-72) with four leads. Proper identification of the leads is critical for circuit stability.
Source: Usually connected to the case/shield to reduce noise. Drain: The output terminal. Gate 2: The control or AGC terminal. Gate 1: The signal input terminal. 📻 Common Applications VHF Tuners: Used in television and FM radio front-ends.
RF Amplifiers: Providing initial signal boost for weak radio waves.
Mixer Stages: Utilizing the two gates to mix the RF signal with a Local Oscillator (LO) signal efficiently.
IF Amplifiers: Standard intermediate frequency amplification in communications receivers. 🔄 Modern Alternatives and Equivalents
Since the 3SK41 is no longer in mass production, hobbyists and repair technicians often look for replacements. While no modern part is a 100% mechanical match, the following are often used in similar circuits: 3SK45: A very close relative often used interchangeably.
BF960 / BF981: Common European dual-gate MOSFETs used for VHF/UHF.
NTE161: A universal replacement part often found in repair catalogs. ⚠️ Usage Considerations
When working with a 3SK41, remember that MOSFETs are highly sensitive to Electrostatic Discharge (ESD). Even a small spark from your fingertip can puncture the thin oxide layer of the gates, destroying the transistor. Always use an anti-static wrist strap and a grounded soldering iron when handling these components.
Understanding the 3SK41: A Comprehensive Guide to the 3SK41 Datasheet
The 3SK41 is a classic N-channel dual-gate MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) that has long been a staple in high-frequency applications. Primarily designed for VHF (Very High Frequency) amplifiers and mixers, it remains a point of interest for hobbyists, vintage radio restorers, and engineers working with legacy RF circuits.
If you are looking for the 3SK41 datasheet specifications, this guide breaks down the essential parameters, pinouts, and application details you need for your project. 1. Overview and Key Features
The 3SK41 is housed in a standard TO-72 metal can package. Its dual-gate construction is its defining feature, allowing for superior gain control and reduced feedback capacitance compared to single-gate FETs. Low Noise Figure: Ideal for front-end RF amplification.
High Power Gain: Provides significant signal boost in the VHF range. 3sk41 datasheet
Dual-Gate Design: Facilitates easy Automatic Gain Control (AGC) and mixing functions.
High Input Impedance: Minimizes loading on preceding stages. 2. Technical Specifications (Absolute Maximum Ratings)
When reviewing the 3SK41 datasheet, the absolute maximum ratings are critical to prevent component failure. Operating beyond these limits can cause permanent damage. Drain-Source Voltage Gate 1-Source Voltage Gate 2-Source Voltage Drain Current Total Power Dissipation Storage Temperature -55 to +150 3. Electrical Characteristics Under typical operating conditions (usually at ), the 3SK41 exhibits the following performance: Forward Transfer Admittance (
): Typically ranges between 10 to 20 mS (millisiemens), indicating high sensitivity. Input Capacitance ( Cisscap C i s s ): Generally around 5.0 pF. Reverse Transfer Capacitance ( Crsscap C r s s
): Extremely low (approx. 0.02 pF), which is vital for stability in high-frequency amplifiers. Noise Figure (NF): Typically 2.0 to 3.0 dB at 200 MHz. 4. Pinout Configuration
The 3SK41 usually follows the standard TO-72 four-lead configuration. Looking from the bottom (pins facing you), the leads are typically arranged as follows:
Source (S) / Shield (Case): Often tied together to provide grounding and shielding. Drain (D): The output lead.
Gate 2 (G2): Typically used for AGC or as the local oscillator input in mixers. Gate 1 (G1): The primary signal input lead.
(Note: Always verify the pinout with the specific manufacturer’s marking, as some variations exist.) 5. Common Applications
The 3SK41 is versatile within the RF spectrum. You will commonly find it used in:
VHF TV Tuners: Used as a low-noise RF amplifier to improve signal reception.
FM Radio Receivers: Acting as the first stage of amplification.
Mixer Circuits: Utilizing Gate 1 for the RF signal and Gate 2 for the Local Oscillator (LO) to produce an Intermediate Frequency (IF).
Signal Generators: Providing stable, high-frequency oscillations. 6. Alternatives and Equivalents
Because the 3SK41 is an older component, it can sometimes be difficult to source. If you cannot find an original, consider these common substitutes: 3SK40: Very similar characteristics, often interchangeable.
BF960 / BF961: Modern silicon N-channel dual-gate MOSFETs (though they often come in SOT packages).
3SK45: A common alternative used in similar VHF applications. Conclusion
The 3SK41 remains a respected component for RF enthusiasts due to its low noise and stable gain. Whether you are repairing a vintage transceiver or building a custom VHF pre-amplifier, understanding the 3SK41 datasheet is the first step toward a successful build. Always ensure proper ESD (Electrostatic Discharge) precautions when handling these MOSFETs, as the gates are highly sensitive to static electricity.
is a specialized N-channel silicon dual-gate MOSFET primarily used for high-frequency applications like VHF/UHF amplifiers and mixers. Often manufactured by companies like The 3SK41 is a legacy N-channel dual-gate MOSFET
, it is known for its ability to handle high-speed switching while maintaining low noise. Jotrin Electronics Key Specifications & Features
The 3SK41 is designed for high-performance RF stages. Below are the typical highlights found in its technical datasheet : N-Channel Dual-Gate MOSFET. : Typically housed in a
(metal can) package, which provides excellent shielding for RF stability. High Gain & Low Noise
: Ideal for front-end receiver stages where sensitivity is critical. Applications VHF/UHF amplifiers.
Balanced mixers (often used in amateur radio equipment modifications to reduce noise and overload). General-purpose high-speed switching. Censtry.com Why the Dual-Gate Design?
The "dual-gate" architecture is what makes the 3SK41 stand out for RF work. The second gate allows for easy Automatic Gain Control (AGC)
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
Because the 3SK41 is an older, often "obsolete" part, it is frequently sought after by hobbyists and engineers for repairing vintage radio gear. AliExpress Where to find : It is still stocked by specialized distributors like Jotrin Electronics Equivalents
: 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
The 3SK41 isn't just a part number; in the world of vintage amateur radio, it’s often remembered as the "silent hero" that cleaned up the airwaves. The Legend of the 3SK41
Back in the late 1970s and early 80s, amateur radio enthusiasts (hams) faced a constant battle with background noise and "front-end overload"—where a strong nearby signal would drown out the faint, distant voices they were trying to catch.
Enter the 3SK41, a high-performance N-channel dual-gate MOSFET. Manufactured by industry giants like NEC, Hitachi, and Motorola, this tiny component became the go-to upgrade for legendary transceivers.
The story goes that when hams swapped out their stock transistors for the 3SK41 in the balanced mixer stage, the change was "amazing". It didn't just boost the signal; it dropped the internal noise floor by as much as 6dB and practically eliminated cross-modulation. Suddenly, the 10-meter band, once a wall of static, became a window to the world. Technical Profile
According to its datasheet specifications, the 3SK41 was engineered for:
High Sensitivity: Improving receiver sensitivity by up to 6dB in some modifications.
Dual-Gate Design: This allowed for better control and gain, making it ideal for RF (radio frequency) amplification. Fast Switching: Its low
RDS(on)cap R sub cap D cap S open paren o n close paren end-sub
made it incredibly efficient for power management in compact designs.
Today, the 3SK41 is considered an obsolete or "hard-to-find" part. For restorers of vintage gear, finding an original 3SK41 in its classic CAN-4 package is like finding a piece of gold—a small, four-legged silicon key to unlocking the pure, quiet reception of radio’s golden age. 3SK41 NEC/HITACHI/MOTOROLA IC Chips | Censtry A misidentified part – Common possibilities include:
is a high-frequency Silicon N-Channel Dual-Gate MOSFET primarily used in VHF amplifier and mixer applications. Manufactured by companies like NEC, Hitachi, and Motorola
, it is a classic component often found in amateur radio equipment and older television tuners. www.jotrin.ru Key Technical Specifications
The 3SK41 is designed for low-noise, high-gain performance at high frequencies. Below are the typical parameters for this device: Drain-Source Voltage ( cap V sub cap D cap S end-sub Drain Current ( cap I sub cap D Power Dissipation ( cap P sub cap D 250mW (0.25W) Package Type: TO-72 (4-lead metal can) Drain-Source On-Resistance ( cap R sub cap D cap S open paren o n close paren end-sub Functional Overview
The dual-gate structure of the 3SK41 allows for several unique circuit advantages: Reduced Feedback Capacitance:
The second gate acts as a shield between the input gate and the drain, significantly reducing Miller effect capacitance. This provides better stability and higher gain at VHF frequencies. Automatic Gain Control (AGC):
By varying the bias on the second gate (Gate 2), the gain of the MOSFET can be controlled without significantly shifting the input impedance of Gate 1. Mixing Applications:
In mixer circuits, the local oscillator signal can be applied to Gate 2 while the RF signal is applied to Gate 1, allowing for efficient frequency conversion with low cross-modulation. Applications & Substitutes Common Uses:
Used in receiver RF amplifiers and balanced mixer stages, particularly in legacy radio gear. Equivalents: If the 3SK41 is unavailable, common substitutes include the 3SK40, 2SK701, 2SK702, and 2SK703 Legacy Availability:
It is currently considered an obsolete or "hard-to-find" part but can still be sourced through specialty electronic distributors like Jotrin Electronics
For a detailed visual of the pinout or specific performance curves, you can find the 3SK41 PDF datasheet on sites like AllDatasheet circuit diagrams
for a specific RF amplifier or mixer design using the 3SK41? 3SK41 Datasheet, PDF - ALLDATASHEET.COM
All. Datasheet. Distributor. Manufacturer. 3SK41. 3SK4. Match, Like. No Data. 3SK40(1) 3SK45(2) Start with. No Data. No Data. End. ALLDATASHEET.COM 3SK41 - NEC/HITACHI/MOTOROLA - Jotrin Electronics
I was unable to locate a specific datasheet for a component labeled "3sk41" in my available technical databases or general search results.
This part number does not match a standard JEDEC, EIAJ, or popular European Pro Electron transistor registration. It could be:
A misidentified part – Common possibilities include:
A generic or house-marked part – Not cross-referenced in public datasheet repositories.
Recommended next steps:
If you meant 3SK41 as a dual-gate MOSFET and can confirm that, I can provide typical characteristics (IDSS, Vgsoff, Yfs, Ciss) based on similar 3SK series devices, but an official manufacturer datasheet is not in my current knowledge base.
When viewing the transistor from below (with the pins pointing toward you and the tab oriented correctly):
Important: 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.
The original 3SK41 datasheet highlights it as an ideal choice for electronic tuners in TVs and VCRs, as well as FM radio front-ends.