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The 2SC2879 is a high-power NPN RF transistor from Toshiba. This article will discuss the 2SC2879’s key specifications and absolute ratings, pinout and mechanical details, typical characteristic curves and what they mean for amplifier performance, practical applications and more.
The 2SC2879 from Toshiba is a high-power NPN RF transistor designed for communication equipment that requires strong, stable amplification. It operates mainly in the HF band and is known for its excellent gain, linear output, and durability during continuous use. Because of its internal structure and rugged design, it delivers reliable performance even under demanding RF load conditions.
This transistor can provide up to 100W PEP output power, making it widely used in HF radio transmitters, amateur radio linear amplifiers, and similar RF systems. Its TO-220–style flange package helps with efficient heat dissipation, while its wide gain range supports clean and strong signal amplification.
If you are interested in purchasing the 2SC2879, feel free to contact us for pricing and availability.
| Pin Number | Pin Name | Description |
| 1 | Emitter | Main emitter connection for the transistor’s current flow. |
| 2 | Base | Controls the transistor operation and receives the input RF signal. |
| 3 | Emitter | Second emitter connection (common in RF transistors for better grounding and stability). |
| 4 | Collector | Main collector terminal where the amplified RF output is delivered. |
| Model | Type | Output Power (Approx.) | Compatibility |
| 2SC2879A | NPN RF Power Transistor | 100W PEP | Improved/updated version; direct upgrade. |
| MRF455 | NPN RF Transistor | 60–80W | Compatible in many HF amps; slightly lower power. |
| MRF421 | NPN RF Transistor | 80–100W | Good RF linear amplifier replacement. |
| SD1446 | NPN RF Power Transistor | 60–70W | Often used as a plug-in alternative in HF stages. |
| 2SC2290 | NPN RF Power Transistor | 80W | Common substitute; lower output but similar behavior. |
| 2SC3133 | NPN RF Transistor | 60–80W | Can be used in similar HF power amplifier circuits. |
| Parameter | Value |
| Transistor Type | NPN Silicon BJT (RF Power Transistor) |
| Application | HF Band RF Power Amplifier (2–30 MHz), typically 27–28 MHz |
| Output Power (PEP) | 100 W at 12.5 V |
| Power Gain | ~13 dB (typical) |
| Collector Efficiency | ≥ 35% |
| IMD (Intermodulation Distortion) | –24 dB (at 100 W PEP) |
| Collector-Base Voltage (VCBO) | 45 V |
| Collector-Emitter Voltage (VCEO / VCES) | 18 V / 45 V |
| Emitter-Base Voltage (VEBO) | 4 V |
| Collector Current (IC max) | 25 A |
| Collector Power Dissipation (Pc) | 250 W |
| Junction Temperature (Tj max) | 175 °C |
| DC Current Gain (hFE) | 10 – 150 (varies with operating point) |
| Transition Frequency (fT) | ~100 MHz |
| Package / Pinout | TO-247 style; Pin 1 = Base, Pin 2 = Collector, Pin 3 = Emitter |
| Characteristic | Value |
| Collector-Base Voltage (VCBO) | 45 V |
| Collector-Emitter Voltage (VCES) | 45 V |
| Collector-Emitter Voltage (VCEO) | 18 V |
| Emitter-Base Voltage (VEBO) | 4 V |
| Collector Current (IC) | 25 A |
| Collector Power Dissipation (PC) | 250 W |
| Junction Temperature (Tj) | 175 °C |
| Storage Temperature Range (Tstg) | –65 ~ 175 °C |
(Po vs. Pi) shows how the 2SC2879’s output power increases as input drive power is raised. The curve indicates that the transistor delivers strong gain at lower input levels and gradually approaches saturation as the drive increases. This means that at small to moderate input power, the device amplifies efficiently, but as the input approaches the upper limit, the rate of output increase slows. The operating point used for this measurement is around 28 MHz with a 12.5 V supply and an idle current of 100 mA, which reflects typical HF amplifier conditions.
The second graph (IMD vs. Po) illustrates how intermodulation distortion changes with output power. At lower output levels, IMD improves (moves more negative), reaching its best performance around 60–70 W PEP. As the output power climbs closer to the transistor’s full capability, distortion gradually worsens. This behavior is normal for RF power transistors: linearity is best at mid-range power levels, while pushing toward maximum output increases non-linear effects.
• HF (High-Frequency) linear RF power amplifiers
• CB (Citizens Band) radio transmitters and boosters
• Amateur radio (Ham Radio) HF band amplifiers, especially 10–12 meters
• SSB (Single Sideband) linear amplification stages
• Push-pull RF amplifier configurations for high output power
• Replacement or upgrade transistor in legacy RF amplifier equipment
• RF power stages requiring high current and high gain at 28 MHz
• Mobile and base-station communication transmitters
• Hobbyist and commercial RF power amplifier builds and repairs
| Parameter | 2SC2879 | 2SC3240 |
| Transistor Type | NPN RF Power Transistor | NPN RF Power Transistor |
| Intended Use | HF Linear RF Amplifiers (SSB/CW) | HF/VHF RF Power Amplifiers |
| Frequency Range | 2–30 MHz | Up to ~60 MHz (varies by manufacturer) |
| Collector-Emitter Voltage (Vceo) | ~30 V | ~60 V |
| Collector-Base Voltage (Vcbo) | ~45 V | ~80 V |
| Collector Current (Ic max) | 25 A | 30 A (depending on source) |
| Power Dissipation (Pc) | ~250 W | ~300 W (varies by datasheet) |
| Output Power (Typical Use) | ~100 W PEP @ 12.5 V | Higher potential output at higher supply voltage |
| Supply Voltage (Typical) | 12.5 V HF amplifiers | Designed for higher-voltage stages |
| Gain (hFE / Power Gain) | High gain at low voltage (commonly used in CB/ham amps) | Higher gain at higher voltage; often more efficient |
| Package Type | TO-3P / Flanged RF Package | TO-3P / RF Power Package |
| Thermal Resistance | Low (requires good heat sinking) | Lower (better thermal margin in many designs) |
| Biasing | Suited for low-voltage linear class AB | Requires supply voltage consideration |
| Availability | Becoming rare; many clones exist | More modern part; often easier to source |
| Best For | 12–14 V HF linear amplifiers | Higher-voltage RF stages needing more headroom |
| Interchangeability | Direct replacement only with identical voltage conditions | Not a direct drop-in; circuit may need modifications |
| 2SC2879 Advantages | 2SC2879 Limitations |
| High RF power output, suitable for HF/VHF amplification | Discontinued / obsolete; genuine units harder to source |
| Excellent gain and efficiency in amateur radio and CB radio applications | Prone to counterfeits, affecting performance and reliability |
| Robust construction with good thermal handling | Requires proper heat sinking to avoid overheating under high power |
| Stable performance over wide frequency ranges | Not ideal for modern high-efficiency LDMOS-based RF designs |
| Compatible with many legacy RF amplifier circuits | Higher cost due to limited availability |
Toshiba is known for producing high-quality semiconductor components with strong reliability, consistent performance, and advanced manufacturing processes. The company specializes in power devices, RF transistors, discrete components, and integrated circuits designed for industrial, consumer, and communication applications. Its engineering capabilities ensure stable electrical characteristics, efficient thermal management, and long-term durability across a wide range of operating conditions.
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