The **2JS6-R** is a specific electronic component, primarily categorized as a **vacuum tube** (thermionic valve). Historically, it was used extensively in the horizontal deflection circuits of color television sets and is now a popular choice for radio frequency (RF) power amplifiers in amateur radio equipment. --- ## 1. Technical Specifications The 2JS6-R is a **Beam Power Pentode**. It is designed to handle high voltages and provide significant power amplification. | Parameter | Specification (Typical) | | :--- | :--- | | **Tube Type** | Beam Power Pentode | | **Filament/Heater Voltage** | 6.3 Volts | | **Heater Current** | 2.25 Amperes | | **Max Plate Dissipation** | 30 Watts | | **Max Plate Voltage (DC)** | 990 Volts | | **Base Type** | Novar (9-pin) | --- ## 2. Key Internal Parts As a vacuum tube, the 2JS6-R consists of several internal electrodes housed in a glass envelope: 1. **Heater (Filament):** Glows red to heat the cathode. 2. **Cathode:** Coated with materials that emit electrons when heated. 3. **Control Grid (G1):** Regulates the flow of electrons from the cathode. 4. **Screen Grid (G2):** Accelerates electrons toward the plate and reduces capacitance. 5. **Suppressor Grid/Beam Plates:** Directs the electron beam and prevents "secondary emission" (electrons bouncing back). 6. **Anode (Plate):** The large outer metal structure that collects electrons, generating the output signal. --- ## 3. Common Applications While originally mass-produced for televisions, the 2JS6-R is now known for: * **HF Transceivers:** Used in the "Final" power amplifier stage of vintage radios (e.g., Yaesu FT-101 series). * **RF Power Amplifiers:** Capable of producing high output power in the HF (High Frequency) bands. * **Audio Amplifiers:** Occasionally used by hobbyists for high-power tube audio projects, though less common than the 6L6 or EL34. --- ## 4. Maintenance and Replacement * **Matching:** If used in a "push-pull" or parallel configuration (like in an FT-101), tubes should be **matched pairs** to ensure equal workload. * **Neutralization:** When replacing these tubes in a radio, a "Neutralization" procedure is often required to prevent the tube from oscillating and burning out. * **Heat:** Due to the high heater current (2.25A), these tubes generate significant heat and require proper ventilation. ---