Eimac SK-400 Air-System Tube Socket The Eimac SK-400 Air-System Tube Socket is engineered to provide efficient electrical connections and robust mechanical support for power tetrodes, including the 4-400A, 4-250A, and 4-125A tubes. Its design ensures optimal forced-air cooling, effectively managing the thermal requirements of high-power vacuum tubes. Key Features Efficient Cooling Mechanism: The SK-400 features a cast aluminum body that functions as an air duct, directing cooling air through the tube base and around the envelope. This design maintains appropriate operating temperatures and enhances tube longevity. Versatile Compatibility: While specifically recommended for the 4-400A tetrode, the SK-400 is also compatible with other tubes sharing similar physical dimensions, such as the 4-250A and 4-125A. Secure Mechanical Support: The socket provides a firm mechanical foundation for the tube, ensuring stability and reliable performance in various applications. Integrated Air-Chimney Support: For optimal cooling, the SK-400 is designed to be used in conjunction with the SK-406 Air Chimney, which guides airflow over the tube envelope and plate seal. The socket includes provisions for securely mounting the chimney, ensuring efficient thermal management. Installation and Mounting The SK-400 is intended for under-chassis mounting and requires a three-inch diameter hole in the chassis deck. It is secured using four 10-32 machine screws, which also hold clips to fasten the SK-406 Air Chimney in place. This configuration ensures a secure installation and effective cooling performance. Applications Ideal for use in high-power RF amplifiers, transmitters, and other equipment requiring reliable tube performance and efficient cooling, the SK-400 Air-System Tube Socket is a critical component in maintaining the operational integrity of vacuum tube systems.