NONPRECISE PHANTASTRON VARIABLE DELAY

This circuit is designed to delay the start of the cathode ray tube (CRT) sweep for an expanded display. It offers three range settings: 0 to 5 miles, 60 miles, and 200 miles. The circuit primarily utilizes a cathode-coupled phantastron, with additional coupling achieved by returning the suppressor and screen to the same voltage divider. A cathode follower is included to minimize recovery time and provide a low-impedance output for range switching.

The described circuit functions as a timing mechanism for CRT displays, which are commonly used in various electronic applications, including radar and other aeronautical equipment. The phantastron configuration allows for precise control of the timing of the CRT sweep, ensuring that the display remains stable and accurate across different range settings.

The three selectable ranges—0 to 5 miles, 60 miles, and 200 miles—enable the operator to adjust the display according to the specific requirements of the application, enhancing the versatility of the circuit. The cathode-coupled design contributes to the overall stability of the timing signal, while the return of the suppressor and screen to the same divider helps maintain consistent performance across the various operating conditions.

The inclusion of a cathode follower in the design is particularly significant as it serves to reduce the recovery time of the circuit. This aspect is crucial for applications that require rapid changes in display settings, as it allows for quicker transitions between different range settings without introducing lag or distortion in the output signal. Furthermore, the low-impedance output from the cathode follower facilitates efficient range switching, enabling seamless operation in dynamic environments.

Overall, this circuit exemplifies a well-engineered solution for CRT timing applications, balancing precision, speed, and adaptability to meet the demands of advanced electronic systems.Used to delay beginning of crt sweep for expanded display. Provides three ranges: 0 to 5, 60, and 200 miles. Circuit is basically cathode-coupled phantastron, with additional coupling by returning suppressor and screen to same divider. Cathode follower reduces recovery time and provides low-impedance point for range switching. -NBS, "Handbook Prefe rred Circuits Navy Aeronautical Electronic Equipment, " Vol. 1, Electron Tube Circuits, 1963, p N9-3. 🔗 External reference