Type 24 / UY-224 Vacuum Tube – Early Screen-Grid Tetrode for 1930s AC Radios

The Type 24 (UY-224) is one of the first AC-powered screen-grid tetrodes, dating to the early 1930s transition away from battery-filament radios.

• Tube type: Screen-grid tetrode
• Base: UY 4-pin (with top cap)
• Heater: 2.5V AC, era-standard for early-1930s AC receivers
• Typical use: RF/IF amplifier stage in early-1930s AC table and console radios

Also cataloged as the 224 tube — same part, era-correct for pre-war radio restorations.