This power triode exhibit has lost all markings. It is the same envelope size as the QY4-250 but has a large graphite anode with eight side wings for greater radiating area. The anode dissipation will be a minimum of 250 Watts and probably much higher.
The anode core with side flanges.
The B5F base pins set in a sintered glass base for extra strength.
The cage grid and within the thoriated tungsten filament is a double helix. A central post holds the top of the filament.
The special finned top cap.
The screw fixing at the top for the lead and side screw to fix to the top cap.
looking into the top cap.
The B5F unused ceramic base.
The underside of the base. The markings on the ceramic are not for this triode.The wide glass tube envelope is 85 mm in diameter, and excluding the B5F base pins is 128 mm tall.Reference: Observation. |
Updated March 28, 2025.
|
|
