154-0644-00
The Tektronix 154-0644-xx is a cathode-ray tube. Suffix -05 has green P-31 phosphor, suffix -09 has blue P-11 phosphor.
It has distributed deflection plates and is used in instruments specified up to 500 MHz.
Typical acceleration voltage is 24 kV (-3 kV on cathode, -+ 21 kV on anode).