The V241C/1k is a velocity modulated microwave oscillator or Heil Tube it is also marked as CV5049 indicating direct equivalence. The operating frequency is in the range 4.0 - 4.24 GHz.
The construction is detailed in the data-sheet as is the method mounting within the magnet.
The CV5049 printed on the glass. The flange is 31 mm in diameter.
The central copper resonator is connected to the brass flange.
A closer view of the top.
Another close view.
The thin glass tube envelope is 19 mm in diameter, and excluding the B7G base pins is 59 mm tall.
