The CV10804 (commercially the D3a) is a special quality frame grid pentode for wideband amplification. The mutual conductance is very high at 35 mA/V.
The D3a commercial Type designation.
The cathode is a flattened tube. The beam plates are mounted either side between the centre and the two anode plates. In the middle can be seen the double sided screen grid.
With the microscope the beam plate opening is at the top with screen grid and ultra fine control grid winding lower down. At the very top is the reflection of the screen grid on the polished beam plate.
Maximum magnification.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins is 55 mm tall.
Reference: Data-sheet. Type CV10804 was first introduced in 1958. See also1958 adverts.
