This YL1130 was made in Holland by Philips. The YL1130 is a quick heating double beam tetrode output valve for mobile communications use. The frequency limit of 500 MHz makes this ideal for VHF and low UHF use.
The normal operating conditions would have 175 V on the anodes and 175 V on the common screen grid.
The grey sheet is one anode seen face view. In cross section it is a flat bottomed U. The bright electrodes either side are the beam plates.
This image shows the wire filaments, the two control grids, common screen grid and outer beam plates.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins is 64 mm tall.
Reference: Datasheet. Type YL1130 was first introduced in 1966.