The 1H5GT is a dry battery diode triode for receiver use. The 1LH4 is the same valve but on a B8B base. In a TRF receiver the diode would provide AM signal demodulation and the high μ triode would be the first audio voltage amplifier.
The Triode at the top and below the central mica sheet is the screen that conceals the rod that acts as the diode anode.
A closer view: the filament tension spring can be seen at the top.
The wide glass tube envelope is 29 mm in diameter, and excluding the IO base pins is 68 mm tall.
References: Data-sheet, 1040 & 1043. Type VT-223 was first introduced in 1939. See also1939 adverts.
