The DEL610 is a 1928 directly heated triode that was designed for use as a detector or audio voltage amplifier.
There also existed a two volt DEL210 and a four volt DEL410 both from 1927.
The lettering on the dome is very feint but on the side are etched the words Marconi Valve.
With difficulty the Type designation can be seen on the dome.
The electrode assembly is mounted horizontally. One loop of the filament can be seen as well as the grid that extends slightly beyond the edge of the anode box.
The balloon envelope is 45 mm in diameter, and excluding the B4 base pins is 83 mm tall.
Reference: 1043. Type DEL610 was first introduced in 1927. See also1927 adverts.
