The ARDE from Ediswan was introduced in 1923 as a general purpose valve. The ARDE stands for Amateur Radio Dull Emitter and was advertised as a low temperature valve. Ediswan made three versions of the ARDE. The general purpose without additional paint stripes. The red line for RF and Detector use and the green line for Detector and AF use. These three versions also existed in the earlier AR bright emitter valve.
There are no stripes on this exhibit indicating that it is the general purpose type. The filament was designed to run from a lead-acid accumulator and the filament voltage appears on the brass base cap.
The gettering obscures all internal details on this exhibit but can be seen on ARDE.
The etched lettering and BBC type one stamp are feint and this image has been enhanced to bring up some detail.
Face view - not a good image.
The right hand side. The Ediswan name appears between the BBC stamp and the Type designation.
The wide glass tube envelope is 29 mm in diameter, and excluding the B4 base pins is 94 mm tall.
References: Data-sheet, 1004 & 1003. Type ARDE was first introduced in 1923. See also1923 adverts.
