The RE16 is a WWI German general purpose triode. The design was a copy of the French TM valve but was less efficient. These valves were used in both trench sets and aircraft radios.
In the early 1920's with the start of broadcasting the surplus R Types were in great demand and many survive, but the German copies, being less effective, largely faded from history and few survive.
This exhibit is dated 1918.
The anode and grid are made from copper. The filament is a single tungsten strand. This filament looks intact but in fact is broken in the centre. The construction by Telefunken is more refined than the RJW from Seddig.
A closer view with the focus point on the filament termination.
This view has the focus point on the grid loops. In fact the grid has been stamped from a sheet of copper and bent into a cylinder. The tab at the near end closes the two ends together.
Here the grid can be seen to be made of thin strips and not wire.
When looking straight on to the side of the anode the grid strips and fixing tabs are clearly seen. The anode is a strip of copper bent into a cylinder with the fixing being the final part of the sheet formed round the support wire and it looks to be soldered into place.
The anode fixing to the support wires.
The base pins are of two part construction. The split copper sleeve is pushed over a brass pin. The anode is a plain hollow cylinder. Was the red paint on the dome to indicate the Type or to act as an indication that the filament was working?
The paper label around the base shell.
The feint etched lettering on the glass revealed. The serial number is 13402/3 where the /3 indicates the filament current as 0.53 Amp.
The Telefunken valves were designed to operate at a specific filament current - established on test at the factory and indicated on the glass by the final digit of the serial number. To run the valve at this specific current an iron wire resistor (Barretter) was supplied with the valve. Our exhibit does not have the resistor and this image is from the Internet.
The wide glass tube envelope is 42 mm in diameter and, excluding the base pins, is 97 mm tall.
References: 1047, 3002 & G3YNH. Type RE16 was first introduced in 1917.