This device is used to couple the aerial to the grid of the detector valve. There is another version of this Met-Vick Resistor Capacitor coupling arrangement that's built into a valve holder - click here to view it.

Met-Vick (Metropolitan Vickers Electrical Company Ltd) used the 'Cosmos' brand name and this is shown on the metal plate of the 'Cosmos Permacon' capacitor.

Download the Met-Vick technical leaflet from the Literature & Info section here that gives a description of Met-Vicks RC coupling units and examples of circuits using them.

The advert shown is taken from Wireless World dated April 24th 1929.