Well well, if I were to ask you to name the most famous inventors in the world of communications, who would you include? James Clerk Maxwell for his equations, Heinrich Rudolf Hertz for his demonstration of electromagnetic waves, or Guglielmo Marconi for his engineering to turn theory into practice and build the earliest working radio systems?

Here we have the Marconi RS-4 as we found it, missing a couple of knobs and looking well used.

Here it is with the case off, showing that the interior chassis paint seems quite good condition.

Here is the view inside the case, showing some dust and dirt however all the valves are in place and undamaged.

Here is a close-up of the tuning capacitor rack, showing a little surface corrosion but otherwise ok. The tuning dial still moves as well!

Here is a close-up of the RF section valves, showing a mix of Osram and Marconi brands. Most likely some have been replaced in service.

Inside the case we found a rather damp but intact circuit diagram!

The model label clearly shows the Type and a Serial number, along with the company name of Marconi Wireless Telegram Co. Ltd. London. Also an 'Instrument No'.

The radio is now in the Marconi Collection. More information here about the collection