I found this in the 'East End News & London Shipping Chronicle' dated 3rd September 1937:
“RADIOLYMPIA Latest Models & Inventions - Mikes Radio are showing an unassuming piece of apparatus that has a crowd round it all day. It is the beginning of what will one day be the all-(gas)-mains radio set. Connect one of these instruments to a gas pipe, and charge your own accumulators. Electricity is generated from metals which are at present secret and which are heated by tiny gas-jets.”
Details
Location
Mikes Radio/Mrs Miller Newport Court Soho / London
“RADIOLYMPIA Latest Models & Inventions - Mikes Radio are showing an unassuming piece of apparatus that has a crowd round it all day. It is the beginning of what will one day be the all-(gas)-mains radio set. Connect one of these instruments to a gas pipe, and charge your own accumulators. Electricity is generated from metals which are at present secret and which are heated by tiny gas-jets.”