English: An antique vacuum tube radio receiver made by Atwater Kent in the 1920s. Atwater Kent's radios are distinctive because they didn't conceal the parts in a cabinet but instead mounted the parts on a breadboard where they could be seen. This was an Atwater Kent Type TA detector and 2 stage AF amplifier It was a five tube tuned radio frequency (TRF) receiver, with two stages of tuned radio frequency amplification, a grid-leak detector tube, and two stages of audio amplification. The three dials are the three tuning capacitors. Each had to be tuned separately to a new station, making tuning complicated. The three interstage coupling transformers (grey cylinders) are also visible. The horn loudspeaker (right) is driven by a pair of earphones, a common arrangement in the 1920s which was cheaper than a separate speaker. Exhibit in the Bayernhof Museum, 225 St. Charles Place, O'Hara Township, Pittsburgh, Pennsylvania, USA. Photography was permitted in the museum without restriction.