The advent of radio as a home entertainment medium in the early 1920s presented Victor and the entire record industry with new challenges. Not only was music becoming available over the air free of charge, but a live broadcast made using a high-quality microphone and heard over a high-quality receiver provided clearer, more "natural" sound than a contemporary record. In 1925, Victor switched from the acoustical or mechanical method of recording to the new microphone-based electrical system developed by Western Electric. Victor called its version of the improved fidelity recording process "Orthophonic", and sold a new line of record players, called "Orthophonic Victrolas", scientifically designed to play these improved records. Victor's first electrical recordings were made and issued in the spring of 1925. However, in order to create sufficient catalogs of them to satisfy anticipated demand, and to allow dealers time to liquidate their stocks of acoustical recordings, Victor and its rival, Columbia, agreed to keep secret from the public, until near the end of 1925, the fact that they were making the new electrical recordings which offered a vast improvement over the ones currently available. Then, with a large advertising campaign, Victor openly announced the new technology and introduced its Orthophonic Victrolas on "Victor Day", November 2, 1925.