Signal Co. in 1932, when it was bought by a Buffalo, New York company, Deck Brothers, working under contract for the United States Lighthouse Service. This company still exists, although it no longer manufactures diaphones. The European manufacturing rights were obtained by Chance Brothers of Birmingham in the United Kingdom, already a major supplier of Fresnel lenses and other equipment to lighthouse authorities. In use, the diaphone was generally found to be reliable and suffered little from wear, as the lightweight piston floated on a cushion of air during oscillation. Such wear as did occur tended to happen as a result of the piston becoming loose: as the pistons were custom-made and the design to some degree affected the individual sound characteristics of the signal, the manufacturers supplied two spare pistons with each diaphone. The majority of diaphone installations were removed or became disused during the 1960s and 1970s. This was partly a result of automation of lighthouses, but it was also found that modern diaphragm horns would produce similar levels of volume to a diaphone while requiring much smaller and less powerful compressors. By 1983, the last two-tone "F2T" type in full-time operation in the United States was at Edgartown, Martha's Vineyard. A few survive in working condition in lighthouses around the world. The Gamewell diaphone This considerably smaller device was produced by the Gamewell Corporation, of Newton, Massachusetts, for use as a municipal alarm, especially at fire stations, to alert firefighters and the public during emergencies. Many Gamewell diaphone systems remain in use today. The Gamewell diaphone has a range of about six miles () under optimum conditions. Working diaphone installations The following installations are still functional and are demonstrated from time to time as tourist attractions. Detour Reef Lighthouse near Detour, Michigan restored their original Type F2T diaphones to working condition and reinstalled them in the lighthouse, complete with new compressors and air tanks. East Brother Island Light, Richmond, California has a fully restored fog signal building with operational 2-tone Type F2T diaphones. Grand Traverse Light, Michigan has a working Type CC diaphone. Nantucket Light Ship museum in Boston, Massachusetts sounded its restored diaphone for the first time on August 7, 2015. Nash Point Lighthouse, South Wales, United Kingdom Portland Bill Lighthouse, Isle of Portland, United Kingdom: A Type F diaphone decommissioned in 1996, but restored in 2003 for the benefit of visitors. Low Head Lighthouse in