Repeater ATV operation requires specially-equipped repeaters. The club manages several public repeaters that reach around Worcester such as the Higgins Repeater. An Ethernet repeater with multiple ports is known as an Ethernet hub. Somewhat larger networks can be built by using an Ethernet repeater. The channels are commonly grouped into repeater inputs, simplex, and repeater output frequencies. European Accords now included a side turn signal repeater just behind each front wheel well. An extensive digital repeater, or "digipeater," network provides transport for APRS packets on these frequencies. Black was working on reducing distortion in repeater amplifiers used for telephone transmission. This is a type of telephone repeater used in underwater submarine telecommunications cables. In order to run the repeater a repeater controller is necessary. Installing a home cellular repeater may remedy this. An electrical repeater, or synchro, was added to the gonio dial. Additional features include APRS object representation of each repeater. The majority of the repeater components are passive. Other more expensive complications include Tourbillon, Perpetual calendar, Minute repeater, and Equation of time.