A repeater takes a received signal and re-transmits it on a different frequency known as the "offset" frequency. Amateur radio enthusiasts use repeaters to establish contact over a larger distance than would normally be possible, especially when operating mobile from a car or with a low power handheld radio. Repeaters are positioned on strategic sites chosen for their height, giving a "line of sight" view to the area that they cover and thereby allowing low power devices to communicate through them. For this reason in cities repeaters are often situated on the roof of high-rise buildings, and in rural locations on hilltops. Amateur repeaters are run out of a dedication to the hobby and not for any commercial gain. They generally use donated equipment and rely on financial donations to cover overheads such as rent. This category contains sites that are specific to particular repeaters in the United Kingdom and generally will contain details about their construction, operating frequencie- Category ID : 165793