These racks formed the mainstay of many of the wide area police and fire schemes from the early 1970’s onwards using VHF links in the 146/154 MHz band back to control or via a repeater site.
This picture shows two racks, each containing identical duplicated (main/standby) equipment for resilience to support two police channels
Left Rack - CH2
Right Rack - CH1
the two 10 watt Link Tx’s (to control), next two units are the Link Receivers (from control) followed by the two mobile receivers.
"Top of the rack is a Home Office produced Site Alarm and Generator alarm. If I recall entry to site produced a 3 KHz tone which captured ASSORT. Generator running produced a Beep at HQ."
Picture Source & Copyright:
South Yorkshire Police c1982