The Evergreen Intertie is an interconnected group of amateur radio repeaters located in the Northwestern United States. FM repeaters operating in the VHF and UHF bands are interconnected (linked) by full duplex UHF radios. The network is open to all licensed amateurs, and access codes are available.
The Evergreen Intertie is a repeater linking system with a mixture of various connections and equipment types. In general, repeaters which make up the system can be operated independently or they can be switched onto common communication trunks or party lines. A repeater that is switched onto a trunk line can communicate with any other repeater that also happens to be connected to the same trunk. There are a number of different and independent trunk lines that make up the Evergreen Intertie. Normally these trunk lines are separated by "Intertie" switches which allow repeaters on one trunk to communicate without interfering with a simultaneous conversation among repeaters on another trunk. If the Intertie switch were closed i.e. switched to the "on" position then all listeners on both trunks could participate in a single conversation. The more trunk lines that are tied together the more potential listeners there might be, but still only one person can talk or transmit at a time per trunk or per group of intertied trunks. To establish the various repeater link connections users of the system must send commands to an Intertie controller commanding it to add or drop repeaters from the Intertie, turn on or off Intertie switches or to interrogate the current switch positions for a specific Intertie link controller.