You're talking away to someone, and before long you notice you're almost to Vincennes and the repeater is sounding a little noisy. Instead of stopping the conversation, all you have to do it change your radio to 146.925, the Vincennes repeater. Then you can talk to your friend on 145.15 by using the repeater closer to you, the 146.925. You can then drive until you run out of range of the Vincennes repeater. By using multiple links, regions of the country can be interconnected for thousands of miles of repeater coverage.
Some links are continous, or full time.
The link is never turned off, except for when an autopatch is in progress. Others may be activated with DTMF tones so that the link can be turned on and off as desired. Repeater control operators are usually the only ones with link DTMF codes. An example of such a part-time link is the 145.45 Petersburg and 147.00 Winslow repeaters. An autopatch is an automatic phone patch.