Repeater (stations) need to idenfiy every 10 minutes while it's on the air. This can be done by the users however, the better way is automatically by the station itself. There are a couple of (old school) manufactors; VHF Engineering and Hamtronics. Both are long gone, since the 1970's however there may be used ones on line. Here's a comparision on the two brands as shown here.
Shown here is the Hamtronics brand in stock form. It will need some additional circuits to work with the System.
Here shown is the 5 v regulator, AF output interface and trip circuits added:
Here shown is the VHF Eng. brand as stock form.
Here shown is the VHF Eng. brand set up for SRG.
Here shown is the interface to work with SRG at one site.