Repeater "Modules"

D-STAR repeaters can have a number of so-called modules.  Each module is indicated by a letter after the call.  Typically, the letter tells you about the module.  The convention is:

A - 23 cm
B - 70 cm
C - 2 meter
D - 23 cm high-speed data
G - Gateway

These letters actually could be anything, but in practice the only place you see an exception is where a repeater might have multiple modules on one band.

Any useful repeater will have at least a band module and a gateway.  KC8ARJ has a B and a G module.  A surprising number of Michigan repeaters have four, and two have all five.

The letter is the seventh character of the call.  A lot of radios and software have a separate field for the module.  If you are linking to a repeater with a short call, you might have to add spaces.  For example, to link to the 2 meter module of the Battle Creek machine:

    W8DF  CL

That's 2 spaces between the call and the module, forcing the module into position 7 and the command into position 8.

Reflectors also have modules, but in the case of reflectors, the letter has no meaning other than to separate different conversations on the same host. If you look at the three REF024 entries you can see all have the same dashboard and uplink speed (click on the image to enlarge):

And all the modules are combined on the same dashboard: