If you can find an adapter with the same connector that supplies the same voltage and at least the same amperage, you'll be set.
Here are the stats on the base station's AC adapter:
The adapter for a base station (also called a lighthouse) is a 12V AC adapter.
It outputs a max of 2.5A (also called 2500mA).
It uses a 5.5mm x 2.1mm female plug.
It uses an "inner positive" polarity plug.
No problem. Just be sure when looking for adapters that you find an inner positive polarity plug since that's kind of an uncommon configuration for these kinds of adapters. A basic Google search yielded dozens of outer positive polarity plugs, but I didn't find exactly what you're looking for.
Perhaps your determination to find one will result in you doing enough research to find what you're looking for.