Dear ACW342, Blick, and WeatherCat station caregivers,
To avoid this almost biennial meeting, does anyone know of a way to connect a 3V DC supply to the unit without frying the internals?
Indeed Davis technical support will know the definite answer, but odds are that you can. I've been powering my Davis Vantage Pro-2 from home AC for years now. Here is a photo of the ISS circuit board with the required connections:
Here is a photo of the exterior arrangement:
This allows me to keep the temperature and humidity probe under a large deck that all but eliminates problems of solar radiation perturbing the air temperature values.
I can't be sure the Vantage Vue is the same because they must have done some cost-cutting measures. However, if the ISS circuit board is the same, then certainly you will be able to power your station with AC power.
Cheers, Edouard