The general concept of SBAS has a number of channels available and I would expect the WAAS navigator to search through these at power-up. For example when you buy an IFD540, and install it in the US, or install it in the UK, is there a country-specific config? Looking in the IFD540 IM: No other mention of SBAS or any kind of country setting, and it would be daft because you would not be able...