Eee PC SMPSU noise

One disadvantage to using the Eee PC as an WSPR station - apart from the flakiness of its Linux OS - is that its power supply is a switched mode wall wart of the worst sort, a wideband noise and wandering warble generator. It's made in China and is rated at 9.15V 2.3A output. I don't suppose it will be easy to find a noise free alternative.