BG Micro has some nice 48V 2A power supply modules for around $12. IEC power cord in (100-240V), 2.1mm barrel connector out. Seems to work well with my Nortel GPSDOs, but I haven't scoped the thing out for noise, etc. http://www.bgmicro.com/48v-2-08a-enclosed-power-supply-by-xp-power-2-5mm-right-angle-barrel-connector.aspx