... Jade morton (now at colorado state) brought a novatel multi frequency gps receiver to ao. ... The cpu will be placed in the antenna test shack while the active antenna will be on the roof of the shack. ... An rf cable out to the 904 antenna probe . ... the red lines show the 10 sweep peak hold. 904 probe at the antenna (.pdf) . 904 probe at the front of the cpu (.pdf) . 904 probe at the back of the cpu (.pdf) . 904 probe with antenna, cpu off (.pdf) . ... near 425 Mhz . ...