Abstract: A probe interface device is disclosed that includes a plurality of coaxial contact probe assemblies disposed in an insulative base. Each coaxial contact probe assembly includes a solid tubular shield with a coaxial signal contact probe, which is isolated from the shield by an insulative retainer; and, a solid tubular reference with another coaxial contact probe. The shield and the reference are soldered together at their respective ends. Further, the insulative base includes an upper retainer and a lower retainer attached to a hollow frame. The upper and lower retainers are provided with the same number of holes for engaging a plurality of coaxial contact probe assemblies. The probe interface device can be used for testing mixed-signal devices and is easy to manufacture.