A diagnostic apparatus for analysis, testing, inspecting and/or screening an integrated and assembled electrically powered equipment rack and its populated cards and devices for measurement of degree of device aging, improper operation, degradation, condition, and/or Remaining Useful Life (RUL). The device includes an antenna card with a detachably attachable antenna module that can be positioned at a distance from the electrically devices under test and a signal receiver or sensor for examining a signal from the electrically powered device, but especially applied to rackmount supported electronics and/or chassis based electronics. The receiver or sensor collects unintended and/or intended RF energy components emitted by the electrically powered device and performs the above analysis in a response to the acquired signal input while the electrically powered device is active or powered.