Abstract: A system for making emission measurements of RF electromagnetic energy, s as interference, over a relatively wide bandwidth without tuning or scanning and without the knowledge of the specific signal characteristics of the emission under consideration by receiving and detecting the emission in the circuit configuration where the ratio (r) of the impulse signal response to CW signal response is a predetermined function of the pre-detection bandwidth (B.sub.I) and the post-detection bandwidth (B.sub.O). More particularly, the impulse to CW signal response ratio is controlled according to the expression r=1/(2B.sub.O B.sub.I -B.sup.2.sub.O).sup.0.5. Such a relationship will cause the response to all other types of emission to fall intermediate the impulse and CW signal response.