Effects of environmental testing on the surface transfer impedance/EMP response of cable assemblies with metal banded braid terminations

The surface transfer impedance and electromagnetic pulse (EMP) response of two sets of samples were measured before and after a series of environmental tests. Each sample consisted of 1 m of multiconductor cable terminated to a backshell which in turn was mounted on a MIL-C-81511 connector. The surface transfer impedance and the EMP response were measured using the procedures of MIL-C-24640 and MIL-C-85485A, modified to accommodate cable assemblies rather than samples of cables. Samples that used a metal band method of braid termination and samples that used a Metcal solder strap braid termination were evaluated and compared. The effects that mechanical and thermal environmental testing had on the integrity of the electromagnetic shielding are described. This testing was meant to simulate the adverse treatment that an interconnect system might receive during its lifetime. The results of the measurements are presented