Abstract: An adapter including a front and rear conductive portion separated by a filter device and a non-conductive support, through which an RF-type cable connector can be inserted and mounted on a receiving connector on an external device. Because the conductive portions of the adapter are isolated from the panel by means of the disc capacitor, all DC ground currents are prevented from passing through the filtering device, effectively isolating the shell of the panel on which it is mounted, while all AC currents are passed through the filtering device to the panel on which it is mounted, effectively grounding any undesired radiating signals and preventing interference. The adapter can be supplied as a single unit which is simply inserted over the connector body before panel mounting.