A self-guiding cover assembly for a vacuum electron device (VED) enclosure (704, 1316) has a cover (1002, 1302), a pair of guide plates, and a pair of guide elements (1304, 1306). The cover has at least one electrical connector (1314) disposed on the inside thereof for mating with a VED. The pair of guide plates is disposed on opposite sides of the outside of the sidewall of the cover. The guide plates each have a track (1310) which guides the guide elements (1304, 1306) mounted on the cover such that the cover is constrained in its motion when opening or closing in order to avoid damaging the connectors to the VED. The cover further comprises a breach lock mechanism for seating the VED into the VED enclosure by rotation of a sleeve (714). The cover (1002, 1302) defines first (1004) and second (1006) chambers separated by a panel 1010. The top of the VED protrudes into the first chamber through an adapter plate 802 having hole 804 for passage of the VED there through.