Inexpensive covers for large microwave hybrids

A thin, resistance-welded cover provides a cost effective (microwave-box) seal with the following attributes: 1. Covers are lower priced because dimensions are not tightly toleranced. 2. Cover alignment is not critical. 3. Box edges may be irregular or damaged without affecting the seal quality. 4. Rework is fast and simple. S. Seals are hermetic. 6. Internal isolation can be made by welding the cover to baffles. 7. Commercial equipment is available for weld sealing. An electrode change is the only modification required. 8. Operator training is minimal.