Microwave bytes - VNA Tales

The first topic under this heading is the vector network analyzer, or VNA, as it has now become known, to distinguish it from its lowly scalar relation. Not that the VNA in its modern form has fallen by the wayside - far from it. But the history of this subject is of some interest, and it also has a noteworthy skeleton in its closet - the ill-fated six-port reflectometer (6PR).