The text below is from the above referenced PDFs, I've included images of them (ebay doesn't let me post PDFs) in the photos section
A precision flexible-cable connector, the GR TYPE 900-C9, is the latest addition to the GR900 line. Why is such a connector needed ? Connector man ufacturers argue that there is a limit to how good a able connector need be because cables are generally poorer (some cable manu facturers indicate that cable vswR of l .20 i considered good). Some cable manufacturers hold that the cables are good and the connectors have been generally poor ( recent MIL connector vswR specifications are 1 .200- 1 .30) . Actually, both views are valid . ::viost flexible cables have random character istic-impedance variations that p rod uce significant reflection at microwaves ; but nevertheless, very good pieces of cable can be selected . The connector reflection in this case may limit the performance. Hence the need for a good flexible-cable connector. The TYPE 900-C9 Precision Cable Connector meets this need .