There were some RF connectors that looked like the RCA phone connectors, except that the center pins were shorter, used in General Electric mobile radios, up to 460 MHz. I would assume that there were pretty well matched.?
Until the SMA connectors were available, at reasonable prices, there were many small RF connectors in use. Many were quite expensive. At that time there was very little standardization. The precision TNC connectors work well above 10 GHz and are still commonly in use for higher power microwave use.
There are versions of the SMA that are designed to be used to 26 GHz, but generally the less expensive ones are OK only to 18 GHz. The 3.5 mm and 2.92 mm versions are designed to work at even higher frequencies (to 40 GHz).
