50 Ohm AUTOMATE Plug for RF Harness Builds
The Amphenol RF FM4-NDSP-PCB-1 is a miniature coaxial plug from the AUTOMATE series, terminated as a male pin for through-hole solder attachment. It's built for controlled-impedance signal paths at 50 Ohms, with a usable bandwidth to 9 GHz — the limit before the interface's VSWR starts to climb. The Code D keying variant prevents cross-mating with other AUTOMATE codes (A, B, C, E, F, G, H, K, L) in the same harness, so the RF path stays pinned to the right channel. The latch lock fastening gives a positive audible click on mate, and the 25-cycle rating means this is a fit-and-forget connector for production harnesses, not a daily test port.
Code D vs Code C — The Keying Difference
The AUTOMATE series uses colour-coded keying variants to prevent mis-mating in multi-channel RF harnesses. The FM4-NDSP-PCB-1 carries Code D keying (violet and claret housing colours), while Code C uses a different key profile and colour. A Code D plug will not physically mate with a Code C receptacle — the keying pin position is non-negotiable. If your BOM calls for Code D, a Code C part will not insert, so the harness build stops at the connector.