What this connector is — Molex 43860 Series, 6p4c RJ11 jack
The Molex 0438600003 is a 6-position, 4-conductor (6p4c) RJ11/RJ14 jack from the 43860 series. It is a Cat3-rated modular jack — the standard for analog phone lines and low-speed data up to 16 MHz, not Cat5e or higher. The single-row, single-port design is unshielded — no metal shell for EMI containment, so it relies on the system enclosure for radiated emissions compliance.
The Cat3 rating limits the jack to 16 MHz signal bandwidth. This is fine for POTS (plain old telephone service), RS-232 over twisted pair, or 10BASE-T Ethernet at 10 Mbps — but it will not pass Cat5e (100 MHz) or Cat6 (250 MHz) certification.
Pinout and termination
The 6p4c (6-position, 4-conductor) pinout maps to the centre four positions of an RJ11/RJ14 plug — pins 2 through 5 on a standard 6-position modular plug. The two outer positions (1 and 6) are unpopulated. The jack mates with any standard 6-position modular plug (RJ11, RJ12, RJ14) with the same 4-conductor wiring.
Mounting and board layout notes
The right-angle through-hole footprint with board lock requires a PCB cutout or slot for the lock tabs — the datasheet footprint drawing shows the keep-out zone. The tab direction is up, meaning the locking ramp faces away from the PCB. The unshielded body means no ground-plane stitching around the jack; just route the signal traces to the through-hole pads. Tube packaging (not Tape & Reel) indicates hand-placement or low-volume wave-solder assembly.