75 Ohm F-Type Pass-Through for Bulkhead Installations
The Amphenol RF 531-40120 is a straight F-type jack-to-jack adapter, designed for in-line signal pass-through through a panel bulkhead. This adapter mounts through a panel cutout using the bulkhead feature, secured with a lockwasher and nut (not included). The straight body keeps the cable run coaxial with the panel — no right-angle bend to stress the connector or the cable jacket.
How It Compares to Similar F-Type Adapters
The key difference is frequency range: the 222121 is rated to 2 GHz, while the 531-40120 tops out at 1.2 GHz. For satellite IF work at 950–2150 MHz, the 531-40120 covers the band but leaves no margin above 2.15 GHz; the 222121 gives headroom if the system ever runs DOCSIS 3.1 upstream signals above 1.2 GHz. Both use tin-plated brass bodies and tin centre contacts, so corrosion resistance and mating cycle life are comparable. The 531-40120 uses a PTFE dielectric; the 222121 uses polypropylene — PTFE holds its dielectric constant more tightly over temperature, which matters for phase stability in longer cable runs. Against the right-angle 222F-90, the 531-40120's straight body is the correct choice for a bulkhead pass-through where the cable exits the panel on the same axis. The 222F-90 introduces a 90° bend, useful when the panel depth is tight but adds a stress point on the cable if the run is rigid.
The 531-40120 is listed as Active on the manufacturer's lifecycle record — no last-time-buy or end-of-life notice is in effect.