75 Ohm Dual BNC Bulkhead Jack — Right-Angle PCB Tail
The 031-70508: That 75 Ohm impedance is the key spec — it tells you this is a video/CCTV/surveillance connector, not the standard 50 Ohm BNC used in RF/data. It's rated to 1 GHz with 0.2 dB insertion loss, which covers composite video, HD-SDI, and baseband surveillance signals cleanly. The mounting is a hybrid: panel mount via a bulkhead front-side nut, plus right-angle through-hole solder tails that drop into the PCB. That means the jack bolts to the panel first — the nut clamps it against the bulkhead — then the right-angle pins solder into the board. Common layout for a video distribution panel where the BNC jacks sit on the rear panel and route to a PCB inside. Two ports on one body — each is an independent 75 Ohm signal path in a single panel cutout. Saves panel space compared to two separate jacks.
What the 75 Ohm Rating Means for Your Signal Path
75 Ohm is the standard impedance for video and CCTV — not 50 Ohm. If you drop this into a 50 Ohm system, you get a 1.5:1 VSWR mismatch that reflects signal at the transition. The 1 GHz bandwidth and 0.2 dB insertion loss cover SDI, HD-SDI, and analog composite video without rolling off the high-frequency detail. The gold-plated phosphor bronze center contact keeps the contact resistance stable across those 500 mating cycles. The zinc die-cast body with nickel finish provides the RF shielding the 1 GHz signal path needs. Nickel resists corrosion on a panel that may see humidity or cleaning fluids. The polypropylene dielectric holds the 75 Ohm impedance consistently through the bulkhead transition.
Board Lock and Installation
On a right-angle part like this, the board lock takes the shear force from cable strain off the signal pins. Without it, repeated cable movement can crack the solder joints at the right-angle tails. The silver housing color is standard for nickel-plated zinc — no special paint or marking.
How the 2-Port Compares to Single-Port BNC Jacks
The 031-70508 carries two ports on one body; the single-port peer 031-5538-10RFX carries one port in a bulk package. Both are 75 Ohm, both rated 500 V, both use the same zinc/nickel body and polypropylene dielectric. The 2-port saves one panel cutout and one nut per two signal paths — useful when you're populating a 16-channel video distribution panel and every millimeter of panel space counts.