SMA Jack for RG-405 Semi-Rigid — 12.4 GHz, 1000-Cycle Duty
The Hirose HRM-100-3S(09) is a 50 Ohm SMA jack, female socket, designed for panel-mount applications using RG-405 (.085" semi-rigid) cable. It is the flange-mount member of the HRM series, with a threaded fastening interface and a single port. The connector is rated from DC to 12.4 GHz with an insertion loss of 0.1 dB, and is specified for 1000 mating cycles — well above the 500-cycle baseline typical of economy SMA parts, indicating gold-over-beryllium copper contacts that hold up in test-equipment or field-service environments where the connector is mated and unmated regularly. The silver housing colour is the natural stainless finish — no plating to flake or wear in harsh environments.
The 12.4 GHz maximum frequency covers the entire X-band (8–12 GHz) and most Ku-band satellite downlinks, with headroom to 12.4 GHz. The 0.1 dB insertion loss at the connector interface is low enough that a single mated pair adds negligible attenuation in a short cable assembly — the loss budget is dominated by the RG-405 cable itself, not the connector. For comparison, a standard SMA jack with a brass body and tin plating might spec 0.3 dB at 12 GHz and 500 cycles; the Hirose HRM holds 0.1 dB and 1000 cycles through the gold-plated beryllium copper contact and stainless body.
Termination and Cable Preparation — Solder Shield, Solder Contact
Both the shield and center contact are solder-terminated. The shield termination uses a solder cup or ferrule that accepts the RG-405 braid; the center contact is a solder-post design. For a harness builder, this means the cable end must be stripped to expose the center conductor and dielectric to the correct length — typically 0.125" for the center pin and 0.200" for the shield — and soldered with a controlled-temperature iron to avoid melting the PTFE dielectric. The flange mount uses two through-holes for #4 or M2.5 screws; the panel cutout is a standard SMA D-hole per MIL-STD-348.