What is the recommended grounding technique for the shield of a coaxial cable at a bulkhead connector?

The recommended grounding technique for the shield of a coaxial cable at a bulkhead connector bonds the cable's outer shield to the enclosure wall with 360-degree circumferential contact, ensuring that EMI currents flowing on the shield's exterior surface are grounded directly to the enclosure panel without creating apertures or slots that would radiate. The key principles: 360-degree bond (the cable shield must contact the bulkhead connector shell around its entire circumference, not at a single point; a single-point pigtail ground (wire from the shield to the panel) creates a slot antenna that radiates at frequencies where the pigtail length approaches lambda/4, completely defeating the shield ground), use a proper bulkhead connector (a threaded or bayonet bulkhead connector provides the 360-degree bond automatically when the cable connector is mated; SMA, N-type, and TNC connectors with bulkhead adapters all provide excellent 360-degree grounding; BNC connectors provide adequate grounding for most applications), keep the connection short (the shield-to-panel connection must be as short as possible; any wire lead, pigtail, or gap between the shield termination and the panel adds inductance, creating a high-impedance path at high frequencies that allows EMI leakage), and ensure clean contact surfaces (the panel surface at the connector mounting location must be bare metal with no paint, anodize, or oxide layer; clean, bare metal provides low contact resistance (less than 1 milliohm) for the shield-to-panel bond). What NOT to do: do NOT use a pigtail wire from the cable shield to the panel (this is the single most common EMI grounding mistake; the wire's inductance creates a high impedance at frequencies above approximately 10 MHz, allowing shield currents to radiate).