Amphenol does make some high-grade 75-ohm BNC bulkhead connectors and such, maybe an RCA adaptor of this series as well. They're the standard silver-plated RG-military-spec type.
But why don't you have the cable re-terminated with a BNC on one end? This would avoid modification to your equipment, and eliminate the added leverage of an adapter to stress the connections.
But why don't you have the cable re-terminated with a BNC on one end? This would avoid modification to your equipment, and eliminate the added leverage of an adapter to stress the connections.