Review on DHT Electronics 2pcs RF Coaxial Coax Adapter: SMA Male to BNC Male Connector - Improved Signal Quality and Versatile Compatibility by Terrance Singletary

They fit very loosely on the BNC side. They just hang out on the Alinco DJ-580. Twist lock is very weak. Although the radio's locking pins may be worn, any of the standard Alinco and Diamond BNC antennas still snap securely into the radio. However, using any length SMA antenna with these adapters will result in a very loose fit with little locking. I could probably shake the radio so hard that the adapter would just fall off. I don't have much money for it, but it's a pity that good/great adapters are hard to come by. I would pay more for better quality if I could find it.