Review on 📡 Enhanced Tram Browning Black 1246-B NMO Trunk Antenna Mount with PL-259 Connector and 17Ft RG-58 Coax Cable by Cliff Gibs

I installed this on the trunk of a 1999 Toyota Avalon. The bracket fits snugly on the lip of the trunk and I was careful to expose bare metal where the two Allen screws made contact with the lip. I planned to use it with a low frequency whip (Browning BR-140-B) for 10m. After installation, I tried to tune the antenna using the RigExpert AA-55 antenna analyzer. That's when the problems started. When delivered, the antenna should be resonant at around 26.5 MHz. In fact, the lowest SWR, around 2:1, was achieved at around 30MHz. Of even more concern is that the SWR changed erratically when the coax was moved while I was in the car. This usually means the shield is radiant. It should not be. Tests with an ohmmeter with the antenna unscrewed from the NMO mount showed that the threads on the NMO mount where the load coil attaches had continuity between the coax shield and the threads, but no connection between the edge mount and any other part consisted of the actual NMO mount. The lip mount must be connected to the shield of the coax cable so that the shield is electrically connected to the stem when the two hex head screws are tightened. For the sake of a smile I took a copper braid and connected it between one of the allen screws and then screwed a load coil onto the other end of the braid to make sure the connection was correct. After that everything worked as advertised. So if you are having trouble with this mount or are unable to tune the antenna, remove the antenna and check for a short between the NMO threads and the Allen screws. If not, then there is a problem.