Greetings all, complete newbie to all things radio, researched for a few weeks and settled on a GMRS system for my vehicle.
I'm installing a Midland MXT400 and paired it with the MXTA10 3db gain antenna. I've got my antenna cable ran to my NMO mount and have confirmed solid ground of the mount, as well as good circuit isolation between the NMO mount center pen and the threaded mount, as well as the vehicle. I've also checked at the radio end, the PL-259 has isolation between positive and ground, and has continuity with the ground and vehicle ground. So it appears that the cable and mount are fine.
So I went to measure SWR with a Kalibur SWR meter designed for a CB system. After adjusting the system to Low power, and adjusting for the needle to hit the Set at the end, I switched it to Ref and hit transmit and it immediately redlined. Now after that happened (and an immediate bad electrical smell from the SWR) I've done more research and I expect to be told that this SWR meter is no good for GMRS or for the wattage of this unit, or both. BUT...
Since it looked like I was getting 100% reflection, I thought I should double check for a short, and lo and behold, the whip on the antenna has continuity with the mount and ground. I re-checked my cable run and mount and it still seemed properly isolated so I tested the center pin on the antenna to its own inner threads, and there is continuity, a complete short. Same from the whip to the inner threads, and when screwed onto the mount, between the whip and vehicle ground. Shouldn't those be fully isolated from each other? It was hard taking the pictures while holding the leads, but I assure you the leads are not touching.
Any help is appreciated. I've unplugged everything in the meantime, as I'm not keen on starting a fire.
I'm installing a Midland MXT400 and paired it with the MXTA10 3db gain antenna. I've got my antenna cable ran to my NMO mount and have confirmed solid ground of the mount, as well as good circuit isolation between the NMO mount center pen and the threaded mount, as well as the vehicle. I've also checked at the radio end, the PL-259 has isolation between positive and ground, and has continuity with the ground and vehicle ground. So it appears that the cable and mount are fine.
So I went to measure SWR with a Kalibur SWR meter designed for a CB system. After adjusting the system to Low power, and adjusting for the needle to hit the Set at the end, I switched it to Ref and hit transmit and it immediately redlined. Now after that happened (and an immediate bad electrical smell from the SWR) I've done more research and I expect to be told that this SWR meter is no good for GMRS or for the wattage of this unit, or both. BUT...
Since it looked like I was getting 100% reflection, I thought I should double check for a short, and lo and behold, the whip on the antenna has continuity with the mount and ground. I re-checked my cable run and mount and it still seemed properly isolated so I tested the center pin on the antenna to its own inner threads, and there is continuity, a complete short. Same from the whip to the inner threads, and when screwed onto the mount, between the whip and vehicle ground. Shouldn't those be fully isolated from each other? It was hard taking the pictures while holding the leads, but I assure you the leads are not touching.
Any help is appreciated. I've unplugged everything in the meantime, as I'm not keen on starting a fire.