bayouboy Posted January 21, 2016 Share Posted January 21, 2016 Not sure if this is the right place to post this but here we go. I recently installed a cobra 29lx and have really high SWR readings. My set up is cobra 29lx with 18' coax going to a 3' adjustable tip firestik. I have tried grounding the mount to the cab and frame no change. I bought a no ground plane set up and still no change. I am using an astatic SWR meter and I can't get them below 3.5. Oh and the truck is a '97 ch613 daycab. Any help would be appreciated. Quote Link to comment https://www.bigmacktrucks.com/topic/43637-high-swr-on-my-cb/ Share on other sites More sharing options...
tjc transport Posted January 21, 2016 Share Posted January 21, 2016 with ohm meter, check both the senter conductor, and the ground on the coax.if either one is not 0 or less than 1 ohm, your SWRs will be way off. Quote when you are up to your armpits in alligators, it is hard to remember you only came in to drain the swamp.. Link to comment https://www.bigmacktrucks.com/topic/43637-high-swr-on-my-cb/#findComment-320986 Share on other sites More sharing options...
bayouboy Posted January 22, 2016 Author Share Posted January 22, 2016 Not sure how to do that. I'll google it and try it. Thanks Quote Link to comment https://www.bigmacktrucks.com/topic/43637-high-swr-on-my-cb/#findComment-320987 Share on other sites More sharing options...
b61mack Posted January 22, 2016 Share Posted January 22, 2016 Have you tried a shorter coax, on my B model with 18' coax the swr was too high then I tried a 12' and it was fine. I heard that the coax had to be 3' increments don't know for sure but it worked. Quote Link to comment https://www.bigmacktrucks.com/topic/43637-high-swr-on-my-cb/#findComment-320993 Share on other sites More sharing options...
MHfred Posted January 22, 2016 Share Posted January 22, 2016 Go to the Firestik website and read what they say about antenna installations. This site would not allow me to copy their address. I think that no ground plane antennas should NOT be grounded. 2 Quote Link to comment https://www.bigmacktrucks.com/topic/43637-high-swr-on-my-cb/#findComment-321004 Share on other sites More sharing options...
bayouboy Posted January 22, 2016 Author Share Posted January 22, 2016 The non ground plan antenna is not grounded. I had a regular antenna on that I grounded. I will try a shorter coax and see if it helps Quote Link to comment https://www.bigmacktrucks.com/topic/43637-high-swr-on-my-cb/#findComment-321077 Share on other sites More sharing options...
Green Dash Posted January 23, 2016 Share Posted January 23, 2016 Where did you attach the antenna mount? i couldn't get a good SWR reading when mounting on the grab handle over the rear window, despite the fact that my company owns several hundred Pinnacles identical to mine where this setup worked fine. I was able to get a good ground by bolting a piece of galvanized "L" angle where the handle attaches to the cab. Quote Jim Link to comment https://www.bigmacktrucks.com/topic/43637-high-swr-on-my-cb/#findComment-321101 Share on other sites More sharing options...
bayouboy Posted January 23, 2016 Author Share Posted January 23, 2016 I used the factory antenna holes on the mirror mounts. I do have a clamp on mount that I may try if some of the other things I'm going to try doesn't help. Quote Link to comment https://www.bigmacktrucks.com/topic/43637-high-swr-on-my-cb/#findComment-321110 Share on other sites More sharing options...
Green Dash Posted January 23, 2016 Share Posted January 23, 2016 The factory antenna system was not working when my truck was delivered new but I had only planned using it until I had a chance to mount my own bracket anyway. I would try your clamp mount on the center of the handle above the rear window and your own coax. Unless clearance is an issue where you travel, I would also go with a minimum 4' antenna. Quote Jim Link to comment https://www.bigmacktrucks.com/topic/43637-high-swr-on-my-cb/#findComment-321128 Share on other sites More sharing options...
mrgumby Posted January 23, 2016 Share Posted January 23, 2016 did you remember to put the nylon insulator in 1 Quote Link to comment https://www.bigmacktrucks.com/topic/43637-high-swr-on-my-cb/#findComment-321138 Share on other sites More sharing options...
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