JK505

Can anyone explain what's happening when I'm trying to get an swr reading?
I have a cobra 29, firestik II, 18' coax.

When trying to get an SWR reading the built in SWR meter goes to about 2.0 for a split second then drops all the way back down. Sometimes it goes all the way to the right into the "cal" section of the meter and then drops back down. This happens while I'm holding PTT.

I thought I had a good ground, sanded the antenna mount down and such. Have read a ground wire helps. If this is the issue can someone explain where to connect the ground wire at? I don't need an SWR of 1 or extremely long distance communication, just enough for the trails.

trouty33

Where is your antenna mounted? My antenna is mounted on the third break light so I have my ground ran to the frame and attached to the break line mount. Not sure why your reading goes up then drops down? Make sure all your connections are tight, and there is no coil in your coax also.

JK505

It's mounted to my third brake light as well. No loose connections. I had the plastic insulator washer on the wrong side at first and it seemed to work fine. Then I noticed I did it wrong and flipped it and now it doesn't work... Wait, I think I just realized how dumb I am. I think I had it right the first time. And the coax only has 3" of slack so it isn't coiled. I'll reverse what I did and try it when I wake up. Thanks! Hopefully you helped me realize I just did something stupid haha

JK505

So my initial set up was this. I get my SWR at 2 having the plastic washer underneath. Which I read was wrong I think. I also cannot get the CAL to fill like the instructions said with the knob. It only fills up to 3.5ish but the SWR meter works this way

JK505

Then I moved the plastic washer (insulator) between the sanded surface here and the metal washer that you see in this picture and that's when the SWR was acting funny. But with the plastic washer on top I can get the CAL full but the SWR acts funny. So which way is correct, insulating washer on top or on bottom?

Coming from an electrical background, it would seem with the insulator on top, the antenna would not my grounded at all. The coax cable wouldn't be grounded either because of the insulation in the cable. With the insulator on bottom, the antenna has metal to metal contact for a ground, through the mount and the tail gate. Right?

SteelBlue Wrangler

The plastic washer goes on the top, dont trust the meter in the radio, find someone that has an external meter you can use to get the correct reading, make sure that you are not parked under any trees or power lines when you take the reading and also have all doors closed on the jeep. Then go from there. I cant see exactly how the washer is placed in the second picture, but it does go on top, and the plastic washer should have an indentation that sits down into the mount.

JK505

Okay thank you! I have like that now. I'll have to find an external SWR meter. I was about 30m away from any tree, power line or building when I checked my SWR. It just seems strange that it jumps to full, then 2, then >1. Do you think it will work this way for the trails?

TURTLECON

Don't trust the CBs internal SWR readings. Use an external SWR meter.

The second pic with the plastic washer on top looks correct. There shouldn't be any metal contact with the antenna post and the mount.

JK505

So I had it wrong the first time, would I have messed anything up or broken something by doing this?

I ran the built in tests when I had it the wrong way, and it said everything was good but the antenna flashed "fail" then "pass" and then held a pass reading. Now it reads everything is a "pass" with the right way

JK505

Daily bump. Gotta go wheeling on Saturday and would like a working CB. Thanks guys