MikeOK

I took off my firestik 4' and replaced it with a 3' so I can get in my garage. I had good readings witk the 4' but with the 3' my readings are all over the place. I've tried adjUsting it with the top screw and it's erratic on all channels. I ohmed my cable and it is good, I know I have a good ground. What else can I try?

ShawnInPaso

How long is the coax? Sometimes a longer piece of coax will help.

MikeOK

My cable is 18', just long enough to reach the remote box. My remote box is mounted on a rail behind the glove compartment.

ShawnInPaso

Remote box? Do you mean your radio?

jchappies

redo all your grounds and be sure the antenna base is properly grounded. Be sure the plastic isolator is in the correct location on the antenna base.

Canvas

Try adjusting the SWR at the antenna instead of the radio?

Also check to make sure your coax end is not damaged.

Check for corrosion around the base of the antenna.

R/
Will

MikeOK

The Cobra 75 has all the controls in the handset and the rest is done in a remote box that you can hide anywhere. All that you can see is the handset. I have mine mounted on a rail behind the glove box.

ShawnInPaso

Ah, gotcha.

Well as others have said, it would be good to check and inspect the existing connections (coax and grounds). It's easy to have a coax connector come a bit loose which could alter the SWR.

Then, if you still have that 4' antenna, re-install it and see if you still get good SWR (or not).

If you get good SWR with the old 4' antenna, I'd find or borrow a short length of coax (e.g. 3' ) and a barrel adapter to connect the existing coax with the extra short piece. Then re-measure the SWR to see if the extra length makes any difference or not. If the SWR improves, replace the coax with a single 20 or 25' length. If it doesn't improve (and it were me) I'd return the antenna as "bad" and get a refund.

Edit to add: If your meter has a fwd vs. reflected power setting it would be good to know the values. Often this info is more informative than the SWR.

MikeOK

This is my first cb install so I'm learning. On my swr meter in the forward mode I key the mic and use the adjusting knob to "test" on the meter. Then I turn the switch to "forward" and the reading I get is power out I think. I was able to tinker with it and finally got 1.3 on ch 1, 1.8 on ch 19, and 1.5 on ch 40. I can live with that, it's just a little worse than with the 4'.

I may have just said it backwards but I watched a YouTube video that was using the same meter that I have and I tested it with those directions.

ShawnInPaso

Looks as though you're good to go.