I came across this on the interwebz and found it to be quite helpful. Maybe it'll help you out if you're as CB-dumb as I am.

Install an S.W.R. meter between radio & antenna using 3’ coax cable

1. If the S.W.R. is high on CH.1 the antenna is short and must be lengthen

2. If the S.W.R. is low on CH.40 the antenna is to long and must be shortened
{Take your time 1.5:1 is acceptable but try for perfect}

3. If S.W.R. below 2:1 is not obtainable the impedance could be other than 50 ohms {It may be possible to ground the antenna to lower resonant frequency & start over}

4. Best operation in mobile is located on roof and in center of vehicle

5. 2nd best operation is at least 2/3rds of antenna above highest part of vehicle

6. Excess coax should not be coiled { this creates a “ choke” within the cable }
Random stuffing in of cable is preferred

7. If you see 3.0:1 S.W.R across the entire band check for proper ground connection

8. If your install is mobile 18’ is recommend length or coax

9. If your antenna has a rubber cover over be sure to replace it to check S.W.R.

10. If your antenna is mobile make sure all doors are closed and vehicle is away from trees , buildings , power lines or other metallic objects { i.e. signs , cars, trucks, trailers }

11. For fiberglass mounts use a metallic plate on bottom of antenna mount and run an artificial ground to chassis {this should afford the antenna to perform properly }

12. Some mouting materials have a clear coat that may seem to but does not provide a sufficient ground for antenna operation { you may have to run a artificial ground to the body or chassis do not ground to door as it will not provide a sufficient ground }

13. Do not attempt to tune your antenna in the rain or when its wet { as it will give false readings }

14. Use a conductive grease on all connections sparingly { silicone or petroleum jelly will work if no conductive grease is avail }

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Former CRD owner... now I just sit around and stare at the wall.