27MHZ CB SWR

G'day Leg, acceptable SWR is 1.5:1 or less on Ch 20. With your mounting, check the Z bracket is earthing properly to the vehicle body and the coax is earthing to the bracket. The best way is to get a multimeter and see if there is continuity from the coax plug to a metal part of the body. While your at it check there isn't a short between the coax outer braid and the centre conductor and that the centre conductor is making contact both at the plug and the antenna base. If all these are ok check SWR on Ch 1 and then on Ch 40. If the SWR is lower on Ch 1 than Ch 40 then the antenna is to long and has to be trimmed shorter. If it is lower on Ch 40 than Ch 1 it's too short and you could need another antenna. What sort of antenna is it? If it is a fiberglass whip and it is too long you can carefully cut it back with good side cutters cutting about 3mm/1/8" at a time checking the SWR as you go. Do this on Ch 20 until it comes below 1.5:1 or lower and you should be right for all 40. Any questions ask away.
Regd's Darryn

2.4:1 isn't good at all don't know how any instructions could say it was acceptable.
Darryn is on the ball and make sure you are checking in an open area with no nearby large objects....ie in the driveway up against the house.

Got my SWR checked by a pro years ago and have not changed the installation since - not sure of the values - the PC122 XL is a solid unit - pity nobody listens to 27 much anymore - I've been out 2500km in the middle of the day, while mobile on mine. Not being worth a lot, but as new, and installed in the dash, mine is staying put - a back up to the long distance HF.