Hello,
I just installed a Comet CA-2X4SR antenna on my pickup. I installed it using a ball mount by attaching it to the truck bed side of my tool box just behind the driver seat. Since the antenna has a PL-259 connector, I used a stud to SO-239 adapter to mount the antenna to the ball mount. I have also run a 1" ground braid from my trucks frame to the ground plate on the back of the ball mount (inside the tool box). To stiffen the installation I used a 1/8" steel backing plate to sandwich between the ball mount's backing plate and the wall of my aluminum toolbox. When I checked the VSWR I get a 1.8:1 in the 2m band and a whopping 3.2:1 in the 70cm band. Neither is really what I was looking for, but the 70cm VSWR is unusable. BTW, The top of the antenna is about 1 1/2 feet above my trucks cab, but most of the 40 inch antenna is below the cab.
Does anyone have any suggestions for improving the VSWR? I was thinking that raising the antenna a foot or so would help, but I could not find a extension pole that had a PL-259 connector on one end and a SO-239 on the other. I am not sure how I could improve the ground plane without moving the antenna and leaving a big hole in my weather-tech toolbox. According to the manufacturer, the antenna is factory matched to deliver a max 1.1:5 VSWR in both bands and is not adjustable. Also, I was wondering what impedance I should expect to see with the antenna installed on the ball mount and measuring between the center pin of SO-239 inside my toolbox and the backing ground plate. I was thinking that perhaps I have a bad or shorted connection in the ball mount.
Any help would be greatly appreciated.
I just installed a Comet CA-2X4SR antenna on my pickup. I installed it using a ball mount by attaching it to the truck bed side of my tool box just behind the driver seat. Since the antenna has a PL-259 connector, I used a stud to SO-239 adapter to mount the antenna to the ball mount. I have also run a 1" ground braid from my trucks frame to the ground plate on the back of the ball mount (inside the tool box). To stiffen the installation I used a 1/8" steel backing plate to sandwich between the ball mount's backing plate and the wall of my aluminum toolbox. When I checked the VSWR I get a 1.8:1 in the 2m band and a whopping 3.2:1 in the 70cm band. Neither is really what I was looking for, but the 70cm VSWR is unusable. BTW, The top of the antenna is about 1 1/2 feet above my trucks cab, but most of the 40 inch antenna is below the cab.
Does anyone have any suggestions for improving the VSWR? I was thinking that raising the antenna a foot or so would help, but I could not find a extension pole that had a PL-259 connector on one end and a SO-239 on the other. I am not sure how I could improve the ground plane without moving the antenna and leaving a big hole in my weather-tech toolbox. According to the manufacturer, the antenna is factory matched to deliver a max 1.1:5 VSWR in both bands and is not adjustable. Also, I was wondering what impedance I should expect to see with the antenna installed on the ball mount and measuring between the center pin of SO-239 inside my toolbox and the backing ground plate. I was thinking that perhaps I have a bad or shorted connection in the ball mount.
Any help would be greatly appreciated.