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I am planning to mount an antenna similar in design to the Copper Cactus J-Pole on my roof and am looking for good suggestions on how to properly ground it. I am going to mount it on an extra satellite dish (think dish tv without the dish) bracket on the roof. Someone suggested running a wire from the mounting bracket to the pole that feeds my electical supply. This seems a little odd to me. Is the ground supplied via the coax feed-line sufficient or should I do something else? |
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A J-pole antenna does not need a ground to operate. So the only reason to ground it more than just with the coax is for lightning safety. Even lightning safety might be well served with the coax shield if the other end of the coax has a good ground connection to it. If it were me I wouldn't do anything, knowing that I'm in trouble if lightning hits it, but I'd take my chances. But if you want to do everything right, you could run a ground wire from the mounting bracket of the antenna directly to ground in the most direct path with the least bends, and tie it to a ground rod pounded into the ground. I think most hams don't bother to do this. Other than that, read the other two discussions on grounding here and do what makes sense from those discussions. You gotta quit worrying about the details and just get on the air and have fun. Talk to somebody on this antenna first, then worry about grounding it. BTW, the J-pole is one of those antennas where you can really do a good job of grounding the thing for lightning, as it is all one piece of copper that can be connected to ground without affecting performance. If it were mounted on a metal tower, you'd be all set for lightning without doing anything. This is not true with a quarter wave vertical, as the lightning rod part of it is not groundable. In that case you need a "lightning arrestor" which is really just a 50 ohm spark gap to let the lightning energy jump the gap and go straight to ground, only putting about 5000 volts on your coax center lead (which will probably blow up your radio anyway - really hard to protect anything from a direct lightning hit). -Dan, KW2T |
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to be on the safe side just unhook everyyhing you can. ihave had issues with lighting and if your around its the best thing to do....... N4TZB. |
