On our '13 Columbus, our external antenna on the roof snapped during our first winter. It WAS one of those short, plastic/rubber-like antennas....now that it's gone, our reception is, predictably, poor. So...if you DO have an antenna mounted on your roof, you may want to see if it's even cracked or, if it's completely missing...?! I would think that you at least have a screw-on port somewhere on your roof for a radio antenna!? It's also possible that the factory never did plug in the antenna on the back of your Jensen unit when it was installed. I would check that after checking out your roof situation! Best wishes and happy camping!