in my 139 x i have the mod 500 model antenna. the antenna does not rotate at all so as to pick up or tune in stations. i called the vendor and they could not tell me why its not rotating. i pulled down the plastic handle but it feels like its frozen, won't budge to the left or right. there is a round hex nut on the upper unit (up on the roof), is that able to turn using a wrench to help rotate the antenna?. don't want to do something to start a water leak. ugh.