Hello, Flim:
It would help us a lot if you would post your tvfool report so that we can see what the signals look like at your location.
As was stated above, a DC resistance measurement might be misleading. Just think of a full wave circumference UHF loop that is used in many indoor antennas. It would measure as a short, but it makes a good antenna for strong signals.
Likewise, in a yagi antenna, the center of a halfwave element can be connected directly to the metal boom because that point on the element is at an RF voltage minimum.
Please take a look at this Winegard video:
How To Troubleshoot a Winegard Antenna Cartridge Housing
http://www.youtube.com/watch?v=TlQke5QYbng
If you make the tests in the video and they are not conclusive, I suggest you try another antenna for comparison. That will tell you if the problem is the antenna or the signals.
Please let us know how it works out.