Originally Posted by rbinck
One more thing that jumps out for me is according to the tvfool report for zip 33410: http://www.tvfool.com/?option=com_wr...90383236229ff3
It shows NBC on real channel 12 and CBS on real channel 13. I hope that is just wrong data because with them both from the same location like it shows, there will be a lot of co-channel interference which would explain why you have trouble with those channels. I'm surprised to see that as usually there is more separation than that.
I don't see a co-channel problem; co-channel means same channel. NBC and CBS are adjacent channels, meaning next to each other.
Dave already has enough problems with weak VHF signals, UHF signals in two directions, buildings in the signal path, trees, and his antenna should be grounded.
If the antenna is outside, the coax shield should be grounded with a grounding block that is connected to the house electrical system ground with 10 gauge copper wire for electrical safety and to reject interference. For further compliance with the electrical code (NEC), the mast should also be grounded in a similar manner to drain any buildup of static charge which will tend to discourage a strike, but the system will not survive a direct strike.