12-1 OTA weak signal

[QuimaxW]

I live on a hill in Waukesha, all of the other channels come in fine except for channel 12. I get a really low signal, causes pixalation and occasionally a complete loss of signal.

Is 12's signal just weaker than everyone else's or is there something else I have to retune?

[AA9VI]

Low antenna, just like WTMJ.  Not to mention, WTMJ is 1MW ERP, WISN is 863 kW ERP.

I posted the antenna heights here:
http://www.milwaukeehdtv.org/forums/showthread.php?t=8675&page=2