I've run into an interesting interference situation when trying to pick up WCWN on channel 43 in Kingston, NY. The signal has been fine except for times when there have been enhanced tropo conditions. Here is the tvfool report for the location:
http://www.tvfool.com/?option=com_wr...3e478328944048
The first antenna tried was a Scala PR-TV
http://www.kathrein-scala.com/catalog/PR-TV.pdf antenna When the problem was noted, the best guess for interference was WFFF on channel 43 on Mt. Mansfield, VT. To solve the problem I used a pair of Antennas Direct C-2 antennas stacked horizontally the optimum distance to null WFFF while aimed at WCWN. The C-2 antenna was chosen because it is less likely to be bothered by ice than a yagi style design.
Thanks to Antennas Direct for helping resolve the problem.