TV Fool has been a very helpful tool for me to use to determine what antenna and height to try first on customer's sites. I use it and the antenna field maps that used to be available at the REC website. I wish they were still available. My Avatar is the pattern from KVOS-12 (35) Bellingham, WA and I live just south of the red ring. To receive them I built a 15-bar Yagi with coaxial balun and have their signal at a solid 65. By the way, I tried it first with a 'Rat-Shack' balun and the signal was a solid 55, so there is a difference...
Regarding the two local antenna 'farms' to my East-ish, TV FOOL is dreadfully inaccurate here do to my hilly and shadowed location, but it is very accurate on distant stations. As far as range, I can receive 47 (a low-power translator) to the south-ish, 50 to the SE and the analog carrier from 10 to the NW in Canada, and that was on my 35 Yagi. Next summer I'll try for that station with a more appropriate antenna. Attached is my TV FOOL chart.
PS I have no clue why the attachment shrank itself. I sent it as a .png and now it's a .jpg ... hmmm. Here's the direct link to my location.
PPS I checked this morning and the maps are again available at the REC broadcast query website!