Make that a sample of 3.
With the included loops on my Accurian and my HDT-1, I have no trouble receiving two of my locals (WHAM 1180, about 8 miles away, putting 25-30 mV/m over me, and WHTK 1280, about 2 miles away, with about the same signal level). The loop does not reliably give me a lock on my third AM HD local, WLGZ 990. It's about 17 miles from me, delivering about 3-4 mV/m daytime and a little less at night.
As for my friend w9wi, I believe his "locals" are actually quite a distance away (40-50 miles, if memory serves) over some pretty lousy ground conductivity, which is to say that he has to be a DXer to hear them, period.
More like 20-30 miles but yes. Actually, I probably don't need 260 feet but I don't have anything bigger than the loop & smaller than 260 feet! I'd bet 30-40 feet of wire run under the eaves would do the trick.
My two AM HD locals are at the top of the band, (1430 and 1510) and this *is* Tennessee where, as Scott says, the ground conductivity stinks. Neither station comes in in HD at night. (1430 doesn't come in in analog either, and 1510 is subject to severe interference.)
Actually, let me add a fourth and fifth sample(grin).. Same radio, in Madison, Wis., with the loop receives WHA-970 reliably in HD from about six miles, in a motel room. (normally a pretty noisy location) Didn't have enough daylight to test any other stations, and this was before nighttime IBOC was allowed.
And in Menomonee Falls, with the loop it gets WTMJ-620 and WISN-1130, both about 30 miles away. I think the lower dial positions of both stations help, as well as the much better ground conductivity *and* the fact that both stations are directional, favoring the location where I was staying. (effective radiated power well over 50,000 watts in both cases) I could *not* however lock on WOKY-920, 5,000 watts also aimed in my direction and 5-10 miles *closer* than WTMJ and WISN.