I've been making minor improvements to the antenna recently, such as making the tripod more stable, remounting the variable capacitor, etc. I found a rubber covering from a banana plug to put on the capacitor where a knob goes (I never found a knob that really fit it). So, now that I'm able to tune without causing a short or ground or whatever makes the signal drop out from direct contact, I have discovered that the upper range is much higher than previously thought. I just logged Russian polytone station XPA2, which broadcast at 1500z today (9/16/16) on 16147 USB using the loop. And it came in much better than it did on the 48' wire, which at 14.4m is usually quite reasonable for higher band reception.
Up above I said I don't think this is a true DX antenna, but I'm reconsidering that conclusion.