Mine works. Built one 4-5 years ago. About 2-3 db added to the signals on most of my radios, even the Superadios (going by ear, of course).
110 turns of wife around the frame, 365 pf tuner, set next to the radio, and DX away.
Even with Walkmen and similar radios. I DXed the 2013-2014 season with the crate loop and a Sony Walkman and got a lot of new stations that way.