All three coils arrived today, but I have only had a few hours to fiddle with them. They all work very well, but I am finding some surprises. For one thing, they appear to pick up signals off the rim instead of broad side, and inductive coupling when tuned with a cap is also best with the windings in the radio ferrite antenna parallel to the diamond weave coil windings. Even good radios which are not helped much by the SAT or TERK can receive a huge boost from the 9.25 inch OD AM BCB 350 uH coil. On some sets like that, there is a huge peak at a certain point along the internal ferrite antenna, and others not so much. I noticed on one modest portable tuned to a fairly weak, but listen able station, when I brought it near the coil tuned with a cap to the same frequency, it completely nulled the signal when broadside to the coil, and had a strong signal when in a parallel position. I am tuning with a vernier cap from Crystal Radio Supply, and there is no sign of a sharp peak which is hard to tune. I haven't tried a cap without a vernier yet.
The RSSI readings with just the MW coil hardwired to the PL-360 are greatly improved over the tiny factory ferrite, and so far seem at least as strong as Gary's 7.5 inch ferrite custom made antenna. They do behave differently as far as noise and nulling, so it is hard to make comparisons.
-FARMERIK