As long as your radio has an internal ferrite antenna then you already have a magnetic coupler! Just bring the two close together and experiment a bit with the the position of the radio against the loop for the best signal. Another approach is to buy a piece of ferrite rod or salvage one from somewhere - if you salvage one from a busted radio with coils on it, even better. Wind a few turns of insulated wire around the rod and connect the two ends of the wire to the output socket on the amplifier. Again experiment with the placement of the rods and the radio for best signal transfer.
Yeah, that would work, but honestly I was preferring something with a 'clean appearance' and little less of a time investment. While I know and understand the principles behind it and could probably buy the parts to make one off of Ebay, it may not be as efficient and for sure not a pretty or sturdy. In the end, I may be forced to go down that path, but my den is enough of a mess right now, I just don't have the heart to mess it up even more.
From what I've been able to determine, interest in radio has tanked since I left the hobby about 20 years ago. I'm glad you guys are here, because otherwise it would seem like a giant wasteland.