Bill Rinker, W6OAV, handcrafted this compact magnetic
HF loop from copper and pvc plumbing supplies, a 12 volt motor, and some teflon sheets. He's had great reports with it.
One of the beauties of building the loop inside a box is that Bill can set it out in the yard and neighbors don't know it's an antenna. It almost looks like a fan.
This is the "trombone" assembly which slides up and down as the motor turns.
The trombone is part of the tuning capacitor and
tunes the loop remotely as it moves.
The feed point where the coax attaches.