My recent build of a wideband receiving loop using parts from the local home center. Each of the loops are 0.7 meter in diameter and of #12 stranded THHN wire. The wires are fully enclosed in 1/2″ PEX tubing with plastic adapter fittings to the weatherproof junction boxes, one of which holds the amplifier. Currently, the amplifier is the one from LZ1AQ (see http://active-antenna.eu/) but I plan to experiment some more. I don’t have a good reference point with which to compare it (no long wires up yet), but I’ve been very pleased so far with the performance. I’ve since learned that PEX is not very good on UV resistance, so I will probably paint it. But the PEX is just great for holding the shape and it looks cool 
BTW – Lowe’s seemed to have a better selection of what I needed for this project than Home Depot. Everything is plastic. Oh…The gray cylinder at the top is the RA0SMS mini-whip from eBay. Mounted, but not hooked up at the moment. I want to give it another try with a little more elevation and a better ground.
Additional comments:
If you look at the LZ1AQ website and documents, he outlines several different configurations for the loops, but recommends this one as the best starting point. If you mount the second pair of loops orthogonally (rotated 90 degrees as viewed from above), the antenna can be made electrically “rotatable”, but the configuration here gives more gain. I can easily rotate this one by hand in it’s present location. It was also a bit simpler to construct. Later, I’m going to move this up to that shed in the background (i.e. further away from the house noise sources). At that time, I will likely try out an orthogonal config.