Sounds like the loop I have here. Dentron Supertuner with 450 Ohm balanced line. I added about 100 feet of wire to it about a week ago from about 350' feet to about 450'. It works great, and it's fantastic for SWL. Even AM Broadcast Band DX.

Definitely make it shorter than this if you want 40 and up.

With the shorter length version, I played with lowering the west (feed point) side of the loop, as a sloping loop. It helped to kill the QRN a little, and I was louder on the left coast.

Called it the Sloppy Loop.