Topband: Magnetic Loop Height Question

[W7TMT - Patrick]

I'm looking to improve my receive situation on 160. Given the numerous limitations to my location it appears my best chance of seeing any improvement might be a small loop. All of the designs specify a minimum height of above ground. The DXE version suggests 5 foot as a minimum and other designs are similar. Any thoughts on what that number would be if we are talking about super conductive ground below it, in this case saltwater? Any other considerations with a loop over seawater?

Thanks for your time.

73, Patrick, W7TMT