ground noise on base radio ugh!!!!!

[Alabama Buckeye]

LFA acronym or foreign to me. I'm more familiar with PVA, NVA, or LSMFT. Am wanting toroid balun for 25-30MHz.
https://www.kf7p.com/KF7P/RF_chokes.html speak of such over a very wide HF spectrum. Would rather narrow it down. Their example using RG-400 (0.195"D) only slightly less loss than RG-58, has 13 turns on a 240-?? toroid.

Im more inclined to use 12 or 14 AWG stranded copper in lieu of coax. Recommendations would be helpful?