VLF means Really Minimal Frequency and is the same technological know-how Employed in detectors created for coins, jewelry, and relics. VLF detectors broadcast at frequencies calculated in kilohertz starting from 3 kHz to 70 kHz. Here's 5 explanations why you could possibly opt for a VLF over a PI The https://www.authoraevia.com/forum/topic/how-to-detect-coins-relics-and-jewelry/#postid-2469174