VLF stands for Pretty Minimal Frequency and is the same engineering used in detectors developed for coins, jewellery, and relics. VLF detectors broadcast at frequencies measured in kilohertz starting from 3 kHz to 70 kHz. Listed here are five explanation why you may decide on a VLF in excess of http://opensource.platon.org/forum/projects/viewtopic.php?p=12846136#12846136