hi pourang.core wire resistance R=1.7 ohm wire diameter 0.35 c=100 nf calculated indutance must be then 40mh the wire lenght 1.80m ferecunce 10-12khz. the best ferequnce 10.5 khz deep serch 8 meter.goooooood luke.pourang.prodact whites tm600 tm800 tm808 it,s very good whites tm 800 for serch gold nd silver NO found the trash.it is a good metal detector tm800