Hi Nenad,
I am considering buying a large DD coil and running it in RX Mono mode. I have a 4500 detector. Looking at some test results of yours June 21 2019. Target 3, 93 grams lead.
4500 &5000 NF 25 " Mono, Sen Ext 69 cms. I would be interested to know whether the setting of RX Mono, Normal...