Emi And U & I

[HardPack]

Several of you commented on the SMF vs EMI post, thanks for the input. Here is the back story of the detecting site impacted by all that EMI.

During the 1850’s approximately 15,000 people occupied a relatively short drainage system flowing into a main river. Once the trails and supply lines were established and due to the low elevation placer mining could be conducted year round. Upstream are quartz outcroppings of the mother lode. However, along this lower drainage a major source of gold came from a basin higher upstream beyond the main lode deposits. The story goes that an old river flowing off a Nevada Plateau made large deposits into this upper river basin. Over the proceeding 55 million years younger streams came and went carving down through the upper basin carrying off some of these older deposits. In the early 1850’s prospectors located gold placers in bench gravels along the lower reaches. Soon thousands of miners were diverting water by means of numerous ditches and elevated wooden flumes to cascade water over these gold bearing terraces of concreted bench gravels.  A trading post was established early on and the profits soared. Today located dead center of all this history is a hydro-electric power plant equipped with a switch yard and high voltage towers carrying away more mountain wealth to the coastal rich. The EMI of today is having a major impact on the leavings of yesterday, not to mention my attitude.

Only the litter of rusted can goods commemorate the pack trains, trade goods and tent platforms of the golden past. The old bench placers are buried in vegetation, reptiles, felines and a washed in EMI. All this inhospitable has resulted in very little modern trash other than the remains of shooting into the darkest. 

Here’s my point regarding the impact of Electro Magnetic Interference (EMI) on Simultaneous Multi Frequencies (SMF) detectors. Site conditions have to be addressed in order to successfully detect targets whether it be ground mineralization, trash loads, UFO’s, etc. At this location EMI is only one of many site conditions. So my choices are to either to detect on another site or stay put and adjust settings. I can attempt to mitigate the site conditions with the detector in hand or switch detectors. I can change coil size, switching from a DD to a Concentric coil (might be a good option if only ability of a SMF VLF detector), adjusting the Sensitivity down, Recovery Speed up, repetitive Noise Cancelling, reduce target detection depth on deep targets and finally switch the SMF detector to a single frequency. All this effort spent on only one of the many site conditions, days are short and it is growing dark. Once the SMF setting is switched to a single frequency (SF) to address the site specific EMI erupting audibles the door swings completely open. And what do I see… Nexus, Deeptech, and a trusted White TDI SL with its “high tone/low tone switch knob” and folded mono coil.

I am feeling better already. I think I’ll take this SMF detector for a day on the beach. Perhaps we’ll establish a better understanding along the reaches of the sunny beaches shaded only by the cooling towers of the Moss Landing Power Plant.