Prospecting for placer gold

[jeep6789]

Among the numerous forums, I have no idea which circuit is suitable for detecting gold in the river. I need to make a mini machine to detect in the river. Could anyone tell me?

[Carl-NC]

Rivers are difficult for metal detectors. The gold is usually under a lot of overburden and must be dug out. It also tends to be very small and difficult to detect even if it is shallow. And rivers are full of hot rocks that have been carried down from different places so that there are a lot of different loss angles to deal with all at the same time. River prospectors tend to use a dredge, sluice, highbanker, or pan over a metal detector. But it all depends on the particular river. If the river has exposed bedrock then a metal detector might be suitable for detecting cracks and crevices.

The typical tiny size of river placer suggests a high frequency VLF will work best. But if the river has a lot of hot rocks, it will drive a VLF crazy and you will need a true ground-balancing PI.

[kt315]

i almost forgot this type of detector... so much discussion was in later... so much activity of the geotechers... look FALCON MD20.
sometimes the activity gives birth to nothing.

[Qiaozhi]

Here's everything I have on the Falcon MD20.
The TX frequency is 300kHz, and the pinpointer head is a D10mm ferrite rod with 60 turns of 0.2mm wire.

[Carl-NC]

The Falcon is just a simple energy-theft pinpointer, works the same as a Garrett Pro-pointer. The only special thing about it is it runs at 300kHz.

[Mario-j23]

If I had gold in my rivers, I would definitely try this:

https://www.ebay.com/itm/23400593370...;itmmeta=01K9W 968S 4S9JDQW38YXZ116RV&hash=item367bd72e8b%3Ag%3AzX EAAO Swwetkiyl7&itmprp=enc%3AAQAKAAAA8FkggFvd1GGDu0 w3yX Cmi1cv4u%2FdNSpVQT0LdCsQwO9%2Bb1%2Bq74Z%2BjY8kYOjL lvgCbfN719pnH0d0t%2FgRBSHe9WqL6ZyYEneUGMpNfW%2BzQW poDETtK%2B7MVSkdfOc3w23uQV8vTlfHeOpiOxkb3WCl740DFX yWMct5WQLZ4U%2Fwl%2Fflju5CKc3kE0GS2UrM4kkXICXM6lo9 2CmF1bXSehOALH84Shzx2ze2SLVqgoKwYsPSzte3B1YBk4Uj4V xk9ML7gVZVQcPwJeJGZCgUbNPvwoE0ng7nL8g9Hnru6enTCng6 tuoSBr5V6wzhRj2JIUvk2Q%3D%3D|tkp%3ABk9SR-yMmYnPZg&LH_ItemCondition=3000|7000

Sorry for the little joke in this gloomy autumn weather.

[Mario-j23]

Seriously though. I tested my XP Mi-6 pinpointer and it detects a 5x5 mm piece of kitchen foil. It doesn't detect anything smaller.