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I am still need to metal detecting and learning an original tdi.  So lately I have been experimenting with the different controls and how they affect the machine. 

 

I read some instructions that mentioned running the gain at the point that the threshold remained steady and did not waiver. This typically leaves me with a gain of 3 or 4.  Does this sound right or am I missing something?

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There is no numeric answer,  we set the gain to match the ground conditions, the hotter the ground the less gain.. In hot ground a gain of 3 or 4 is decent for the first Tdi machines and the Tdi Pro.  Don't fall into the trap of thinking you need to have maximum gain to get results. A smooth and stable machine is usually the best bet, even if it comes at the expense of having to search at a lower gain. When ground balancing do it with a lower gain at first and then experiment with the gain to see how high you can go without making the machine unstable. Every time you adjust the gain, repeat the ground balance.

Every time I go to a new location I experiment with the machine to see which combination of threshold, ground balancing and gain works best. Always carry a test nugget, I use a 1 grain gold ingot..  Give yourself a bit of time to experiment and play at the start of your hunt, to see what settings work best for that location. The type of gold found in the area, the amount of iron trash etc determine Hi Low or ALL conductivity and coil selection.

Again with the original Tdi,  in hot ground a threshold of 3 or 4 sounds alright and I don't think you are missing anything.

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Thank you for the help!  The ground I was on this week was indeed somewhat hot and quite varied in it's mineralization. 

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