Common characteristics in the phenomenon
 

hi
I study the time I was researching on different circuits lrls.Almost all of them had one thing in common .If the source a frequency placed in the range of phenomenon Change Amplitude - frequency - phase.I think with study on one of these three characteristics can reveal buried metals.I think it is very effective as the antennas use ferrite Because of the high permeability
What do you think about this design?

hi
Today I made an oscillator with a LC circuit.With the touch of a telescopic antenna frequency increases.I do not know whether is the effective to detect the phenomenon?Please comment

Dual In-Line Package, 14 Pins
:???: 4001

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Antennas in the direction of propagation of the waves
But there lay the path is mostly ferrite

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The new machines were built after 2010, mostly with ferrite cores are digital
;)

:) I belive it should look good acording to your explaination