[Esteban]

Originally Posted by J_Player

Nobody has ever given information about absorption with a stimulator transmitter. For long range metal detecting, the term absorption is meaningless outside the context of light, in which light frequencies can be absorbed by various materials. Another possibility is in reference to RF which can be absorbed by materials depending on the frequency of the RF and the composition of the materials that are absorbing the RF.

According to Esteban, there are emissions from the ground of long time buried metals which he depicted as a sine wave in his diagram above titled "phenomenon from gold signal".
Does this mean that long time buried metals emit a sine wave?

I don't think so.
What does it mean?

-- Nothing that can be measured or demonstrated with any standard instruments. The only instrument that is claimed to absorb these alledged emissions from buried metals is an LRL.
The design and construction details are shown in Esteban's post above so you can build an emission sensor to detect the "phenomenon from gold signal" for yourself and decide if there are any emissions from long time buried metals.

However, the diagrams from Esteban do not show how to build an absorption with stimulator transmitter. It is simply a passive receiver. The basic design of the passive receiver is the same as a simple radio receiver with an amplifier. The important details are in the construction, which apparently is designed to optimize the signal received to select a very specific artifact from the noise being tuned.

If you wanted to build a version that has a stimulator transmitter, then you may need to use a different design than the one shown. Vernell Electronics sells the kind you are asking about which consist of a 555 signal generator to send a signal into a field, while holding a small hand-held coil receiver that tunes RF as you walk through the field. Theoretically, you should find a signal line running from the target metal to the transmitter where you will find altered reception of the TX signal from your coil.

The 555 signal generator has a selector switch that will chose various frequencies used to find different metals. It the early models such as the VR-800, the 555 circuit has no power amp, and simply sends the 555 output to be broadcast.

Here is a photo of another similar kind of LRL that uses a stimulator transmitter and coil receiver:

You're right. The sine wave is only indicative.

Esteban