Quote:
Originally Posted by Dubulumach
Francoitaly keep in mind that appearance of so called "the compass effect" is due to very high dc gain. Lower overal gain and lrl going out from "the compass effect". It is artificial effect made by us not the phenomenon.
Also, you have no proof that the phenomenon amplitude is variable at a given area of prospecting. Maybe phenomenon amplitude is mainly constant, while on some unknown way rise or decay amplitude and phase of oscillator. In my opinion phenomenon noise has unknown bipolar nature, very wide bandwidth and maybe have some unknown 3rd component which change both amplitude and phase of lrl reference signal.
There are only to ways imho to explain such odd manifestation of phenomenon signal at referenced oscillator signal. They are speed up or slow down charge carriers (electrons-holes) migration through the base-emitter juntion of tr2 bc183c transistor. It means increasing or decreasing emitter current of tr2.
We should easy monitoring this variations by simply puting current transformer around emmiter leg withouth affecting amplitude of the current, and amplify that tiny current by 3 lm358 op amps in the differential configuration.
The question is one: Does phenomenon signal or phenomenon noise is current or voltage dependent or both ?
Best regards 
Dubulumach |
The causes of the phenomenon are practically unknown, but I think the compass effect has much in common with the phenomenon. In fact I realized that the phenomenon was real when I realized that my lrl was sensitive to the compass effect. To make a comparison, imagine that lrl is a boat that navigates by following the current of a river (this current could be the solar wind flowing in the north / south direction). If there are no obstructions the boat will proceed regularly (there are no signals revealed by lrl). If there is an obstacle (a big rock) close to that point the current is no longer uniform and the boat is warned of a change (the lrl emits a signal). If the current is uniform but the boat changes direction even in this case you will notice a change and this is the equivalent of the compass effect. For this reason, I think it is very difficult to increase the sensitivity for a buried metal but not for the compass effect.