The following feature reports on some fascinating findings I originally discovered during the period 1990 to 1993. My investigation is far from conclusive, but should give some direction for future research to be carried out.
The basic electrical circuit consists of a very high gain amplifier driving a frequency generator which in turn drives a digit counter.
A retractable aerial picks up minute amounts of current flow (in the order of 50 microAmps) to trigger the frequency generator. The frequency of any current detected is then converted into a graphical display via a row of ten light emitting diodes (LED's) As the LED's are driven from the counter, the frequency of LED flashing is roughly a tenth of the detected frequency. It is roughly this because a variable resistor allows you to alter the base frequency of the oscillator. This allows you to compensate for very high frequencies that may be picked up.
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I originally developed the gadget whilst experimenting with some electronic components. It seemed to pick up weak electrical currents, such as those surrounding light switches and cables etc. I initially thought that it would be handy to detect electricity flowing in cables hidden within the walls of my house.
I happened to take the gadget to my parents house where my mother, who is also interested in Corn Circles, suggested I tried testing some ears of corn that she had collected two or three days previously and had hanging to dry out in the kitchen.
I tested the gadget and found that some ears of corn gave a strong reading (indicating electrical current flow) and some gave no reading at all (seeming to be 'earthed' or discharged of energy). My mother then told me that some came from inside Corn Circles and some came from outside. The ones from inside the circle having given no reading on my gadget. These results were repeatable 100% using the corn samples collected by my mother. This made me very interested to see if there was a definite way of telling 'genuine' Corn Circles from non-genuine ones as man made circles, formed by trampling corn gave readings identical to the surrounding unflattened 'normal' corn.
I later improved the gadget, equipping it with a better aerial and a more sensitive amplifier circuit.
In practice, the gadget indicated electrical current flow in plants and living matter, including humans. However, in 'genuine' Corn Circles (as opposed to human made ones) there was a complete lack of energy almost as if whatever was making the corn circles had 'earthed' them.
From experience, I judged the following table of results, based purely on the results of my crop circle tester.
Whilst surveying the Alton Barnes Snail formation (affectionately called 'Brian' by local circle researchers) on the night of Sat 15th Aug 1992, I felt a strange tingling sensation down my back, from my neck to the base of my spine. I have never felt any physical feelings before inside crop formations and I was feeling perfectly healthy at the time. The time was approximately 10.00pm and the weather was fine. in fact the atmosphere felt 'charged'.
Whilst testing the corn inside Brian, a very powerful 'overload' state was detected. This seemed in contradiction to normal 'genuine' readings of no signal. The frequency detected seemed to be steadily rising whilst we were actually inside the formation. After a few moments it had risen to beyond audible range. The batteries in the gadget were also drained in a matter of 10-15 minutes. They should last around a year given normal usage.
On further surveying the following morning, the formation had returned to normal readings, ie. no signal inside the circle and a reading in standing and flattened corn outside the formation.
N.B. The gadget is not affected by wind flattened corn, which gives a reading the same as for normal healthy standing corn. This was tested on a number of separate occasions.
It seems that whatever is making the corn circles is draining electrical energy away from corn inside the formation. It is as if the corn has been 'earthed'. The moisture level of the corn seems to affect the readings slightly, which could be an area for circuit improvement. However, both control and circle samples are affected by equal proportions so moisture level does not have a negative effect on readings. A future improvement could be the addition of a frequency meter to measure the actual frequency being picked up, which seems to be around the 4-5kHz range.