Quote:
Originally Posted by nelson
Ok thanks J_Player.
THats very clear.
So, what kind of transmiter we must uso to work with gold gun?
Could an AM VLF trnsmitter do the job?
Thanks
Nelson
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Hi Nelson.
A simple oscillator which produces a sine wave can be connected to a loop.
No modulation is needed. A pair of transistors are capable of producing a wave form close enough to a sine wave for this purpose.
You don't need more than 50mw power to cover a large treasure hunting area.
The loop can be small like a metal detector, or large - maybe 1 meter diameter or more.
You can even make a large loop of cable that you lay on the ground like geologists do with their VLF transmitters.
My preference would probably be a 1 meter loop that I can set to the side of the treasure hunting field.
If I did not get good results, then maybe I would lay a 100 meter diameter cable on the ground and connect the ends to the oscillator.
Set the transmitter to your favorite VLF frequency.
This can be anywhere between 5KHz to 150KHz.
You will see that lower frequencies can penetrate deeper into the ground.
(5 KHz has been used to send communications signals more than 50 meters below the surface).
The problem with lower VLF frequencies is they are not as good for pinpointing a location as higher frequencies.
This is why we hear people using frequencies between 60 and 120 KHz - because it can locate small anomalies more precisely than lower frequencies can.
The higher frequencies do not penetrate as well into the ground, but at 120 HKz you can expect to penetrate at least 2 meters in most soil.
This is probably a good range of depth where you will want to find most of your treasures.
At 50-60 KHz you should find nearly double this amount of ground penetration.
Just remember that wet and conductive ground does not allow RF to penetrate as well as dry and non-conductive ground.
Also, keep in mind that after you choose your favorite frequency, you must calibrate the gold gun to the same frequency as the transmitter.
The gold gun must be able to receive the transmitter signal before it can tell you what direction the transmitter anomalies are coming from.
You may want to use very stable capacitors in your transmitter oscillator and receiver circuits in order to keep the frequencies stable.
If you have trouble keeping tuned to the correct frequency, you could add a trimmer capacitor in the gold gun to make tuning adjustments while you are treasure hunting.
Finally, do not be disappointed if you find the gold gun does not help you to locate buried metal.
This is what most people reported who tried it.
Best wishes,
J_P