Quote:
Originally Posted by Anwar2
thanks man and Iadjust the coils placment ( small coil RX ) its detects metals But the distance Im not agree with it may be I used ceramic capasitors for the coils because the mica not availabe in the market here in Dubai
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Hi Anwar2,
The Mica capacitors have only one advantage.
Mica capacitors are very stable when the temperature changes.
When you use Mica capacitors, the frequency will not change when the temperature changes.
If you can see the TX and RX are at the same frequency, then you should be able to find good tuning with the null control and the sensitivity control, even if they are not Mica capacitors.
But if the TX frequency is different than the RX frequency, then you should make adjustments to make these two frequencies the same.
This can be done by changing the coil capacitors, or by changing the turns on one of the coils until both the TX and RX are the same frequency. (best to change the capacitance to make same frequency).
You can look here to find the method for tuning after the frequencies are the same for TX and RX:
http://www.longrangelocators.com/for...8&postcount=59
This circuit is only for the original factory circuit that was designed for short range detection.
It is the exact circuit that was found in the locator that the factory sold more than 40 years ago.
The range for detection was originally less than 1/2 meter when the factory sold these detector kits.
But many experimenters say they find longer detection range after they make modifications to the circuit.
I do not know exactly what modifications these experimenters make to find longer range detection.
Maybe some LRL experimenters can show what modifications are needed to find long range detection from this circuit.
Best wishes,
J_P