Andy Flind MFD.

[Geo]

Yes but it must detect the quartz watch....

[abdou2014]

Does this LRL have the ability to detect a test field 1 year old ?

[Geo]

I don't know.
some years ago i tried an cryfton at a ancient place (where some other lrls gives signals) without results.
Also with my mfd i found some very small objects but nothing else....

[abdou2014]

What are the changes that increases the sensitivity , I can not detect a watch ?

[Geo]

Maybe you have bad calibration or bad preamplifier...

[abdou2014]

I do not think everything is OK, preamp first 2N2222 and the second bc238 HFE 700. I noticed: when I leave the first LED on, and I adjust the buzzer Off, the LRL more sensitive than all LEDs off . I need help Mr Geo!

[Geo]

Can you give details of coil and frequency???
do you have potentiometer at preampl output??

[abdou2014]

[abdou2014]

Coil 2X30 turns + Pot 5K pream .

[Geo]

Coil 2X30 turns + Pot 5K pream .

What do you mean 2x30???

[abdou2014]

Like This .

[ASHIL]

ANDY WITH DIGITAL DISPLAY

Hi My friend
Can you put this circuit and digital Display`s in here? But if not Personal

[Geo]

Like This .

Why you use 2 coils????

Who is the coils diameter??

[abdou2014]

The diameter of the coil is 16 cm. with 30 turns I detect the transmitter at 1 meter, 2X30 I detect at 2 meters . frequency 80 Khz .if it's wrong what's to change ???

[Geo]

I don't know more....
Now about calibration you must calibrate it so the first led to be on (light) and just little before the 2nd led turn on.