Andy Flind MFD.

[abdou2014]

Between the preamp and The Amplifier IC1, what are the changes for (C1 - R3) ?

[Geo]

Between the preamp and The Amplifier IC1, what are the changes for (C1 - R3) ?

Make C1= 47n and connect a resistor 1M between pin2 and ground (IC1a)

[abdou2014]

I'm designing the circuit board . Thanks for your help

[abdou2014]

For the coil I think a big inductor is more sensitive except that it may react to interferences,

what is the best Coil for this device ?

[Mike(Mont)]

Happy Birthday Geo!

Looks interesting enough to experiment with.

[GOLDEN LILLY]

Hi folks, I build an lrl based on the original schematic of Andy with some modification that is more sensitive and directional. Pre-amp is still used, values of the components like capacitors and resistors are changed, audio stage are also changed, Ic's are also changed which make this lrl very reliable to use.

[abdou2014]

That's what I'm doing, you want to help or scare ???

[Geo]

In place of speaker you can use a beep generator.

[abdou2014]

we connect the audio output directly in the 555, or we add 100nF + transistor between two

resistor 680K ?

[Geo]

Do you have the schematic of Alonso's PD???

[Geo]

Happy Birthday Geo!

Thanks Mike and Sneshko

[abdou2014]

We have to change nothing in the original diagram except C1 - R3, you confirmed ?

[abdou2014]

I think (mineoro special series 2000 and Iconos md) are prototipe Andy flind modified ?

[Geo]

I think (mineoro special series 2000 and Iconos md) are prototipe Andy flind modified ?

No....
I asked you if you have shematic of PD????

[Geo]

We have to change nothing in the original diagram except C1 - R3, you confirmed ?

you will see on the way...
It is better to make a pcb only for beep generator and another one for coil preampl.
Also it is better to use different power supply for beep generator and for preampl.
Only you will see the problems and what mods to make...