Tribute to Andy Flind

[Esteban]

New design

[Geo]

You don't need to use hundreds bronze and nickel coins. Maybe 20 is OK, but better as Volta battery disposition. You can use transparent common tape for paper for to keep the form and it will not move when is bury. 20-25 cm depth is OK.

http://www.geotech1.com/forums/showthread.php?t=15408

Thank you Esteban.
With "Volta battery disposition" do you mean each coin on the other.... one bronze, one nicel ... etc???

Regards

[Geo]

New design

What LRL is this???? Is the MFD in new box??? Did you test it??

Regards

[Geo]

geo: for experence, in lrl, very thickness wire is most sensitive, but unstable, not thicknes is less sensitive but stable, coil big is stable, coil little less stable, oval coil discriminate major, square coil is good for put out noises, stable, coil glued is stable coil not glued very unstable to vibrations or warm, coil inside wood is good, whit paint white, coil inside black plastic unstable etc coper aleate hard good for tx coper soft good for rx etc, lrl is minuciosa science
lrl isnt for standar people without patiente, is for obsesive builders
lrl is science whit very much distincts metod, what is major? simple is major

Thanks...

[Geo]

Hi Geo
Your receive coil is induction balanced ? Or it's a single turn coil and then it's a sort of antenna ? In my instrument I can detect positive signals with green led and a beep and negative signals with a blue led and no beep. Trees and walls cause negative signals. Perhaps I have to realize a sort of discrimination or ground exclude but my test with a synchronous demodulator or a phase comparator it reveals no phase change between trees and my charged plastic rod. I think that it'is no a great disadvantage the sensibility to trees and walls if I am almost 1 meter away.

Best Regards

Hi FrancoItaly.
No my coil was a simple mono coil connected at the output of a oscillator. If i tune exactly at the center of frequency then i have "negative and positive" signals, or signal from up and down carrier side. I let it because it was very sensitive at people... trees ... stones... but NOT at buried objects

Regards

[Geo]

New design

Hi Esteban.
Why you have the coil in the center of box??? are you use coil stimulator???
Also why so long distance between coil and detector???
Is this coil a loop with transformer??
If yes what about the transformer? is it the same 1.8 ... 2 Ohm??

Regards

[FrancoItaly]

Hi Geo
Where is connected your RX stage if there isn't a receive coil ?

Best Regards

[Geo]

Hi FrancoItaly.
I spoke for post#39. Are you continue to mean for this of for the new.
If you mean the old one, no Rx stage !!!!

Regards

[Esteban]

Hi Esteban.
Why you have the coil in the center of box??? are you use coil stimulator???
Also why so long distance between coil and detector???
Is this coil a loop with transformer??
If yes what about the transformer? is it the same 1.8 ... 2 Ohm??

Regards

No stimulator. Distance is only 12 cm to the box. Is simple coil, no transformer.

Regards

[FrancoItaly]

Hi Geo
Excuses me, in my post #43 I referred to your instrument at 135 Khz with a receive coil, with a gain of 1000 it's necessary to balanced the receive coil, or the receive coil it is made vwith few turns.

Best Regards

[FrancoItaly]

Hi Esteban
Can you tell me if your lrls are also sensible to trees and stones ?
Best Regards

[FrancoItaly]

Hi All
In my instrument at 135 Khz I use in the receiver stage this circuit with very high impedance input. The 2 diodes replace resistors great then 100M that are difficult to find. Perhaps the 10M resistor is not necessary but I had this already soldered in the pcb...the OP can be used as amplifier not only buffer.

Best Regards

[Esteban]

Thank you Esteban.
With "Volta battery disposition" do you mean each coin on the other.... one bronze, one nicel ... etc???

Regards

Maybe can be good... I only use bronze small coins.

[Esteban]

Hi Esteban
Can you tell me if your lrls are also sensible to trees and stones ?
Best Regards

No, because don't use transmitter, is pure receiver.

[detectoman]

hello stevan my congratulations for these new lrl, i too understand what presence near of circuit and coil cause any indesable effect of funcionability, good stratege of you for most efficience, is beauty the design, seems how jirafe, what features have this cacharro stevan?