IDX-PRO+VDI

[golfnut]

I dony know of any errors on the pcbs

[der_fisherman]

Silver dollar makes a good point..

With metallised foils we have these very close

With graphite it is a ways off the coil


This may be a significant difference

That is a big difference, if you think about it we usually shield each coil except for a small gap, with the graphite its one shield for both coils.

Does it even have a gap?

Is one needed?

Does the distance do anything good or bad?

Some "heavy " questions........but really important.

This could prove to be the one single most important IB question that we need to understand & solve.

Regards

Andy

[zoomix]

I set up my IDX as follows:
1) set up P7 in approximately middle position;
2) set up ground balance by VR1;
3) moving in the front of coil a piece of aluminum foil and turn VR3, I find the situation where the foil starts discriminating;
4) Turn the 5K pot of VDI-board until a zero reading at approximately the same small piece of aluminum foil.
regards

Hi

I have a little problem with VDI ...

I have a sensing distance of + - 35 cm with an original coil loop 950. GB and dis ok ok

aluminum is discriminated with potentiometer in the middle

I set the VDI with the procedure, but the values are displayed only when the object is very close to the head.

The values are displayed above with raw materials such as copper, steel

If I take a 1 euro coins (nickel, copper and zinc) I must approach the piece coil to have a value.

Does the vdi is disturbed by different metals?

Is it possible to improve this?

thank you

[Koala]

I have a sensing distance of + - 35 cm with an original coil loop 950. GB and dis ok ok

aluminum is discriminated with potentiometer in the middle

Sound like you have fixed your discrimination problem what was the fix


Can't help you with the VDI as I did not bother building one as if it beeps I dig it out


I would expect the VDI to be less reliable the further away the target is seem to remember reading that its only good up to 60-70% of max

"Does the vdi is disturbed by different metals?" can't help here as never tried hopefully someone else will answer for you. Would expect the same reading if the coin is in the same orientation

[zoomix]

Hi koala
Discrimination was a problem because I put a résisante of 470k instead of 4k7. Always recheck
It is the resistance which is in series with the potentiometer of dis. problem solved
Sure that the PCB silverdog contain a short ciruit on the upper part via PCB above U4
my configuration
R27 2M2
R25 150ohm (still in testing)
VR3 out
R43 2K2
2x 1N4148 out

For information, I tested the solution to remove r25 and add 4k7 between 6 and 7 U4 but I lose distance detection.

I hope to have information concerning the reaction of VDI to the same detection distance ..
Is it possible to boost or clean the signal from the inputs X and Y on VDI? or for example take into account the dominant signal for objects alloys ?

Does anyone have the program in Picbasic for VDi?

[Schatztaucher]

F...k, I accidentally soldered a 47k as r57......my mistake!!!! thanks zoomix for inspiration

as far as i now, the VDI is not very sensitive. for me it has an euro in 10 cm distance shown. not realy much......than i make the LUGATEK.
perhaps you try this one.


regards

[ossamaussama]

dose any one try make large coil for idx. for deep big target. like. sonar and deep hunter which is vlf machine

[Koala]

dose any one try make large coil for idx. for deep big target. like. sonar and deep hunter which is vlf machine

1500 Blue Max 15inch coil works well don't know of anyone who has copied it

[paku]

what is difference Old IDX board and New Version of IDX

[golfnut]

the old one had a short because the via diameter on some vias was selected by the pcb manufacturer and they were too large. For most it was OK. But in one place where the via was adjacent to a trace they overlapped and became the same pcb item.

User needed to run a blade thru the copper to make work..

[paku]

witch one is stable on the wet land IDX New version or IDX Old version
i have test 2 idx difference version 1 version have VR3 the version 2 is dont have VR3
my test on the wet land is the very good detection is idx without VR3

is that right

[Koala]

witch one is stable on the wet land IDX New version or IDX Old version
i have test 2 idx difference version 1 version have VR3 the version 2 is dont have VR3
my test on the wet land is the very good detection is idx without VR3

is that right

Not much between them. Some prefer the original others the new. The specification of the components used makes more difference and makes each build slightly different. Just like the factory detectors some run slightly hotter than others even though they are identical.

Sensitivity to wet grass is mostly due to coil shielding. Can also be too much gain.

[paku]

have you test it or that is just theory

[Koala]

have you test it or that is just theory

Tested in the field with two people with two XP Deus running identical program and the same size coil one get a slight signal. Other goes over the same area and it does not register at all.

If your IC's are in sockets you can test it your self by swapping some out and maximizing your detector

On another forum (findmall) Monte was a Tesoro dealer. He use to test every detector. Out of every 10 detectors most would be the same 1 or 2 would run slightly lower and 1 or 2 would run hotter and that does not include the slight differences in coils.


Interestingly I have also tested my IDX with 8" coil on a iffy signal against a Deus with a 9" coil and that also gave an iffy signal.

[konan]

Does anyone know the parameters for concentric colil ?