IDX-PRO+VDI

[Ropcsika]

[ATTACH]21394[/ATTACH][ATTACH]21395[/ATTACH][ATTACH]21396[/ATTACH]

Nice job

[Schatztaucher]

[golfnut]

Mod

I did a mod to my IDX last night. Not very scientific but here goes.


The Tx osc on mine is at 11KHz ~0.44mH L and 470nF cap I wanted to see if there was any room for more Tx signal without problems in use or circuitry fails.

I use 3 Li Fe laptop cells 1.8Ah 12V.

I wanted to freshen the Tx drive a little, I cut the trace feeding R7,8,9 and added a wire to the regulator input. So Tx rail is 4v higher now.



In quick test it does give me a refreshingly clear positive ID on a uk 20p at 8 inches - under my lawn. - previoulsly I struggled with this testbed target.

More easy to use than deeper - more crisp and positive somehow - and it didnt go bang !

I also found the point on the Disc dial where coke is rejected and non Fe items still ring out..

Will try later on farm.

S

[ahmad]

?????????????

[ahmad]

can i make a bigger search coil for idx pro? whats the setting and measurements? thanks

[golfnut]

I had recently good experiance with my IDX. I had my Rx coil wired correctly - prior to Nulling. - PP was fine, all good.



Having fine tuned the null and potted - I never re-checked it. It must mave flipped the other way during nulling.

Anyway my PP was toilet and I got loads of Iron beeps and a double for targets.

Flipped the other way and the Iron is controllable exept for big iron.


I thought my Threshold did nothing - but it does.

I added a series resistor in with my GEB pot to get more range.


Got a small Edward II hammered penny from about 1300AD on sunday heavily clipped coin.

A spark plug from 1919 designed for Model T in Birmingham UK (Apollo brand)

USAF 1/2" B52 cannon round cut in half by plough - I had to empty the cordite! _ It was all in my pocket.

George 3rd Penny 1806 , buttons, lead shot. I will post pic of my scrappy finds with the IDX over the last 4 weeks.

S

[Schatztaucher]

hello friends soldering,
the board of silverdog I will handle clean and only once solder. So should all the right parts the first time purely leg. processed can someone tell me which is the better version for P5 ...... in one layout is a 10kohm, and other times a 100kohm poti....

regards

[Davor]

...But if coil leads are reversed than i would expect double tone wit short pause in between, of course.

I'm suggesting that right now you have a double tone situation with non-reversed coil leads because a pinpoint has phase reversed against the GEB phase, and in my logic they'd have to be in phase.

It seem to me that the pinpoint channel in IDX is not much of a feature, so I'd better stick to my slow motion compensation instead - makes things more straightforward.

[satdaveuk]

On the Whites DFX when in pinpoint mode the frequency gets higher as you get closer to the target while still decodeing target id incl depth and ground reading on the vdi display , typical silver old sixpence 8"-10" deep you can dig a 4" round hole and you will find your target bang centre of the coil everytime, anything after 10" in typical uk soil the hole needs to be larger in diameter.
Just letting you know what is possible, and what we are not getting with are projects todate because are designes are a little pre-dated, wish we could get hold of some more modern circuits to ponder over.

Just thought id put my 2 pennys worth in

[ivconic]

Nope, the best discrimination is by my IGSL, period.Even though it is a slow motion all metal channel, it still abides by the rules of the coil geometry, so swinging a coil while in pinpoint mode should give off some tonal representation of the target. Continuous tone is just an indication of misalignment of a bias, and it should barely scratch from silence to be perfectly set.
So again, when you swing a coil while in pinpoint mode, do you get a single or a double beep? My guess is that you get a double beep because of the wrong phase.

BTW, I thought of turning my IGSL into a slow motion compensated one. Even now I get a meaningful reading when swinging slowly, but it can do even slower. Pinpointer? I don't need one.

I understand now.
It is always single tone and difference is only in lasting and volume. Closer target = longer lasting&louder. Distant target = shorter lasting&quietly.
But if coil leads are reversed than i would expect double tone wit short pause in between, of course.

[Davor]

Nope, the best discrimination is by my IGSL, period.

...i don't understand what are you meaning by " minimum in a middle" ?
As signal rises, tone rises too, if that's what you mean?

Even though it is a slow motion all metal channel, it still abides by the rules of the coil geometry, so swinging a coil while in pinpoint mode should give off some tonal representation of the target. Continuous tone is just an indication of misalignment of a bias, and it should barely scratch from silence to be perfectly set.
So again, when you swing a coil while in pinpoint mode, do you get a single or a double beep? My guess is that you get a double beep because of the wrong phase.

BTW, I thought of turning my IGSL into a slow motion compensated one. Even now I get a meaningful reading when swinging slowly, but it can do even slower. Pinpointer? I don't need one.

[scs]

The best tone discrimination is made with 2 GND channel and 1 discrimination channel.

[golfnut]

The PP on mine is sileuntil I put the sens pot to half way and I get tone.

It is a little sluggish to respond over target as this is not a dc coupled channel!



It has a cap in it and as such is still a motion mode.

Make C16 a 10u non polarised for more non motion / motion sens?

ps I will try swapping the Rx leads - yes sens may suffer on being reversed - but the savior is the double beep tells you its non Fe!


S

[ivconic]

I am aware of the continuous tone, but even that one has some highs and lows, and I just wonder where they are. My humble guess is that there is a minimum in a middle, and I wish to confirm that. I'm considering using a spare GEB channel in my IGSL for the same purpose, and I really wish to see this pinpointer in action.

BTW, this design, same as TGSLIGSL has somewhat odd compression by my standards. Given more symmetry it would reduce masking. My modded IGSL gives distinctive non-Fe beeps for each of the brass bolts on an old rusty knife, and that says something.

You bet it says something!
You discovered now why i decided to leave TGSL and make IGSL instead!
Exactly just because of the same damn masking problem as IDX is having too.
My approach is kind a odd, i admit.
Instead trying to make it with full wave demodulator i picked another approach.
What i want to say: IGSL should act as you are describing, that was the point.
Mixing various positions of those two Disc potentiometers you should be able to get exactly what you are explaining.

"..I am aware of the continuous tone, but even that one has some highs and lows, and I just wonder where they are. My humble guess is that there is a minimum in a middle, and I wish to confirm that..."

Yes, it is nonmotion, continuous tone, affected and adjustable by Treshold command. But i don't understand what are you meaning by " minimum in a middle" ?
As signal rises, tone rises too, if that's what you mean?

[Davor]

I am aware of the continuous tone, but even that one has some highs and lows, and I just wonder where they are. My humble guess is that there is a minimum in a middle, and I wish to confirm that. I'm considering using a spare GEB channel in my IGSL for the same purpose, and I really wish to see this pinpointer in action.

BTW, this design, same as TGSLIGSL has somewhat odd compression by my standards. Given more symmetry it would reduce masking. My modded IGSL gives distinctive non-Fe beeps for each of the brass bolts on an old rusty knife, and that says something.