IGSL

[Davor]

Aside from my mods the design is shown at the beginning of this topic.
As for the depth, it will be some ~20cm for a small gold coin, same as several other builds around. But the best feature with IGSL is that you have 2 discriminators providing you with 2 tones, and you can set them to overlap and give clear indication for poor conductors, such as aluminium foil, nickels, or nowadays steel cored rubbish coins.
This two tone feature is extremely useful at junk infested fields with aluminium foil, and steel (tin) cans. Point is that steel and Iron have orientational response at different axis than the coloured metal plating, and you get a tell-tale deeh-dah sound when passing over such items, while you have a clear tone on pure metals. No single tone detector can do this.

[danev]

Hello everyone!
I have interesting: the "father Ivica", no longer looks to the page of his creation?

[Davor]

I think he is finally in a detectorist's paradise. So am I. We both had a looooong winter with loooooots of snow, and we finally have some nice weather. So give him a month or two to recuperate.

IGSL is live and kickin' and I may have some news soon. Again only minor changes on the existing layout with significant impact on functionality.

[Davor]

How about a beach seeking GB mod for IGSL? Any interest?

[woodbob123]

yes lot's from me

[golfnut]

My expectation of IGSL was fairly high I recall.

I dont detect a lot as its hard to get UK permission from land owners - when I did with IGSL on inland farms it gave lots of high and low tones together.
Large iron or medium small iron with thick rust gave both tones and left me with indescision. Curiosity would take over and you begin mining.
All too often rusty iron. It was like going to the gym with a shovel !



Personally I can just about get my head around a more simple machine with 1 tone.
With practise the sound and duration of the tone can give you a feel for the size and material of target.


Iron - Depends on disc setting
1 Full bam-bam tone - Disc open - large or medium iron
2 short clipped tone (often in one direction only) for small rusty iron - Disc just leaving iron behind
3 nothing, Disc just off iron.

Non Fe
1 a tone, not pure, but not clipped, not great location to dead centre of coil. often crushed ally can
2 fairly punchy tone, relatively loud, good centre of coil, - lead peices, roman brooches
3 medium volume, clear sweet ringing tone, good accurate location to coil centre - older coins, bronze or silver etc.
4 weak tone, a little broken, - often thin corroded brass e.g. thimble
5 loud, pure, booming tone - gold ring e.g. wedding band

Finds and tones I have found with my IDX (no VDI)

S

[danev]

I think he is finally in a detectorist's paradise. So am I.

I think you're absolutely right and Ivica now is exactly there. Ivica! Take me with you!
But he might look to us sometimes.

Davor. If you aren't hard, tell us more about your revisions of the PCB.

[Davor]

So far I did not make any PCB revisions. The only revision I'd be very happy with would be a pin swap for discrimination, as it is quite difficult to make it properly ikenbana-style. All my mods so far are either omitting components, replacing the potentiometer functions, or modding values. It is a bit more "nervous" than the original, but it has joined Sens. control, and effective volume control. I also joined the ground balance into a joint GB control, so in effect I have one channel to spare - that's where I see potential for improving this rig into a real beach seeking one.

To have an effective GB for salty beaches you need a separate all metal channel fixedly adjusted to cancel ferrites. This way the discrimination remains precise on difficult soils. "Normal" metal detectors have one and the same channel for all metal and GB, which is fine for "normal" soils, but not so much for salty beaches where proper GB position moves away from ferrite response, while All metal response should remain aligned to zero on ferrites.

So the concept is actually quite simple, two discrimination channels and one GB channel - turned to fixed all metal - are used to set the discrimination criteria, while the remaining GB channel resumes the GB function and is given extended tuning range.

My situation is that I hunt salty beaches with terra rossa on the shore, and it means that my GB response is somewhere in between salts and ferrites, so I can't settle for either/or GB choice, but a full 90° range.

I'm about to make a fully automatic GB tuner for my other project, but it is unlikely that it will be finished during 2013, so this full range manual GB for IGSL will serve as a learning platform, and hopefully as an improvement of IGSL.


@golfnut, I adopted a fairly simple tuning procedure for IGSL GB and discrimination that works perfectly for me. GB is tuned by bobbing a coil, no surprise there, but to tune discrimination I use a hank of aluminium foil that I throw on the ground. Then I tune Fe and Cu channels so that they barely overlap at foil. It works as magic. For foil I get a "pure" double tone, but for galvanised materials, such as tin cans, beer caps and nowadays junk money with iron core I get two tones in a sequence, as the iron response is strongly directional. That way I have a fairly good idea what's there. Only garbage I can't determine (as junk) are the aluminium cans, but other rigs are not any better at that either.

[golfnut]

"@golfnut, I adopted a fairly simple tuning procedure for IGSL GB and discrimination that works perfectly for me. GB is tuned by bobbing a coil, no surprise there, but to tune discrimination I use a hank of aluminium foil that I throw on the ground. Then I tune Fe and Cu channels so that they barely overlap at foil. It works as magic. For foil I get a "pure" double tone, but for galvanised materials, such as tin cans, beer caps and nowadays junk money with iron core I get two tones in a sequence, as the iron response is strongly directional. That way I have a fairly good idea what's there. Only garbage I can't determine (as junk) are the aluminium cans, but other rigs are not any better at that either."

Im glad it works for you and you found a neat cal routine.
I could revisit mine at somepoint and re learn it and persevere. I just got bored digging all the iron.

Currently my IDX is exactly the same depth and descrimination as a Tesoro/Laser Trident II and is finding me some things. I spend most of my fiddling time on coils currently.

recent IDX finds..


S

[liekwang]

firebok what you can give me kah scema are you doing and networks and all kinds of PCB board components thanks

[Davor]

You can check silverdog's web shop for PCBs.

[liekwang]

davor

?Thanks davor for his info davor if you can provide me the layout its FCB.ISGL thanks again

[Davor]

You can find two versions of IGSL. More popular is a version optimised for Musketeer coils. You can build your own coil, as most people did. I also did some mods to make it discriminate iron more accurately, and to make it faster. PCB layout file of this version is attached...

[liekwang]

thank you for his help davor but I can not see the zip file types there whether kind pdf or png once again thank davor

[der_fisherman]

Help with .zip files

Two of the files purport to be Eagle files ( a good CAD program to use and many years in development. A free full version is always available for Hobbyists to download and use). These two files were not in a true Eagle format according to my Eagle. e.g. unusable.
The third is simply a .jpeg of the circuit diagram which I attach.
regards
Andy