IGSL

[Daxxin]

Opss yes you are right its opposit polarization ..tanks Davor , i am not expert in electronics at all just was watching at this chip UFDC-1 or 1M , cheaper and easy to use for hobbist
its 2x14 dil socket , seems can do a lot of measurements and 3 types of comunication UART,SPI and I2C , since measuring also phase shift,Frequency,Period, Frequency differenceetc..etc can be useful to made some sort of VDI?
http://www.sensorsportal.com/HTML/E-...S_4/UFDC_1.htm

[Davor]

It would have to go into the front-end of a rig to use various frequency related measurements. Point with VLF IB detectors is that once you convert the Rx signal to the baseband, you are able to apply motion compensation and ground balance, thus exaggerating target response by several orders of magnitude. A phase meter can be useful for tuning a coil, but not as a key component of a detector, and unfortunately not as a VDI. At least not directly.

@zoomix, thanks, a nice one.

[zoomix]

It would have to go into the front-end of a rig to use various frequency related measurements. Point with VLF IB detectors is that once you convert the Rx signal to the baseband, you are able to apply motion compensation and ground balance, thus exaggerating target response by several orders of magnitude. A phase meter can be useful for tuning a coil, but not as a key component of a detector, and unfortunately not as a VDI. At least not directly.

@zoomix, thanks, a nice one.

Hi Davor,
anglais


français


arabe



Alpha

Hello Davor,

I post this track because I use it only as a tool for phasing coils.

For those who do not have a 2-channel oscilloscope.

To adjust the phase coils is not good?

[ivconic]

here is a video from my IGSL Musketeer with selfmade Coil. My Values for the RX= 14,16 mH and for TX= 1,03 mH. I have replaced the capacitors on RX side against 18,3 nF

https://www.youtube.com/watch?v=7sSDuTmsTLA

I pull tape ring is detected in 38 cm .... and a 25 öre silver coin in 30-31 cm

Firebox, i just watched this video:

https://www.youtube.com/watch?v=XcOV-fA1ass

Looking it, and looking previous one i am bit confused.
You said it is after you applied mods (bipolars and pin swapping).
So, i am interested to know if there was difference in behavior with original setup and later with second one?
Have you noticed any differences?
What differences?
Your observations are valuable for me and my future work on IGSL.
One more thing;
air distance on Al pull tab is quite good and audio response is quite right with proper tone pitch.
Yet, somewhere in the middle of video clip; you tested it with iron bar, right?
So it gave proper audio pitch on iron bar only at 1/3 of previously achieved distance with pull tab?
Above that distance it started to mix audio pitches and tends to produce wrong one (higher pitch on iron bar?)
Am i right? Maybe i misunderstood it's behavior watching a clip?
In case i am not wrong; than something is not good there yet.
I am interested in differences between original IGSL setup and later Davor's mod?
Also i would like to hear clarifications about behavior on that iron bar detection too.
Many thanks in advance!
Cheers!

[Altair]

Today I am gone out with my IGSL and I have found!!!, great machine!!!
When was time to go back I have put for a while the MD in touch back the car and I am start to go!!! after one hour, arrived at home... hargggg!!!
After a while I have realized what I made; the IGSL was left on a little street in the wood. I am no words to describe what I have proved.
Immediately but without hope, I came back to the little street in the wood: after two hours nobody has found it, Yeah, what a lucky man I am!

Sorry but I needed to share my joy!

[Qiaozhi]

Today I am gone out with my IGSL and I have found!!!, great machine!!!
When was time to go back I have put for a while the MD in touch back the car and I am start to go!!! after one hour, arrived at home... hargggg!!!
After a while I have realized what I made; the IGSL was left on a little street in the wood. I am no words to describe what I have proved.
Immediately but without hope, I came back to the little street in the wood: after two hours nobody has found it, Yeah, what a lucky man I am!

Sorry but I needed to share my joy!

You were very lucky!

[Firebox]

Firebox, i just watched this video:

https://www.youtube.com/watch?v=XcOV-fA1ass

Looking it, and looking previous one i am bit confused.
You said it is after you applied mods (bipolars and pin swapping).
So, i am interested to know if there was difference in behavior with original setup and later with second one?
Have you noticed any differences?
What differences?
Your observations are valuable for me and my future work on IGSL.
One more thing;
air distance on Al pull tab is quite good and audio response is quite right with proper tone pitch.
Yet, somewhere in the middle of video clip; you tested it with iron bar, right?
So it gave proper audio pitch on iron bar only at 1/3 of previously achieved distance with pull tab?
Above that distance it started to mix audio pitches and tends to produce wrong one (higher pitch on iron bar?)
Am i right? Maybe i misunderstood it's behavior watching a clip?
In case i am not wrong; than something is not good there yet.
I am interested in differences between original IGSL setup and later Davor's mod?
Also i would like to hear clarifications about behavior on that iron bar detection too.
Many thanks in advance!
Cheers!

Hi Ivonic,

i have build the IGSL based on your schematic (with normal electrical Capacitors side by side instead bipolar one). After I have finished the igsl, the FE Channel was working good, only the Iron depth was very, very poor.
User @ DAVOR here from Geotechforum said it could be the wrong working iron channel and I should do the pin-swap Mod.

So I have made the pin swap carried out according to the instructions, and at the same time I also replaces the normal capacitors against Bipolar one.
Now it seemed as the pin swap would have given the IGSL a higher search depth, but in reality it was the exchange against the bipolar capacitors.

The only changes I´ve made was installing the bipolar capacitors against the electrical one, and my self-built search coil .....currently my IGSL detects Iron very bad, but the non-ferrous channels works very impressive. So, that’s all …..

It seems to me like a part of the iron channel is working in the non-Ferrous channel :o) but it´s ok for me, because I am searching for Silver and Gold, not for Iron :o))

Regards


Firebox

[Davor]

The whole point of pin swap is to prevent the Fe channel to activate prematurely and while detecting Non-Fe targets. Additionally it perfects the overlapping discrimination of targets that fall between Fe and real coloured metals, effectively giving you a precise "third" tone over a wide span of target sizes and distances. It does not affect Fe sensitivity in any way. In fact it enables you to use a common Disc. Sens potentiometer.

I found a bit cleaner way of applying the pin swap. It is found at http://www.runoffgroove.com/6949.html

and it looks like this (this is an example of the way it is done, not the actual IGSL pin swap):

[der_fisherman]

The whole point of pin swap is to prevent the Fe channel to activate prematurely and while detecting Non-Fe targets. Additionally it perfects the overlapping discrimination of targets that fall between Fe and real coloured metals, effectively giving you a precise "third" tone over a wide span of target sizes and distances. It does not affect Fe sensitivity in any way. In fact it enables you to use a common Disc. Sens potentiometer.

I found a bit cleaner way of applying the pin swap. It is found at http://www.runoffgroove.com/6949.html

and it looks like this (this is an example of the way it is done, not the actual IGSL pin swap):

That appears to NOT changeover the two pins......I get the principle and I would use insulated wire if I was doing it on at least one of the two connections....
Regards
Andy

[Altair]

Hi Ivonic,

i have build the IGSL based on your schematic (with normal electrical Capacitors side by side instead bipolar one). After I have finished the igsl, the FE Channel was working good, only the Iron depth was very, very poor.
User @ DAVOR here from Geotechforum said it could be the wrong working iron channel and I should do the pin-swap Mod.

So I have made the pin swap carried out according to the instructions, and at the same time I also replaces the normal capacitors against Bipolar one.
Now it seemed as the pin swap would have given the IGSL a higher search depth, but in reality it was the exchange against the bipolar capacitors.

The only changes I´ve made was installing the bipolar capacitors against the electrical one, and my self-built search coil .....currently my IGSL detects Iron very bad, but the non-ferrous channels works very impressive. So, that’s all …..

It seems to me like a part of the iron channel is working in the non-Ferrous channel :o) but it´s ok for me, because I am searching for Silver and Gold, not for Iron :o))

Regards


Firebox

I think that the behaviour of your IGSL is strictly caused by the TX/RX phase difference. This is for how the coil was constructed.
In my coil phase difference is very minimal and at first beginning the MD gave me a good result for Non Fe channel but a strange behaviour for the Fe one. Then I have made the modify of swapping described in my post #1646; with it Fe channel is working fine.

This is my phase relationship, I would like to see that of your coil, if is possible. I am very curious.

[mschmahl]

This is my phase relationship. The bigger curve is TX the smaller RX. It is with a Minelab-Explorer DD-Coil.

[Davor]

This looks a bit too much shifted. Perhaps the Rx coil is too close to resonance?

[Davor]

@didier pointed me to a mistake in a schematic with my mods. It happened by dragging a component in ExpressSCH, and incidentally the connection was made at a wrong pin of U8b, here is a picture of the error, and a corrected schematic.

[Firebox]

I think that the behaviour of your IGSL is strictly caused by the TX/RX phase difference. This is for how the coil was constructed.
In my coil phase difference is very minimal and at first beginning the MD gave me a good result for Non Fe channel but a strange behaviour for the Fe one. Then I have made the modify of swapping described in my post #1646; with it Fe channel is working fine.

This is my phase relationship, I would like to see that of your coil, if is possible. I am very curious.

[ATTACH]23116[/ATTACH]

Hi Altair,

here my sinuswaves from my IGSL Musketeer! The upper wave is TX and the lower wave is RX. On TX i use a 330nF and on Rx side 15nF

Regards
Firebox

[Altair]

Hi Altair,

here my sinuswaves from my IGSL Musketeer! The upper wave is TX and the lower wave is RX. On TX i use a 330nF and on Rx side 15nF

Regards
Firebox

Thank you for sharing your picture.
It seems a phase relationship pretty normal, so I don't explain myself your results; it could be some technical constructive (shielding, etc..) that make difference.

@ mschmahl:
Is your DD coil an original MB one?