IGSL

[Davor]

The story: at first power up things does not works well, U1b was self oscillated; so I decided to add a small capacitor to shut down this not wanted wawes! Look at the picture:

This phase shifter operates at high input impedance, and there are wires going to the potentiometer. That's why I woven my wires into braids, but nevertheless, a small 10p capacitor won't hurt anything. I'll check in Spice how much it shifts the phase, but I don't expect to see more than maybe 5 degree.

[Altair]

This phase shifter operates at high input impedance, and there are wires going to the potentiometer. That's why I woven my wires into braids, but nevertheless, a small 10p capacitor won't hurt anything. I'll check in Spice how much it shifts the phase, but I don't expect to see more than maybe 5 degree.

It's true!
Me too woven my wires into braids, in this case it was a braid of about ten centimeters; with add the capacitor no more oscillations occured.

[Altair]

Ok, is time to share some picture of my IGSL:








Coil is home made, handle is from Tesoro Cibola; I hope you like it!

[Davor]

Nah, it is too neat

Any chance we see your rig in action on youtube?

[Altair]

Nah, it is too neat

Any chance we see your rig in action on youtube?

Yes, for sure!
give me some time to prepare the film set!

[Davor]

Don't go fancy, just about any camera will produce a video that can be squeezed into youtube acceptable format by means of virtualdub.

[zoomix]

Hi all,

I remade another coil for IGSL and I also made a "phase meter" to check the phase shift of 20 °

Values finished with shielding coils made in the rules: 6mh TX, RX 6.5 mh

When I measure the frequency of TX, I 14.12 kHz maximum with TR3 and this check by calculation: F0 = 159 / Racine (6x22) = 13.8khz average

My question is why is that the diagram indicates TGSL TX 14.6khz?
For this frequency, I need to change the capacitor C2 20nF ...

By calculation, an TX coil 5.7mh give 14.6khz with a capacitor C2 of 22NF and in this case, why the diagram shows a coil 6mh??

What do you think?

I have another question for those who have set the phase to the oscilloscope:

My phasemeter does not indicate the positive or negative direction of phase shift and that is very sensitive with respect to "0".

When the coils are in phase (0), the phase shift of 20° good will by removing the coils or together?

I'll rephrase my question: when my coils are in phase (coupled +-18mm), I overcoupled or undercoupled from 20°?

I would like to share the pcb for the phasemeter DVM of magazine ELEKTOR. I realize the pcb on "sprint layout" and I think that many people can be interesting. I can put the diagram in this section?

Sorry for my english
Thanks you for your response

[ivconic]

Hi all,

I remade another coil for IGSL and I also made a "phase meter" to check the phase shift of 20 °

Values finished with shielding coils made in the rules: 6mh TX, RX 6.5 mh

When I measure the frequency of TX, I 14.12 kHz maximum with TR3 and this check by calculation: F0 = 159 / Racine (6x22) = 13.8khz average

My question is why is that the diagram indicates TGSL TX 14.6khz?
For this frequency, I need to change the capacitor C2 20nF ...

By calculation, an TX coil 5.7mh give 14.6khz with a capacitor C2 of 22NF and in this case, why the diagram shows a coil 6mh??

What do you think?

I have another question for those who have set the phase to the oscilloscope:

My phasemeter does not indicate the positive or negative direction of phase shift and that is very sensitive with respect to "0".

When the coils are in phase (0), the phase shift of 20° good will by removing the coils or together?

I'll rephrase my question: when my coils are in phase (coupled +-18mm), I overcoupled or undercoupled from 20°?

I would like to share the pcb for the phasemeter DVM of magazine ELEKTOR. I realize the pcb on "sprint layout" and I think that many people can be interesting. I can put the diagram in this section?

Sorry for my english
Thanks you for your response

You are absolutely right.
Original Tesoro coil which i used with my first (prototype) IGSL was ~5.7mH.
And than i measured frequency and noted 14.6kHz on schematic.
Later i assumed that most of people will rather choose to make own coil, 6mH, which is well described in those PDF documents here on forum.
My mistake is because i didn't removed "14.6kHz" from schematic where later i added "6mH" for TX. Sorry!
So 14.6kHz is NOT THE RULE. You don't need to chase it by any cost.
Just set your detector to work good and to meet your expectations, don't mind about exact frequency because IGSL (TGSL) is "tolerant" in wider frequency range.
RX phase is 20 degrees right from TX, meaning it is "overcoupled" (if i understood correctly your terms?).
Use 2 channels scope to see phase relationship while balancing coils.
...
Yes you can post phasemeter schematic here, why not. It can be added to 2 channel scope and used simultaneously in process of balancing.

Cheers!

[ivconic]

Ever since i installed Windows 8 on my pc; i am having troubles to master new Paint which came with!
All my old habits with old Paint wont work with new one!
So i can't make nice corrections on pics.
Anyway, here is pretty ugly and rough "picture" of how phase relationship should look like when observed on scope:

[Qiaozhi]

Ever since i installed Windows 8 on my pc; i am having troubles to master new Paint which came with!
All my old habits with old Paint wont work with new one!
So i can't make nice corrections on pics.
Anyway, here is pretty ugly and rough "picture" of how phase relationship should look like when observed on scope:

Download the free GIMP progam for Windows 8 from here ->
http://www.freenew.net/windows/gimp/68629.htm

[Firebox]

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

[zoomix]

Hello Ivonic,

Thank you for your reply. With the first coil, I change C2 to climb to 14.6khz. Everything worked perfect but when I tested it in my field, it becomes unstable after 5 minutes of use.

I check the phase of the first coil, it is 0.5 ° so it is not good. Yet I measured +-10mV AC on RX and rechecked several times.

Now I'll make the TGSL and I'll check on the new coil and pcb IGSL TGSL.

I'll make a tutorial for the construction and calibration of the phase meter and I'll post here

thank you
zoomix

[ivconic]

Download the free GIMP progam for Windows 8 from here ->
http://www.freenew.net/windows/gimp/68629.htm

Look; that link is giving me "GIMP downloader": small and pretty nasty kind a "downloader" which will for certainly download GIMP executable installation...
BUT ALSO will use "back door" and install pretty nasty DLL which will try to harm system on God knows what way!
Downloader is named "FreeNewDownloader_for_Gimp.exe"!
But i have good secured system which intercepted it and prevented it from a start!
Along with malicious DLL that damn downloader will also suggest installing some other unwanted stuff too.
So what i did?
I stopped it and "pulled out" only Gimp.exe installation. Ther rest is GARBAGE!
Gimp is now installed and working just fine.
First starting lasted an eternity, but second starting is faster and smoother.
Ok i like it. It is powerfull. I will keep it.
But for previous task i would usually use as simplest as possbile software such as Paint.
So i also founded "PaintXP" and installed it! Wow! Now i have good old Paint on Win8 too!
...
Pay attention and avoid any kind of "downloaders" in future, because 99% of those are malicious garbage made by garbage-brained people!
Maybe you didn't noticed what that garbage is doing to your system because you don't have good and clever system protection.
Check presence of "wsk.dll" on your drive and in case you have it: ......ooooahahahahahahahahaah! What else can i say?
I think this is most proper moment for you to switch on Win8!

P.S.
Anyway; thank's for suggestion! I like Gimp and i decided to keep it!

[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

Wow!
Firebox you are beating me just like that with your air distances!!!
Would be splendid if you finish that coil and test it on real soil.
Even if it maintains 80% of those performances - it will be real beast!
Congratulations!

[ivconic]

Hello Ivonic,

Thank you for your reply. With the first coil, I change C2 to climb to 14.6khz. Everything worked perfect but when I tested it in my field, it becomes unstable after 5 minutes of use.

I check the phase of the first coil, it is 0.5 ° so it is not good. Yet I measured +-10mV AC on RX and rechecked several times.

Now I'll make the TGSL and I'll check on the new coil and pcb IGSL TGSL.

I'll make a tutorial for the construction and calibration of the phase meter and I'll post here

thank you
zoomix

Instabillity is mostly related to coil shielding and proper shield connection to the rest of circuitry (cable, connectors, pcb, proper wire on proper place etc...)
Have you filled your coils with epoxy resin?
Have you fixed them good?
Even slightest relative movement will cause horrible changes in behavior, in case you haven't fixed your coil properly.