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Hi all,,,Even though I have collected a ton of information from the Forum over the 2+years I've been a member I'm still at a loss with the correct method of wiring and shielding the coils of the IDX, the TGSL and the IGSL DIY Detectors. I really would be grateful and appreciative if any members would have any wiring diagrams of these three detectors that they could possibly post. I've spent all winter trying to learn how to use the DSO 5102P Oscope and how to tune VLF 'DD' Coils and Concentrics but I still don't think I've wired them correctly. I really would appreciate any help with this. Thanks in advance. Regards,,,Marty
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Hi Marty, what instrumentation do you have in your possession? -
Have you seen Don's article:Originally posted by MartyJ1963 View Post
https://docs.google.com/viewer?a=v&p...N2Q3MmVjNDlmOA
Its on his web site:
https://sites.google.com/site/dbcoil...resources/tgslComment
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With DD coils, the trick is to first get the TX coil oscillating at correct frequency(according to which project you are building)
Then null the RX coil directly(without any capacitor attached), by looking for minimum output amplitude on scope. This is the balanced state between TX and RX. Finally, tune the RX coil according to recommended RX resonant freq. by adding capacitor/ and smaller picofarads capacitor for fine tuning. Thats all. For final precise tuning, gently move RX while observing scope. Remember the TX goes on the right side and is fixed into place, followed by the RX coil on the left side which overlaps on top of the TX coil. If your getting double beeps, just change around wires of RX. End .
With concentric coils, its a little bit more difficult because of the bucking coil, which is used to cancel out the TX coil and null the RX. So the process can be a little convoluted.
One thing Iv'e noticed is that once the RX coil is tuned to correct resonant frequency, and the TX coil is at correct oscillating freq., when both are balanced, the correct phase lead/lag falls into place nicely with just very tiny movement/shifting of the RX coil. also with DD, secure the entire TX coil in place(hot glue), but with RX, only secure the circular side, leaving a part of it for manipulation for final tuning(nulling)
Always use the shape below for DD, it is easier to balance and is much better overall.Comment
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First of all, a really big thanks to everyone for their individual help,,,I really respect the knowledge that is shared here on Geotech and I have the utmost gratitude and respect also for all the 'Geotechers' that are willing to go out of their way and share their circuits/knowledge/views and their precious time to help the needs of others,,,really big thanks! @Dbanner,,,Thanks for the great explanation you wrote in post#6,,,it is the easiest explanation I've found so far (For me anyway) and I can't wait to try it the way you've descibed. For the last 2 months I have been planning/drawing/estimating a new Vacuum form that I will hopefully building soon. The reason I've spent a lot of time working out first is that when I start to actually build it I want to photograph the build process in case anyone else might fancy building it for themselves. I'll be making a detailed PDF on the build process and will start a new thread on this subject once I begin building. I already have a Vacuum form that works pretty goodbut the biggest Coil shells I can manage are only 8.5" (Inches). The new one I will be building will have a 'Heat element' canopy at the top with the Vacuum table beneath it. The vacuum table 'Deck' will be interchangeable so it is able to form small to large coil shells as well as detector enclosures/fittings etc,,,,Like I said, once I've learnt a little more about coil nulling and be able to do it consistently with repeatable results then I'll start making the new Former so I can then fully complete my coils etc,,,The only other thing I'm looking for that I don't have much information on is a list of the frequencies for both the TX and RX coils of the IDX/TGSL/IGSL. I know that some of these VLF detectors can be tuned to different frequencies but I don't have much information on what these frequencies are or which detectors can handle different frequencies or their capacitances for the frequencies,,,,,,,,Thanks again everyone for your help,,much appreciated,,,Regards,,MartyComment
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@DGM,,,,,I have 2 different inductance meters,,,but when I take readings with them, if one says 300uh the other says 360uh-ish,,so out of those I never know which one to trust,,Lol,,and I have a Hantek DSO 5102P 100MHZ Oscope. I have yet to learn it,,even though I have the manual and stacks of Video (Tuitional) I am still struggling. I'm after just simple, basic instructions to get me started in coil nulling so I can progress and learn more from there. I have had no trouble with Mono coils. I can build them pretty quickly and accurately and have several different sizes now for each of my PI Detectors. I've been trying all winter to learn the oscope but as I say, I'm really struggling with it. I can build the DD template and coil forms accurately and build DD coils successfully. I test the frequency by connecting to the coil generator I built from the layout posted by KT315,,,I either 'Add' or 'Deduct' turns of wire from the coil (while it's connected to the generator) to get the correct frequency. I'm confused with how to measure the phase of the TX and RX also. It'll be great if someone can give me some guidance with this. Regards,,,MartyComment
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Hello Guru’s.
I have a question for all the coil makers. I am making a Concentric coil for a Minelab P.I. GPX detector.
My dilemma is, when winding the Bucking Coil, do I join it up to the TX coil, as in some diagrams I have seen on the forum? Or can it be left as unconnected winding's around the RX coil?
Does the field from the TX coil, create an inductive reverse field in an unconnected bucking coil winding?
Thanks, in anticipation, Carl, BB Sailor, Eric foster, or other gurus. Regards from ozgold.Comment
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bucking coil doing around RX coil and connected IN-SERIALLY ANTI-PHASELY to TX coilComment
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