IDX-PRO+VDI

[Waikiki_Sweep]

> Question do you wind a shield wire around the coils say 1'' apart ??? or do you use a single trand on the coil edge ????

I like to make spiral winding over coil bundle with step 0.5-1 inch. I am using 19 stands AWG 24 silverplated wire but spliting it in two bunches of 9 thin strands and wind them over left and right sides of coil.
So you will have reliable contact between graphite shield and grounding wire everywhere. Remember to make a gap! Also if you wave a piece of such 19 stands AWG 24 wire near coil of any VLF or PI detector you will see
that this is not a target and detectors can't detect it so this wire has no influence on your coil setup. Solid wire, aluminum or cooper foil are acting like target so do not use it in your coils.

[hoadlies]

hi ,, ALL ,Just a few pics of the 2x new coils I made ..


LEARNING a bit as I go <BUT cannot achieve the air tests that most do on here ,,GEB-OK can do that OK now, it seems once you get to reject the ferrite ,& try as I might I cannot improve the air test A 20 cent size coin AT 30cm ..

CHEERS ALL ,,,,,,,,,BARRY..

[Koala]

have you got the sens pot turned fully the right way

with a good null pin 6 U1 less than 200mv you then have to adjust the rx caps for good depth and good phase you can go too far with depth on a air test and the coil will became unstable in the ground

My coils 27cm DD if I go to 40+cm airtest then the coil is no good on the ground too much chatter 40 seems the limit with my builds. That's on a UK copper 2p (25.9 mm diameter and 1.85mm thick)

[hoadlies]

> Question do you wind a shield wire around the coils say 1'' apart ??? or do you use a single trand on the coil edge ????

I like to make spiral winding over coil bundle with step 0.5-1 inch. I am using 19 stands AWG 24 silverplated wire but spliting it in two bunches of 9 thin strands and wind them over left and right sides of coil.
So you will have reliable contact between graphite shield and grounding wire everywhere. Remember to make a gap! Also if you wave a piece of such 19 stands AWG 24 wire near coil of any VLF or PI detector you will see
that this is not a target and detectors can't detect it so this wire has no influence on your coil setup. Solid wire, aluminum or cooper foil are acting like target so do not use it in your coils.

THANKYOU ,,WAIKIKI ,, that very good information ,as I on my DD coils used a solid copper wire on the edge of the coils [single strand] & yes leaving a gap ..
So next coil I will use your method ..

GREAT,, MATE ,,,,,,,,,,BARRY..

[hoadlies]

have you got the sens pot turned fully the right way

with a good null pin 6 U1 less than 200mv you then have to adjust the rx caps for good depth and good phase you can go too far with depth on a air test and the coil will became unstable in the ground

My coils 27cm DD if I go to 40+cm airtest then the coil is no good on the ground too much chatter 40 seems the limit with my builds. That's on a UK copper 2p (25.9 mm diameter and 1.85mm thick)

THANKS,,, KOALA,,,,for reply ,, null less than 200mv using ac on a good multimeter ????? or on a scope .. ,On the scope trace would I aim for lowest signal for Null ???? [lowest amplitude???] ..I have not tied that !!!.. but can ..

THIS is what I have been doing that is get TX Frequency as close to 6.59 kz with cap selection ,,Then null at minimum on pin 6 preamp .. Then adjust GEB with the RX caps to reject ferrite rod 3/8'' [10mm ,2'' long][usually 22nf+10nf or close to that ]..

MY sensitivity is nervous at full turn [no matter what cap values are used on rx .on a scale 1-10 say on the sens pot no noise at 8 but on say 9 to 10 a low noise .. I have all leads from boards to pots as short & twisted as possible [Do you feel I should use shielded cable instead of wire ]??????.. to allow full use of sens pot ????..
Copper seems to pick-up the futher-est in air test on mine at least ..thin shim 1'' wide folded 3 times in a square picks up better than a 50cent coin OZ coin..

I am still most happy with the unit ,I need to do more ground tests !!!

I feel the DD coils that I built are more sensitive than this new Coplaner 8'' type ..but untill I test on buried coins I will not know ..

I may build a little bit larger DD shape [maybe 11''Xsay 9''????..

ALL GOOD FUN for the Old Grey-Matter HA,Haar..

CHEERS KOALA,,,,,,,,,,,,,BARRY IN ''OZ'' nice weather here today 30c ..

[Koala]

THANKS,,, KOALA,,,,for reply ,, null less than 200mv using ac on a good multimeter ????? or on a scope .. ,On the scope trace would I aim for lowest signal for Null ???? [lowest amplitude???] ..I have not tied that !!!.. but can ..

THIS is what I have been doing that is get TX Frequency as close to 6.59 kz with cap selection ,,Then null at minimum on pin 6 preamp .. Then adjust GEB with the RX caps to reject ferrite rod 3/8'' [10mm ,2'' long][usually 22nf+10nf or close to that ]..

MY sensitivity is nervous at full turn [no matter what cap values are used on rx .on a scale 1-10 say on the sens pot no noise at 8 but on say 9 to 10 a low noise .. I have all leads from boards to pots as short & twisted as possible [Do you feel I should use shielded cable instead of wire ]??????.. to allow full use of sens pot ????..
Copper seems to pick-up the futher-est in air test on mine at least ..thin shim 1'' wide folded 3 times in a square picks up better than a 50cent coin OZ coin..

I am still most happy with the unit ,I need to do more ground tests !!!

I feel the DD coils that I built are more sensitive than this new Coplaner 8'' type ..but untill I test on buried coins I will not know ..

I may build a little bit larger DD shape [maybe 11''Xsay 9''????..

ALL GOOD FUN for the Old Grey-Matter HA,Haar..

CHEERS KOALA,,,,,,,,,,,,,BARRY IN ''OZ'' nice weather here today 30c ..

less than 200mv pp on a scope. AC on my fluke multimeter does not work correctly.


"MY sensitivity is nervous at full turn [no matter what cap values are" Just had that problem myself. Just cleaned out my mixing pot. Turns out the epoxy I am using can hold quite a charge of electricity. The flakes of epoxy were sticking to me with the static charge. Will be fine with a proper shield.

[Koala]

Would like to try some self bonded wire I linked to earlier. Anyone know of a supplier to the public the type that uses a alcohol solvent. Found some email for quote businesses and seen a video of it being used but can't find a supplier

[golfnut]

"seems once you get to reject the ferrite ,& try as I might I cannot improve the air test A 20 cent size coin AT 30cm .."

You dont want more - what you have sounds perfect.


if you go for a 40" air test, it wont work over ground as the Rx and Tx will be so close. It will false all the time/

try what you have and it will be fine S

[golfnut]

Dont forget Barry the null is secondary importance. The correct phasing makes or breaks your coil.

If phase correct by tweaking position of coils, and maybe the Rx cap up or down 1 or 2 nF --- when rejectin ferrite, and irn and accepting all other phases - then take a look at the null.


If 300mY or less leave well alone. Your away.

[seadoggy]

hello guys!Do i need set up something here before i program PIC 16f88??pls help

[hoadlies]

Dont forget Barry the null is secondary importance. The correct phasing makes or breaks your coil.

If phase correct by tweaking position of coils, and maybe the Rx cap up or down 1 or 2 nF --- when rejectin ferrite, and irn and accepting all other phases - then take a look at the null.


If 300mY or less leave well alone. Your away.

HI STEVE GREAT ADVICE AS PER USUAL , ALL of my 3 coils built are approx same air test within a coulpe cm or so ,& i tried each time to improve but I must have found the limit of my IDX ,,

What I have improved with these last 2x coils is the GEB -reject ferrite at 11-12oclock & thats good ..

NOW also have a great formula for the graphite shield mix [very pleased to have found that ] of course from much help from this site& members ,,

STEVE ,MY son is interested so we will build another soon & I will buy a bare board to experiment with following your higher frquency mods etc..

Soon to get out to test on actual ground to test the DD vs the coplaner will be interesting..

I am to obtain some fibre-glass woven -cloth in an attempt to make lighter shells & may try as suggested by Waikiki to not use a shell at all ??? but for that I need the woven type cloth for wrapping etc etc ..

I may lookinto some audio mods to raise frequency etc for my old ears HAhaar ,I have done many audio fet projects before ,so into the Junk-box ,,..

The IDX is a great project & I am glad that you STEVE changed my mind from the TGSL ,, THANKS-MATE ,,,,,BARRY..

[sinclairuser]

has anyone else noticed the skype tracker i this thread?, dont normally get any trackers here,just seems to be the idx thread.

[Waikiki_Sweep]

has anyone else noticed the skype tracker i this thread?, dont normally get any trackers here,just seems to be the idx thread.

Everything looks clean from my computer. Can you give more details, screenshots?

[sinclairuser]

not on this machine waikiki, ghostery detects one tracker on this page "skype"
only other thing i can find out is its some sort of widget

�PNG IHDR(-SsBIT��O�6PLTE������������������������������������ ��ĺ��������������0�"tRNS@��f pHYs � �B�4�tEXtCreation Time8/18/05�>��%tEXtSoftwareMacromedia Fireworks MX 2004�v��zIDATW]�A� @QPZ+�(��lAI���B"���g���,�VR�˚�-Q�3yg�.Z˕01'��7I�e�-�[F�9��S�@sFrY�t�aH�2�Q��Dd��{'�U���.2��D?p���\�IEND �B`�

[Waikiki_Sweep]

Thank you. Now I see. That strange code has been inserted into "META keywords" section on every page in this IDX-PRO+VDI thread. No codes are allowed in "keywords" tag by the book.
Sure it is mistake but may be it is malicious attempt too.
As I can see vBulletin generating set of keywords automatically for every page and for this thread it has inserted that code for no reason.
Probably something was wrong at the moment of creation of the IDX-PRO+VDI thread or once layout of forum has been changed.
If you have old pages saved on your computer you can check
HTML source <meta name="keywords" content="???? strange code are here ?????">
I Will dig more in it when have a time.