IDX-PRO+VDI

[hoadlies]

@ barry the problem with the carbon is getting a reliable connection, i have some woven carbon cloth(i actually sit my irons on it) it tests ok resistance wise, i had an idea about using it as a shield but i could not get a reliable connection to it so gave up, every thing i tried gave a "noisy" contact.
thats not to say its no good, just that we need a reliable connection method.

HI s/user,, IT was just a thought I guess one could fit a drain wire whilst laying up the carbon-fibre in the epoxy-mix ???..

TAKE it easy-mate,,,,,,,,BARRY..

[hoadlies]

I have a couple of centertapped RX coils ready to test with my "Super TGSL With H Bridge TX Diff RX Quad Sampling" MD.
I hit a snag with the Disc and Geb but that's almost worked out now. The beauty of the center tapped coil is no need for
shielding. That makes it easier to make and also a bit more sensitive both good things in my book. You have to go with
a differential input but that allows quad sampling which gets rid of some voltage jitter and on and on. Thus creating a
much improved detector. The proof is in the pudding though and one wonders why the big guys aren't making detectors
with center tapped coils...

HI S/D,, OK is was following your Super TGSL thread untill you run into problems ,I will keep my Eye on your progress Mate ,I guess the BIG boys want to do coils as cheaply as Possible ???

I am to visit ''COIL-TECH'' as the are in Sth AUST who make replacement coils [mainly for ''Mine-Lab'' units] I will ask him about this type of coil ..
Next time I visit Adelaide I will go see them ..

HOW's the PI Coil getting along [looks good!!] .
I guess your weather is improving as is Ours here So you may get on the Ground Soon..[Look for tins of Gold-COINS ,take your dog for a walk HA,Haar..

GOODONYA MATE THANK for the reply,,,,,,,,,,,,,BARRY..

[Waikiki_Sweep]

NO SHELLS COILS FIBERGLASS OVER GRAPHITE SHIEL

Why to use coil shells at all? Without shells coil weights much less and you can build a really big coil.

Technology is relatively easy:

Wind coils.
Cover with insulation, for example paper tape.
Wind a spiral using thin silverplated stranded wires to connect a shield later.
Paint with graphite + epoxy 1:1 by weght, live 5 mm gap.
Wind by fiberglass
Put coil between plastic bags (epoxy not sticks to it) put in on something soft like towel
Pour epoxy (marine epoxy, no polyester please)
Cover with towel then put desk on top, than apply pressure several kg.
After hardening remove plastic bags and sandpaper results.

On picture you can see most of coils 17-18" long.



For DD/SEF/"8" coils left a wire loop to balance it when epoxy gets hard. Loop has to be connected to the grounded end of coil so it has no needs for shielding.

[sinclairuser]

@ barry the problem with the carbon is getting a reliable connection, i have some woven carbon cloth(i actually sit my irons on it) it tests ok resistance wise, i had an idea about using it as a shield but i could not get a reliable connection to it so gave up, every thing i tried gave a "noisy" contact.
thats not to say its no good, just that we need a reliable connection method.

[Silver Dollar]

I have a couple of centertapped RX coils ready to test with my "Super TGSL With H Bridge TX Diff RX Quad Sampling" MD.
I hit a snag with the Disc and Geb but that's almost worked out now. The beauty of the center tapped coil is no need for
shielding. That makes it easier to make and also a bit more sensitive both good things in my book. You have to go with
a differential input but that allows quad sampling which gets rid of some voltage jitter and on and on. Thus creating a
much improved detector. The proof is in the pudding though and one wonders why the big guys aren't making detectors
with center tapped coils...

[mohandes]

hi
this is not deeper but max depth 1.5to 2meter .
سلام
مدارش برد زیادی نداره نهایتا اقایی کنه 2متر ( بعیده
ولی جالبه من دارم تغییرات اخرش رو بهش اضاف میکنم

[hoadlies]

carbon fibre shells plus 2 tone question..

HI ,,ALL ,,Well i have built another lighter & better DD coil for my IDX project ,my shells are from fibre-glass [home-made]..
I was wondering if carbon-fibre would be stronger & lighter ,Plus the corbon could also be the shield ???''ANY-ONE-TRIED-THIS''??????
MY coil was wound with actual .2mm wire RX & TX with.71 mm wire & it came out much better than my 1st attempt .I made it a 10''X9'' oval .
THE geb pot is now OK at 11-12-oclock by increasing the RX cap a little.. not tried a buried coin as yet but it seems more sensitive than my 1st ..
Question 1,,,,,,,, please i bought when i ordered my kit from silver-Dog,,,I ordered 2x 2 tone boards that he has on his site for TGSL Has anyone used this board for the IDX ,as I noticed a different board used ,but not on s/dogs site??????
Can it be used ????..

question2,,,,, Has anyone tried the Centre-tapped coil idea's that DAVOR &MIKELB has written about ,are they worth investigating ..MIKES messages are great but Above my grade..HA.Haar..

I have nearly finished an 8'' Coplaner coil similar to Dons instructions I will post some pics later ..

STEVE my Graphite -cellulose mixture is great & it adheres to my Fibre-glass shells just fine ,maybe a little strong @ 600ohms from edge to edge on my 8'' shells ..I found it better to use a wad of cloth to spread it thinnly over that area ..rather than a paint brush !!!!
My DD coils were taped with Micropore -medical tape & the mixture painted on & it gets absorbed well into the thin tape .. GREAT after so many brew's I made & used & wasted much Graphite powder ,But I grind that from very large 1/2 worn-Wind turbine Brushes ..which I get for free about 4 brushes yield a jam-jar-full ..

The detector is Great ''Thanks'' to all the help from Here CHEERS FROM OZ,,,,,,,,,,BARRY..

[Qiaozhi]

سلام مهندس این مدار تا چند مترمیتونه بزنه

Please read the forum rules -> Basic Rules of the Forums
and make your posts in English.

[peman]

سلام مهندس این مدار تا چند مترمیتونه بزنه

[Koala]

Its not enough to have a sheet above or below. The screen needs to be a tube, / wrap forming a tube - if it was graphite the tube sheol can be continuous. If it is a proper conductor like all etc it needs a break in it - so currents dont race around the sheild.

Cheers thought I could get away with just a sheet for testing

[golfnut]

Its not enough to have a sheet above or below. The screen needs to be a tube, / wrap forming a tube - if it was graphite the tube sheol can be continuous. If it is a proper conductor like all etc it needs a break in it - so currents dont race around the sheild.

[Koala]

the screen may give a little local emi reduction - not sure.

good luck

getting somewhere not sure where


If I blow above the coil not at the coil it's enough to set the detector chattering. So thought it had to be a shield problem. Attached a large square of space blanket to ground checked the blanket is conductive checked the ground connection went all the way to the board and connector all fine makes no difference.

[ossamaussama]

Assembled this unit. Showed excellent results. Coil 13 "range on the copper coin 45mm diameter is 60cm. Works steadily. At ground on this coin depth 40cm. https://www.youtube.com/watch?v=xXyIXFg2pKE

what is the sound in video ?

what is secrete for this powerful detection range

[golfnut]

the screen may give a little local emi reduction - not sure.

good luck

[Koala]

Just compared my wave form against an original 8" CC.

Mine is a pure sine wave but is jumping all over the place

the original has regular spikes along the sine wave but is rock steady.

Makes sense to why the original is stable but mine isn't

Need to find out how to make mine steady is it because I have no shield yet thought it would make no difference when the coil is not moved and nothing near it.