Question about tgsl

[waltr]

Shielding is Electrostatic. One thing that can happen without is it will False when the coil changes distance from fround or when brushed across grass.
Dry conditions tend to be worse on producing electrostatic fields. Why static electric shocks are worse in winter than summer here (winters are drier).

when I wrap a tape around the coils I don't reach a good nulling

Did wrapping with tape change the Inductance?

[waleed]

I'm curious to ask sth, what if I didn't shield my coil,what would happen?, I got a good results without shielding but when I wrap a tape around the coils I don't reach a good nulling, most of my search will be on a drying ground and far away from buildings. I just want to know what is the main purpose of the shielding.

[waleed]

Really thank you waltr for your contribution from the beginning,and thanks to this forum, I was able to success with your help,now if I want to make this device agsin I know how to avoid mistakes that I have faced before,all are clear include the device operation.

[waltr]

I never tried the two tone on the TGSL.
Instead I build the IDX-VDI with a graphic display.

https://www.geotech1.com/forums/showthread.php?18051-IDX-PRO-VDI

Sounds like you have your TGSL operating pretty well.
Now you need to go out and use it to start learning what the sounds are telling you.
Even though this is a Beep and Dig detector how it beeps have subtle hints to what the target can be.

[waleed]

Who tried two tone ID?, does it give different sound on iron only or iron and foil??

Oki I'm still waiting an answer.

Anyway, waltr I'm happy with my device now,I made the coils exactly the same way as dbowers, the deepest null I have reached was about 0.4v, disc works good and depth is enough for me ,last thing that I'll make is the covers..

[waleed]

Who tried two tones ID?, does it give different sound on iron only or iron and foil??

[6666]

Yes I have been doing test patches seems to work ok

[waltr]

Have you done test patches to measure resistance?

[6666]

Yes. It is what I had.
I used MINWAX Fast-Drying Polyurethane, Clear Satin

Thanks, will give it a try, been using oil based wood lacquer.

[waltr]

Is the polyurethane oil based ?

Yes. It is what I had.
I used MINWAX Fast-Drying Polyurethane, Clear Satin

[6666]

I mix graphite power with polyurethane (a finish for wood) in a ratio of 1 part graphite to 2 parts polyurethane by volume.

I mix a small batch and paint on a piece of cardboard to test conductivity. When dry getting resistance of 200-700 Ohms on DVM leads about 1 cm apart. I tested many paints and glues to mix with the graphite and found polyurethane worked the most consistent

On the TGSL coils I first wrap with electrical tape. then wrap a spiral of thin bare wire at about 2cm spacing. Used wire wrap wire with the insulation removed. This is tinned 34 ga. Be sure to leave enough extra to connect to the cable ground.

Then paint on the graphite/polyurethane mixture. Last is another layer of electrical tape.
This is close to what the Russian guy's TGSL video shows.

Test patches and sample wire.
[ATTACH]49667[/ATTACH]

Is the polyurethane oil based ?

[kt315]

guys we mean HIGH VOLTAGE if we say about electrostatic field protection. 1...2...5...10 KILOvolts. 1000... 2000... 5000... 10 000V.
you CAN NOT measure resistance of ESFP layer by your ORDINARY Ohm meter. you have to use MEGA-OHMMETER megohmmeter. yes, i know this class
of instruments is sure unknown for you, but try learn electronics.
ok, you know now that MEGAOHMETER measures a resistance given HIGH voltage (on probes)
because there is a HV CONVERTER 'STEP UP' inside it. read in your language https://en.wikipedia.org/wiki/Megohmmeter

https://www.aliexpress.com/item/4000478004584.html?spm=a2g0o.productlist.0.0.554d418b4QVoDl&algo_pvid=f9e6c9f7-7b43-434c-b4e4-d8e407cf0a4c&algo_expid=f9e6c9f7-7b43-434c-b4e4-d8e407cf0a4c-7&btsid=0ab6f82c15841454004285447e6c9c&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_

BM500A 1000V Digital Auto Range Insulation Resistance Meter Tester Megohmmeter Voltmeter Megger High Voltage LED indication

Features:
1. An accurate,reliable and easy to measure insulation resistance,voltage.
2. Wide measuring range,voltage:250V/500V/1000V, resistance:0.001～1999MΩ.
3. Large LCD display,convenient to read data,max display counts 1999.
4. Stable performance,LED light indicator,data hold and auto range.
5. Wide range of applications:Such as transformer,motor,cable,switch and electric appliances.

Description:
1. BM500A is a digital insulation resistance tester,output test voltage can be switched among 250V/500V/1000V.
2. More advantages,such as stable performance,high accuracy,auto range and data hold.
3. A ideal tool for electric equipment maintenance,testing and inspection.

Specifications:
Model: BM500A Color: Gray&Red
Display Count: 1999 Auto range: Yes
Data hold: Yes High Voltage Indication: Yes
Low battery Indication: Yes Rated voltage: 250V/500V/1000V
Measurement range:0.001-1999MΩ Minimun resolution: 0.001MΩ
Accuracy: ?(5%RDG+5) 250V: about 500kΩ
500V: about 1.5MΩ 1000V: about 5MΩ
Product Size: 138 x 69 x 39mm Product Net Weight: 207g
Short circuit current: Not less than 1.5mA
Power: 9V 6F22 battery (Not included)
Open circuit voltage: 90%-110% of the rated voltage
Insulation Resistance(Ω): Test Voltage: 100V/250V/500V/1000V

[waltr]

I mix graphite power with polyurethane (a finish for wood) in a ratio of 1 part graphite to 2 parts polyurethane by volume.

I mix a small batch and paint on a piece of cardboard to test conductivity. When dry getting resistance of 200-700 Ohms on DVM leads about 1 cm apart. I tested many paints and glues to mix with the graphite and found polyurethane worked the most consistent

On the TGSL coils I first wrap with electrical tape. then wrap a spiral of thin bare wire at about 2cm spacing. Used wire wrap wire with the insulation removed. This is tinned 34 ga. Be sure to leave enough extra to connect to the cable ground.

Then paint on the graphite/polyurethane mixture. Last is another layer of electrical tape.
This is close to what the Russian guy's TGSL video shows.

Test patches and sample wire.

[waleed]

GREAT news.
I feel you really need to use a Scope to check what the RX to TX phase is when Nulling.
A DVM can be used and the TGSL will work quite well. For now finish and use the TGSL. That is what I did with the first coil I built and it worked well in the field.
My second coil was near perfect but in field performance was not a lot better.

What size piece of foil did you try? I use two pieces, one less than 1x1cm which should reject with Disc control at abut 1/4 turn.
Then one no larger than 2x2cm which should reject at almost 1/2 turn.
Larger pieces of foil will not reject.

The piece of foil I used was about 5x10cm, oki I'll try as you said, but I want to ask how exactly you shielded your coil?, did you mix the graphite powder with epoxy and put it directly on the coil?, or you wrapped an electrical tape on the coil and then you wrapped a naked wire around the tape after that you installed the mixed powder,right?

[waltr]

Waltr, finally the device is working again,I changed some components to solve the problem, and I tested everything all seems good, I made the coils exactly as dbowers document (same template and turns) and the same way you did, then I connected the coil but the deepest null I reached was 0.20v I did it on multimeter not on oscilloscope, then I was able to reject ferrite then iron but I couldn't reject foil, maybe the difference frequency between TX and RX is not correct? Or the phase shift?, what would make foil not rejected?

GREAT news.
I feel you really need to use a Scope to check what the RX to TX phase is when Nulling.
A DVM can be used and the TGSL will work quite well. For now finish and use the TGSL. That is what I did with the first coil I built and it worked well in the field.
My second coil was near perfect but in field performance was not a lot better.

What size piece of foil did you try? I use two pieces, one less than 1x1cm which should reject with Disc control at abut 1/4 turn.
Then one no larger than 2x2cm which should reject at almost 1/2 turn.
Larger pieces of foil will not reject.