TESORO GOLDEN SABRE

[habitbraker]

Hello!
I made new coil and got one interesting thing: is this normal that I can reject ferrite on all GEB trimmer settings? Ok, silver is not detectable on all settings...

[ApBerg]

Yes, this is almost normal, look at the start.. post no. 15... long ago....
At some point ferrit give,s an echo sound ?! . Look for the point that is silence for ferrite and give's good sens. for large silver !
As I remember the 15 pF cap is te one to look at if the adjustment is not o.k.
Best regards.

Ap

Hello!
I made new coil and got one interesting thing: is this normal that I can reject ferrite on all GEB trimmer settings? Ok, silver is not detectable on all settings...

[dfbowers]

Hello!
I made new coil and got one interesting thing: is this normal that I can reject ferrite on all GEB trimmer settings? Ok, silver is not detectable on all settings...

I don't think so. Here is the way that mine works:

With the GB pot in the full CCW position AND in the all metal mode, ferrite will respond with positive signal. Advancing the GB pot CW, there should be a point where ferrite goes quiet, somewhere around the mid range setting. Advancing maybe another 10 to 15 degrees, ferrite will again be detect, but you will now get a negative response, meaning that you will get a signal from ferrite at some time after it has passed the coil.

Also, switching to the DISC mode, silver will no longer respond if you advance the GB pot too far past the point where ferrite is rejected.

If this is not the case, then maybe your phasing is off.
Don

Do you have a way to check your null phase?
http://174.132.129.189/~moreland/for...=16122&page=21

[habitbraker]

I don't think so. Here is the way that mine works:

With the GB pot in the full CCW position AND in the all metal mode, ferrite will respond with positive signal. Advancing the GB pot CW, there should be a point where ferrite goes quiet, somewhere around the mid range setting. Advancing maybe another 10 to 15 degrees, ferrite will again be detect, but you will now get a negative response, meaning that you will get a signal from ferrite at some time after it has passed the coil.

Also, switching to the DISC mode, silver will no longer respond if you advance the GB pot too far past the point where ferrite is rejected.

If this is not the case, then maybe your phasing is off.
Don

Do you have a way to check your null phase?
http://174.132.129.189/~moreland/forums/showthread.php?t=16122&page=21

thanks! It is exactly like you described with my first coil - a small area of GB pot (about at middle), where ferrite is rejected, but silver is accepted only on on eside of that turning area. That I understand.
But this second coil...
In spite of that sensivity is great as well as disc.

I potted it anyway to check how it works on field.
My null phase is different - about -40deg (lagging TX)
On this second coil I didnt ground RX and didnt connect hichiker wire. (I red your exp with wet grass)

In few days I will report how it works

[Qiaozhi]

My null phase is different - about -40deg (lagging TX)
On this second coil I didnt ground RX and didnt connect hichiker wire. (I red your exp with wet grass)

In few days I will report how it works

This is possibly he reason why the null phase is different.

[simonbaker]

I probably have 30+ hours of field use on Ivconic's version with fantastic results. I only have a few hours on this version and my only concern is stability. I actually replaced the 1M Ohm resistors with the original 470K Ohm resistors used on earlier versions, just because I can't keep it quiet on occasion. Doubling the gain on this stage is a two edged sword. I'm not saying that someone else may not have good results with this version and replacing the 1M Ohm resistors is easy. I think that I may have better results far away from electrical noise.

Also, question for Eduardo: Is the 100uF cap circled below a substitute for all the 100nF decoupling caps on Ivconic's version? (Note.. Decoupling caps are not pictured on any of the schematics but are evident on Ivconic's TGSL PCB version). There is a reason for using 100nF decoupling caps, especially for the LM308s. Typically, smaller ceramics do a better job of filtering noise over the electrolytics, at least that is what I have read. I'm just looking for justification on leaving off the 100nF caps.

As far as the audio section, this is the way to go to drive an speaker!

Silverdog, I'm working on documentation at the moment. I need to get more than just a "read only" version of Adobe!!

I'm lost in the weeds -- is there a Sprint PCB layout file for the latest eduardo version (fixed audio capacitor ground, replace 100uF bypasses with 100nF) somewhere we can download? And was a complete schematic ever posted?

Regards,

-SB

[habitbraker]

On this page I think: http://www.geotech1.com/forums/showt...12692&page=176

[habitbraker]

I know its completly useless, but I connected my new TX coil, just to check frequency and noticed that I can detect metal objects anyway Coins at about 3cm, 10x5cm copper plate - 10cm, large iron even deeper. Something like BFO?.

I Guess that frequency changes really affect TGSL

[simonbaker]

The last modification TGSL.Air test:gold ring 40cm in the air,and is very stable.Regards.

Hi eduardo1979:

Is this zip of your layout file password protected?

Somehow I missed the memo.

-SB

[eduardo1979]

Tgsl Edu

Tgsl complet.

[simonbaker]

Tgsl complet.

Thanks eduardo.

(For some reason, the Window "unzipper" thinks the .lay file is password protected, but another unzipper worked fine.)

If anyone has complete schematic including changes, would be nice to have.

Regards,

-SB

[fmnotes]

Hello.
I request a question.
I have made tgsl 3.0 version.
detects 1 Euro in the 16 cm
it is well?
if exists problem,
say me what I correct.
I thank.

[Dennis the Mennis]

Hi Dtm:

I forgot you made TGS, not TGSL -- is that correct? Or do you have both?

For TGS, that changes my understanding of some of your issues. For example, it probably is a little more important to have the 100K DISC pot instead of 10K, because there is another 10K pot in parallel. Also, C9 probably not a problem because TX wave will be smooth and smaller voltage. Also, you would expect less air depth because smaller TX signal.

Next step is to get results of your DISC mode detection - what depth, what coins used? Also, which circuit (TGS or TGSL)?!

TGSL for dummies project is ambitious, and you end up teaching yourself how it all works! Some people may want permissions for exact design for example PCB layouts I would think. I hope someday I can make a significantly modified design and my own layout of some MD and publish a book/manual also. I use lulu.com for my publishing projects.

Cheers,

-SB

Hi ,

I made , or trying to make ... , the TGS .

I really don't know what to expect for DISC .

It seems to discriminate iron in all setting of the disc pot .

What can I use more for disc testing ?
A smallish piece of AL foil , US nickel ( seems similar as the inside of a 2euro coin ( have to dismantle a 2 euro coin ) ??
Any suggestions for the test and a what distances should it disc out ?

kind regards ,

Dennis the Mennis

[habitbraker]

I also disc out iron in all disc pot settings.At min it makes cracks and chatters
I usually test with foil from this:http://www.balcan.net/files/images/orbit.jpg
I can disc out it at half of disc pot setting

When it is discriminated i get 30-35cm for my coins. I will try to find euro coin soon...

On equestion for you Dennis: How noch function is working? Can you disc pultabs and at same time detect Cu+Nickel alloy coins?

[satdaveuk]

pcb board

Can anyone here tell me how i can flip the board on the pdf format? because i dont know how to do it.
Or can someone post me a ordenary picture I can put onto office, because then its so easy.

Many thanks in advance

Dave