TESORO GOLDEN SABRE

[turtlebowl]

EDU.SCH viewer/ Program ??

Hey guys. I have several times downloaded giftpaks etc and been unable to open them.
I want to make Eduardo's PCB but need the program to open his files. I currently use the Sprint 5 software.
Can someone dirrect me to a program that opens .SCH files??

Also while I am asking Questions........... is the TSGL a D-120 disc range?? D-90??
Are any versions D-180?? What range is Eduardos TSGL.EDU ????
Thank you gentlemen, TB

[simonbaker]

Hey guys. I have several times downloaded giftpaks etc and been unable to open them.
I want to make Eduardo's PCB but need the program to open his files. I currently use the Sprint 5 software.
Can someone dirrect me to a program that opens .SCH files??

Also while I am asking Questions........... is the TSGL a D-120 disc range?? D-90??
Are any versions D-180?? What range is Eduardos TSGL.EDU ????
Thank you gentlemen, TB

Use ExpressSCH to open/modify .SCH files. Find it here: http://www.expresspcb.com/ExpressPCBHtm/Download.htm . However, that is just a schematic, not PCB layout.

TGSL is basically a 90 deg DISC range, but I think the actual range of metals depends on the TX frequency as well as the phase-shift range. TGSL in DISC mode can detect all metals beyond iron I think.

No greater range disc modes available yet that I know of. I designed a circuit for 180 DISC but it is not centered correctly yet -- would require more parts or complete different phase setup with coils (or design change).

Eduardos TGSL will have same discrim range as all the others.

Regards,

-SB

[dfbowers]

as previously stated, I built TGS, which worked ,but I had trouble with notch filter. I was going to build TGSL, but I settled on TGSL edu, I now get 30 cm depth. I went out hunting a 100 year old high school playfield and found a canadian quarter and some pennies. To my amazement, I found razor sharp discrimination between silver and aluminum. complete discrimination of large steel, but strangely I was hitting old magnetic sensitive beer bottlecaps. Here are some pics of my latest vacuum formed coils. If it is helpful to anyone, I found that you need to get the abs hot enough that its sagging almost to the bottom of the oven, carefully watch it! then you place the frame on the vacuum box, and you will here the rPMs of the shopvac go up, and you will get good detail on your coil shell. On nulling the coil, I hold the top coil while watching the oscilloscope, then drop dollar store glue gun glue on coil points, I then use dollar store $1. epoxy to secure coils further. Then use 24 hr epoxy to fill the coilshell with no movement.
Finally I got a good discriminating reliable detector. I searched the TSGL posts. and saw that the original Tesoro patent allowed bottlecaps? anyone???

Good job on the coil!

Steel bottle caps are always tough. I always dig a few at the beach but most give you some sort of clue, usually a partially broken sound, but dig anyway!

Case in point: I went over to a co-workers house this week and he mentioned that he lost his wedding band a few years ago. I took my Nautilus DMCIIb for some reason. The third target I identified had a really crappy sound, almost like a bottle cap. Usually a gold band will have a sharp, narrow sound with the DISC channel louder than, and about the same time as the AM channel.

Not this one. I marked the spot and walked away. I though that it was a bottlecap. My friend dug it anyway. $##@$!! It was his ring .

[satdaveuk]

Coil inductance

Hi
I just wound the TX coil which was right to specs given on here, only diffrence is my gap between the two plates were 2/16th of a inch which is about 2.5mm. When I measured before luming the coil read 23.5 ohms resistance and 5.321mh inductance.
Now that I have lumed the coil with cotten doubled up I have the same resistance which was exspected but my inductance has shot up to 6.098, I was monitoring it as i was doing it.
I havent used any glue or shielding yet because I thought its best to chat with you people first for advise.
Hope all is well with everyone
Dave

[juka vk]

Hi everyone, i want to build this metal detector but.... i don't know from where i shoud read this thread, from the start or from the end. This thread is full of modifications.
Can someone make a new thread or PDF file with the best (but stabile) version of detector and with all modifications PLEASE !!!!

Greeting from CROATIA !!!

[simonbaker]

Hi
I just wound the TX coil which was right to specs given on here, only diffrence is my gap between the two plates were 2/16th of a inch which is about 2.5mm. When I measured before luming the coil read 23.5 ohms resistance and 5.321mh inductance.
Now that I have lumed the coil with cotten doubled up I have the same resistance which was exspected but my inductance has shot up to 6.098, I was monitoring it as i was doing it.
I havent used any glue or shielding yet because I thought its best to chat with you people first for advise.
Hope all is well with everyone
Dave

That always happens when you "bind" the coil (squeeze the windings together). Only experience will tell you how to plan ahead to get the final inductance you want. In your case maybe you can pull out extra windings (not so easy I've found after wrapping with thread).

It can change again when you shield and glue. It can change again when you set in the form if you deform the coil at all. Just something you have to get used to.

You can try to adjust capacitors to compensate after you coil is finally built.

-SB

[habitbraker]

Traced the PCB out. The only significant differences are below.

The only other things I see:

C14 and C17 are doubled - to 10uF.
R29 and R31 increased from 470k to 1m.
LM7808 decoupling removed.
CD4024 decoupling removed.
100uF decoupling added to U103.

Has anyone else built this from Silverdogs PCB yet?

Eduardos is on the left.

Don

Just wanted to tell everyone who owns Silvredogs green tgsl edu PCB.

R43 changed to 100k
R44 changed to 33k

Spoted only when I was assembling second one.

With these I got kindof broken sound and air depth reduced. Changed back to 330k and 2k2

[bernte_one]

Just wanted to tell everyone who owns Silvredogs green tgsl edu PCB.

R43 changed to 100k
R44 changed to 33k

Spoted only when I was assembling second one.

With these I got kindof broken sound and air depth reduced. Changed back to 330k and 2k2

is there something i should mod / change on the black/golden board too or is it finally ok?


another questions - who sells selfmade good made coil for tgsl here in europe (such like wiltran in above post)
i think i would buy one my biggest interest at tgsl at this moment is what can i reach with a good made coil instead of mine
if anyone has an offer please pm

[satdaveuk]

That always happens when you "bind" the coil (squeeze the windings together). Only experience will tell you how to plan ahead to get the final inductance you want. In your case maybe you can pull out extra windings (not so easy I've found after wrapping with thread).

It can change again when you shield and glue. It can change again when you set in the form if you deform the coil at all. Just something you have to get used to.

You can try to adjust capacitors to compensate after you coil is finally built.

-SB

Thanks for getting back to me Simon
In your opinion what would be the highest inductance you would go up to before going any further with this coil ie shielding etc.Am I right thinking that the conductvity will go up when adding a shield or is it just the tightning of the coils that does it? so in a nutshell does the shield its self either up the inductance or lower it, i thought the latter but i maybe wrong. As you said it can be offset with changing capacitor values but there must be a limit, and I dont want to end up with a machine not working to its full spec, I want to end up with the same results as the rest of you.
Also off hand what sort of capacitance reading should I exspect between the coil connections, before I lumed the coil it was reading about 27pf but after luming it jumped to around 70pf or more, but that maybe due to the batterys going flat on my meter and I was very tired.
My circuit is almost compleat, just waiting for the 2n2907 to be delivered from china.
By the way simon can I check the frequency of these coils without the pcb?
I have a very good signal generator with sweep plus 2 very good frequency counters plus a rather old but working dual beam scope.
If its possable I would be greatful if you can tell me in detail what to do because this stuff is new to me.
Many many thanks
Dave

[Qiaozhi]

Hi everyone, i want to build this metal detector but.... i don't know from where i shoud read this thread, from the start or from the end. This thread is full of modifications.
Can someone make a new thread or PDF file with the best (but stabile) version of detector and with all modifications PLEASE !!!!

Greeting from CROATIA !!!

All the information is here ->
http://www.geotech1.com/forums/showthread.php?t=15710

[simonbaker]

Thanks for getting back to me Simon
In your opinion what would be the highest inductance you would go up to before going any further with this coil ie shielding etc.Am I right thinking that the conductvity will go up when adding a shield or is it just the tightning of the coils that does it? so in a nutshell does the shield its self either up the inductance or lower it, i thought the latter but i maybe wrong. As you said it can be offset with changing capacitor values but there must be a limit, and I dont want to end up with a machine not working to its full spec, I want to end up with the same results as the rest of you.
Also off hand what sort of capacitance reading should I exspect between the coil connections, before I lumed the coil it was reading about 27pf but after luming it jumped to around 70pf or more, but that maybe due to the batterys going flat on my meter and I was very tired.
My circuit is almost compleat, just waiting for the 2n2907 to be delivered from china.
By the way simon can I check the frequency of these coils without the pcb?
I have a very good signal generator with sweep plus 2 very good frequency counters plus a rather old but working dual beam scope.
If its possable I would be greatful if you can tell me in detail what to do because this stuff is new to me.
Many many thanks
Dave

Hi Dave:

I believe the TGSL that dfbowers loaned me has a TX coil inductance of about 6.4 and RX coil inductance of about 6.9, and it works great, so you can see it can vary somewhat. It seems the most important thing is to have about .5 mH more in your RX coil than your TX coil, with the TX coil inductance near 6 mH.

But no guarantees, coils have been known to be subtle and some poeple claim they have good and bad coils with similar inductances. However, I think if you follow the basic practices for building the coils (like Ivconic, dfbowers, Max, etc.) you should be fine.

On the other hand, it really seems to be a good idea to make several coils so you can experiment and have a better chance of finding and fixing any mistakes.

No one I know of has really experimented with how far off you can go with coils and compensate with capacitors -- I'd like to try it, but it requires a good basement and coiling forming equipment and whirly-doodle target sweeper .

I can't remember if shield increases or decreases inductance... anyone? I think it is a minor effect compared to compressing the coil when you wrap it.

I'm not sure what you mean by capacitance between coil connections... maybe self-resonance of coil due to parasitic capacitance? (you have nice test equipment if so). In any case, I don't think it matters at all, very minor effect I imagine.

I don't think it's worth checking "self-resonant" frequency of coils since it is not the dominant resonance once the coil is in-circuit. Having said that, if two coils act differently even though they have the same resistance and inductance, it would be worth investigating.

If you lived next door we'd be in business because I tried to order five 2n2907's and by mistake ordered 5 bags of them.... but I'm short of 2N2222's....

I'm not the master builder of the TGSL, although I study the circuit a lot. For real building tips, dfbowers is a good one to check with for recent experience, and Ivconic's notes preserved by Qiaozhi in the Projects section.

When it comes to evaluating your TGSL, I've come to the conclusion that it is really important to get far away from all EMI to test maximum air depth. I have to drive 15 minutes into the mountains before dfbowers TGSL registers its maximum air depth.

Also, no one has really tabulated air-depth vs. ground-depth for standard targets with different quality models to see how important it is to get 30 cm air depth vs 20 cm air depth, for example. But we still like to use air depth as a way to evaluate whether we have built our TGSL similar to others.

It's kind of an ongoing project to get your MD working nicely, so allow for some troubleshooting experience. If it works great the first time, nice going.

Regards,

-SB

[turtlebowl]

Critical component values

Hello guys.
Want to know which components if any have to be matched or of high quality for Tesoro detector circuits.
I thought I read in here some time back that one of the caps needs to be a certain type or quality. Which ones??
How critical is matching the resistors and caps in the filter stages etc. ---will it still work if I do not match the components in the two different channels? Or just work better?
Do plain old cheap ceramic caps work?
I ask all this becuase occassionally we do not have the best quality componants on hand and I'd like to know if we need to order and wait for parts before building the circuit.
PHIL

[dfbowers]

Hello guys.
Want to know which components if any have to be matched or of high quality for Tesoro detector circuits.
I thought I read in here some time back that one of the caps needs to be a certain type or quality. Which ones??
How critical is matching the resistors and caps in the filter stages etc. ---will it still work if I do not match the components in the two different channels? Or just work better?
Do plain old cheap ceramic caps work?
I ask all this becuase occassionally we do not have the best quality componants on hand and I'd like to know if we need to order and wait for parts before building the circuit.
PHIL

I used plain old ceramic caps for filter and bypass caps, which are not critical at all. Other places you might want to consider polystyrene or polyester. For example, C1,C2 and C6 should be stable over time.

Then, be aware of where electolytics should be used.

As far as matching resistors, probably not that critical either.

I don't know how "correct" my selection is, but you can download the parts list here:

http://www.geotech1.com/forums/showthread.php?t=15710

I have built 3 so far without problems using this parts list.

You might want to see if Silverdog (Andy) can send you his parts selection as well.

Don

[satdaveuk]

COIL

Hi Dave:

I believe the TGSL that dfbowers loaned me has a TX coil inductance of about 6.4 and RX coil inductance of about 6.9, and it works great, so you can see it can vary somewhat. It seems the most important thing is to have about .5 mH more in your RX coil than your TX coil, with the TX coil inductance near 6 mH.

But no guarantees, coils have been known to be subtle and some poeple claim they have good and bad coils with similar inductances. However, I think if you follow the basic practices for building the coils (like Ivconic, dfbowers, Max, etc.) you should be fine.

On the other hand, it really seems to be a good idea to make several coils so you can experiment and have a better chance of finding and fixing any mistakes.

No one I know of has really experimented with how far off you can go with coils and compensate with capacitors -- I'd like to try it, but it requires a good basement and coiling forming equipment and whirly-doodle target sweeper .

I can't remember if shield increases or decreases inductance... anyone? I think it is a minor effect compared to compressing the coil when you wrap it.

I'm not sure what you mean by capacitance between coil connections... maybe self-resonance of coil due to parasitic capacitance? (you have nice test equipment if so). In any case, I don't think it matters at all, very minor effect I imagine.

I don't think it's worth checking "self-resonant" frequency of coils since it is not the dominant resonance once the coil is in-circuit. Having said that, if two coils act differently even though they have the same resistance and inductance, it would be worth investigating.

If you lived next door we'd be in business because I tried to order five 2n2907's and by mistake ordered 5 bags of them.... but I'm short of 2N2222's....

I'm not the master builder of the TGSL, although I study the circuit a lot. For real building tips, dfbowers is a good one to check with for recent experience, and Ivconic's notes preserved by Qiaozhi in the Projects section.

When it comes to evaluating your TGSL, I've come to the conclusion that it is really important to get far away from all EMI to test maximum air depth. I have to drive 15 minutes into the mountains before dfbowers TGSL registers its maximum air depth.

Also, no one has really tabulated air-depth vs. ground-depth for standard targets with different quality models to see how important it is to get 30 cm air depth vs 20 cm air depth, for example. But we still like to use air depth as a way to evaluate whether we have built our TGSL similar to others.

It's kind of an ongoing project to get your MD working nicely, so allow for some troubleshooting experience. If it works great the first time, nice going.

Regards,
Hi Simon
I got the 2n4444A from a company called Phenoptix on Ebay they were £1.79 for 10 incl p/p, They do post world wide and i recomend them due to the fact they dispatch same day and give follow up on delivery.
I think now after chat with you I shall carry on making this coil and logging measurements on the way as I go through the process for fucture references.
I got a very large reel of magnet wire so I will make many coils and pair up the best matches like often manufactures do when pairing up high end output transistors and valves.
I dont think there is a accurate sience to getting these coils identical everytime because even the room temp when making these coils will make a difference ie exspand and contract of the actual magnet wire and variations follow from there.
You know Simon when I purchase top end graphed LNBs from a manufacture for work, they are not manufactured top end, its just they are picked from a batch of say a thousand for there low noise figures etc, the rest of them go out as standard at half the price.
It also applies to matching pairs of transistors and valves in top end HI- FI equipment.
I think if we were nabours we would be in and out of each others workshops .
I will let you know my results
All the best
Dave

-SB

opps sorry I got confused

[simonbaker]

opps sorry I got confused

I think you are on the right track, and we all will learn from your experience too. Keep us posted how it goes.

Regards,

-SB