TESORO GOLDEN SABRE

[Max]

could be the reason for this that I use 10kB marked potenciometers for sens and notch?
Or I should search the problem in coil?
I have conected as on the picture posted buy IVCONIC.
The ends of the two coils are conected to shields of both coils and from there buy shield and one cable they goes in to the ground marked point for RX coil and Tx coil.And the start of the two windings are conected to other two points for TX and RX?
I cant understand why?But according to the picture this is the way!
How did you conect this?

Hi,
10Kb means you have log. potentiometers... not good for MD (audio stuff) but they cannot be the cause of you problem...
I've used same of ivconic config on internal of my DD housing, everything the same. Just one GND (copper jacket) conductor goes from coil to PCB.

Best regards,
Max

[tiktak]

could be the reason for this that I use 10kB marked potenciometers for sens and notch?
Or I should search the problem in coil?
I have conected as on the picture posted buy IVCONIC.
The ends of the two coils are conected to shields of both coils and from there buy shield and one cable they goes in to the ground marked point for RX coil and Tx coil.And the start of the two windings are conected to other two points for TX and RX?
I cant understand why?But according to the picture this is the way!
How did you conect this?

[Max]

hi Thanks,
But I try this before I post my question.When I disconect the coil no sound at all!
I will try with another coil!

Hi,
it's normal...
when you disconnect coil you stop oscillations... and then voltage converter , for negative rail, stops working too... and so all the thing appears dead.

That's ok. Try switching in disc mode... and note if battery-check stops after 3-4 seconds and you get then no sound.

Best regards,
Max

[tiktak]

hi

hi Thanks,
But I try this before I post my question.When I disconect the coil no sound at all!
I will try with another coil!

[Max]

Hi,
I just try to test my pcb,but there is constant loud audio taht dont stop!@!!!!
Please tell me what could be the reason?I mean I now that there should be this kind of sound,but for few seconds!And this dont stop screaming!
Help please

Hi tiktak,
think you are in all-metal maybe... OK in all-metal when you switch it on you get first battery-check tone... then after 3-4 seconds it must stop... but then you have output from detector (all-metal threshold) so two solutions:

- regulate sens at minimum... your sound must drop in volume if everything ok
- switch to disc mode, sound will vanish if everything ok

Batt-check must be performed in disc-mode cause you better understand when tone stops even if have a messed up threshold...

Best regards,
Max

[Max]

Hi Ivconic & Max & Nelson & all

I'm going to finish TGS circuit and want to build the RX & TX coils.

My questions:

1.Nelson,Which coil did you use on local park?

2.Ivconic,What is your suggest for best result coil under the ground(NOT on

the air)?

And Please write abaut tuning Pots & Volumes?

Hi Shahab,
think that we treated before... anyway I use with success this DD.
Outer diameter of DD coil = 22cm
Wire diameter/gauge 0.25mm(30AWG) measured without varnish (0.28 with varnish)
Tx turns = 120
Rx turns = 120 (but you maybe would use a bit more 125-135)
Resistance of both around 22ohm (must be from 18 to 24ohm)

Null as well as you can... read previous posts for how to.

Then test before without shields and see how it goes... if you get e.g. 25cm for 1cm coin you are on the right way. Then add spiral of foil... as shield as described.
Fix everything in housing using epoxy.

I can detect 1eur coin at 30cm underground with that coil and bandidoII. Coil would be even better on GS.

When you use it on real field make first a good geb tuning using trimpot on pcb... you haven't to see any audio change when rising or lowering the coil to soil from e.g. 30cm to 10cm... but you have to rise and lowering it fast not slowly. In test bench is better avoid messing with ground balance too much... just use a ferrite round core... you must set up trimpot to ignore it at 5cm from center of coil. You need detector doesn't sound with it... then exercize with disc/notch. For an idea look at bandido user manual... GS isn't much different but as Notch that bandido haven't.

Then go to one good test field and play for 2-3 hours... and you'll master the beast!

Best regards,
Max

[tiktak]

Hi

Hi,
I just try to test my pcb,but there is constant loud audio taht dont stop!@!!!!
Please tell me what could be the reason?I mean I now that there should be this kind of sound,but for few seconds!And this dont stop screaming!
Help please

[Shahab]

Hi Ivconic. Well this really looks like a joke, today i took my GS to a local park and after 30 minutes i got losts of coins with it. Also it shows me that GS is really a good machine, solid sound on coins and good discrimination too, same has you. I also compared with my ACE 250 and i must recognize that golden sabre is much much better. So the circuir is really working has a champ.
The only think that still keep me busy, is a good coil, to allow me to get coins and others stuff deeper.

Hi Ivconic & Max & Nelson & all

I'm going to finish TGS circuit and want to build the RX & TX coils.

My questions:

1.Nelson,Which coil did you use on local park?

2.Ivconic,What is your suggest for best result coil under the ground(NOT on

the air)?

And Please write abaut tuning Pots & Volumes?

[Max]

Yakety sax !

the background theme ??? I have it in mp3!

here is the midi (would be nice on the phone!!!)

[Max]

ivconic or Max.

When you place the foil on the coils, does it have an effect on inductance or impedance or values are the same when you just have the coil without the foil?

Thanks
Nelson

Hi Nelson,
you are doing a good work on your coils. Let me say that I think you'll gain great experience and skills making your coils. Same thing happened to me.
As ivconic stated many times... inductance matching is not so important if you know what are you doing... just you need to match the tx operating frequency as expected (but also this point you could even change, then making minor changes e.g. on some caps in the circuit) and get a good nulling on rx. Both tx, rx matching expected resistance values within 10% tollerance.
And all your coils will rock.
To answer your question:
I always noticed that adding shield increase inductance. Adding foil you get a increase of inductance, of course. Also with aluminium/mylar I use is the same... but I get less added inductance that way (al film is really thin).
You have to remember leaving always the gap in the shield and have two different (insulated) shields for both coils. Then just use two bare wires to connect to gnd point at cable inside the coil housing. Remember, do not create closed electrical paths between the two shields, this would affect performance, so insulate each other using e.g. tape or paper.
Another trick to avoid too capacitive or inductive added effects is to space the shield from the wound. It's described on BBSailor article on fast monocoil for PI, but principle is always good if you need less cap. or ind. disturbance on shielded coils. Use polyethilene spirals for this... but in VLF just you don't need that stuff I think. I never used in VLF, but only PI coils.

Best regards,
Max

[nelson]

My final test for today.

I made a 28 cms coil, but not with 120 turns for TX. Just 80 turns. Inductance is 5.9 mH and resistance 21.6 ohms. Tomorrow i ll make RX coil with 85 turns, impedance must be around 20 ohms has i see on my calculations.
More later.
regards
Nelson

ivconic or Max.

When you place the foil on the coils, does it have an effect on inductance or impedance or values are the same when you just have the coil without the foil?

Thanks
Nelson

[nelson]

ivconic or Max.

When you place the foil on the coils, does it have an effect on inductance or impedance or values are the same when you just have the coil without the foil?

Thanks
Nelson

Hi Ivconic. Well this really looks like a joke, today i took my GS to a local park and after 30 minutes i got losts of coins with it. Also it shows me that GS is really a good machine, solid sound on coins and good discrimination too, same has you. I also compared with my ACE 250 and i must recognize that golden sabre is much much better. So the circuir is really working has a champ.
The only think that still keep me busy, is a good coil, to allow me to get coins and others stuff deeper.

I am really confused now, don´t know if i finish the 28 cms coil with 11.43 mH for TX, 120 turns, 0.25 mm wire, 30.2 ohms of resistance and same form has you did or i should take less turns to reach the correct impedance (19 to 22 ohms).

Here i m posting a sketch of my coil details. I also check resistance with another multimeter that shows 31.6 ohms, so the problem is still on the coil.

Anyone that can help i ll really apreciate that.

Best regards

Nelson

[nelson]

Hi again. I also have calculated two coils for TX. One with 11.4 mH, that is the one i have with 120 turns on a 28 cms form. The other is for 6 mH and turns is around 86 for same form dimension.
This shows me that my measurements are correct, but still don´t know where is the problem. See my previus post that show my coil form and dimensions. Are this correct?

See the simulation below.

Regards

Nelson

Hi Ivconic. Well this really looks like a joke, today i took my GS to a local park and after 30 minutes i got losts of coins with it. Also it shows me that GS is really a good machine, solid sound on coins and good discrimination too, same has you. I also compared with my ACE 250 and i must recognize that golden sabre is much much better. So the circuir is really working has a champ.
The only think that still keep me busy, is a good coil, to allow me to get coins and others stuff deeper.

I am really confused now, don´t know if i finish the 28 cms coil with 11.43 mH for TX, 120 turns, 0.25 mm wire, 30.2 ohms of resistance and same form has you did or i should take less turns to reach the correct impedance (19 to 22 ohms).

Here i m posting a sketch of my coil details. I also check resistance with another multimeter that shows 31.6 ohms, so the problem is still on the coil.

Anyone that can help i ll really apreciate that.

Best regards

Nelson

[nelson]

Hi Ivconic. Well this really looks like a joke, today i took my GS to a local park and after 30 minutes i got losts of coins with it. Also it shows me that GS is really a good machine, solid sound on coins and good discrimination too, same has you. I also compared with my ACE 250 and i must recognize that golden sabre is much much better. So the circuir is really working has a champ.
The only think that still keep me busy, is a good coil, to allow me to get coins and others stuff deeper.

I am really confused now, don´t know if i finish the 28 cms coil with 11.43 mH for TX, 120 turns, 0.25 mm wire, 30.2 ohms of resistance and same form has you did or i should take less turns to reach the correct impedance (19 to 22 ohms).

Here i m posting a sketch of my coil details. I also check resistance with another multimeter that shows 31.6 ohms, so the problem is still on the coil.

Anyone that can help i ll really apreciate that.

Best regards

Nelson

Hi ivconic,
"read my lips; C B E !!!" but using that sombrero I cannot trust you !

BTW sometimes I feel like Benny Hill too here...???
we have to share the avatar!

Best regards,
Max

[ivconic]

Yakety sax !

Yakety sax !