IGSL

[nakky]

My 2 cents.
Because Ivconic is back on the Forum.
10x10 cm.
Not checked.

[nejdet]

IGSL

Thank Ivconic

[ivconic]

Two of the spots marked in red on CD4044 - U2 are to be connected to D1 and D2.
D1 goes to pin 4 and D2 goes to pin 5 of U2. The pad for pin nine was for Ivconic's earlier version. You can use it but will give you a higher tone.

Jerry

Yes. I didn't connected those, because i left it to subjective choice. Choose 5&6 or 5&9 ... or 6&9 if you like. Experiment. Also there are more choices, you may include some other 4024 divisions if you like.

[ivconic]

Good day Ivkoni. I want to ask does it matter where you turn on the monitor and had to symmetrical to the Faraday shield. Faraday shield the receiving coil is not symmetrical with inclusion. Thank you! Good day Sorry for bad English

It doesn't matter. You may place inclusion, gaps and naked wire wherever you want. Wherever is convenient to you - you place it. It will not affect performances...

[nejdet]

IGSL

Good day Ivkoni. I want to ask does it matter where you turn on the monitor and had to symmetrical to the Faraday shield. Faraday shield the receiving coil is not symmetrical with inclusion. Thank you! Good day Sorry for bad English

[Jerry]

http://b1107.hizliresim.com/11/7/27/391.jpg
I could not understand what this place is a kind of help please

Two of the spots marked in red on CD4044 - U2 are to be connected to D1 and D2.
D1 goes to pin 4 and D2 goes to pin 5 of U2. The pad for pin nine was for Ivconic's earlier version. You can use it but will give you a higher tone.

Jerry

[dfbowers]

And; PCB side....

Ivconic,

Excellent artwork and a great contibution!

Don

[cnckecgo]

http://b1107.hizliresim.com/11/7/27/391.jpg

I could not understand what this place is a kind of help please

[bernte_one]

nice drawings many thanks

[ivconic]

And; PCB side....

[ivconic]

hello

if the decision falls to musketeer coil- is anyone able to post guide for coil wiring
(like tgsl coil making) with nice shematic (picture) ? plz

Something like this...

[bernte_one]

hello

if the decision falls to musketeer coil- is anyone able to post guide for coil wiring
(like tgsl coil making) with nice shematic (picture) ? plz

[dfbowers]

Agree; Minelab coils can be bit more expensive for a typical hobbyst budget. Some people can afford and some others can not.
So it is good to check majority opinion - i agree.
Silverdog, do collect orders before you decide which version to make.
In case majority still wants to make last version and most of them can not find original Minelab coil - there is a way to make it!

Already known 255x137mm "D" form (for 27cm DD coil):
- TX=1mH, 42 to 45 windings, wire 0.5 to 0.55mm
- RX=14.7mH, 165 to 175 windings, wire 0.22 to 0.25mm

Resistance at IGSL is not issue, as it is at Musketeer (wont oscillate if TX is over 2.5ohms) - so do not worry about it.

Both "D" shaped coils are shielded with Faraday cage. Both cages are connected together to TX ground lead (in coil) .
Cable from coil to detector is double coaxial (as on original TS coils).
Rx leads are "hot" and "shield" - but that "shield" is not connected with main GND (shields) in coil housing.
Also RX "shield" is not connected on pcb gnd - it is connected just to inverting input of LM833.
Coils are nulled to have minimum possible residual voltage (measured on original TS 1000).

I am suggesting last IGSL version and Minelab coils (or copies) because that version is showing really better performances.

But also there are number of people who already made TGS/TGSL and suitable coil for it.
So those people can just make first IGSL version and use already made coil for TGS/TGSL.

So ... it is hard to predict numbers of which pcb would more likely to be wanted!
That's why is smarter to start some sort of voting and collect majority opinion.
Cheers!

Ivconic,

I will undertake the challenge of duplicating your "Minelab" coil above. I have to!! It does look like the Tesoro Cibola/Vaquero coils are just about the same inductances as the Minelab coils as well.

I tried unsuccessfully to breadboard the oscillator section and get it to run with my Cibola coil this evening. No matter what, I could not get the Tx Amplitude over 2v. Not giving up yet.. I'll start fresh tomorrow!!

Don

[ivconic]

Ivconics, I just finished tr coil 1mh, and it peaks my curiosity thicker wire for tr coil, bigger transistor thus more power for tr thus explaining better performance over TGSL! right?

TGSL could use a bit more TX power - i agree. That's why i suddenly decided to mod IGSL just few days after i made first version!
But my goal was not to gain extreme high power - but just a bit more than on TGSL, enough to experiment with "hysteresis issue" i met on previous TGSL works.
My initial motif was simple - but later turned that it will gain me more benefits than i could anticipate at the beginning!
(good things are almost always happening without direct intentions!! )
So.. along with solved previous issue - i also got adjustable TX, much more power if i need, better filtration, interesting frequency, chance to use original coils (variety of those made for Musketeer) ....etc..etc..
So... more TX power will give better performances - that's for sure.
But be careful! Do not expect miracles.
On contrary; boosting up TX to much may cause unwanted side effects.
If i remember good; Qiaozhi elaborated very nicely pro&contra of boosting TX, somewhere on these forums. Would be nice to find those posts.
Point is: there is not much benefit from boosting TX power to much - more likely it will turn contra productive.
But here, at TGSL (IGSL) all we needed was just a bit more power - not much.
TGSL already worked very well, already gained good depths.
So.. you will notice that 220 trimmer (P5). Adjust it just to get nice sinus on TX out.
It's been experienced in the past that good TX at TGSL can even produce a small "notch" on the top of the sinus, so if you want (literally) more power than on TGSL - just rise a bit more amplitude with P5 to provoke appearance of that small "notch" on the top of the sinus.
Experiment more if you want. Rise up amplitude to maximum level and check overall behavior of the GEB and Disc.
You will easily establish the right adjustment by checking those, during experimenting with P5.
All you need is some scope and .. good will!

[simonbaker]

I just spotted this!? Must be that i gone blind lately!?
Yes; it is good question!
But than i am not sure about swing at some opamps? 1V difference (on positive side) seems not relevant.... but!
Pity, i can't elaborate that right now (for each claim i could make right now - you would expect me to prove on examples, right?)
It's been a while since i was whole in TGSL "business" - many things i forgot!
Making IGSL i just took the good old (and many times proven) "symmetry" principle from TGS/TGSL.
Simply didn't wanted to waste time on "philosophy" and reinvent another way to supply those opamps.
Also i am sure that there is a reason for origin Tesoro decision to use such "symmetry" as +8V/-6.2V in many of their designs.
It could be much simpler, otherwise.
It is much easier simply to "split" battery voltage to half... and there you go with "symmetry"!
Just like it was done at White's Classic....
But i am afraid that TGS/TGSL and now IGSL will not work "in range" with such "symmetry"...
It is indeed very interesting question. I would like to elaborate it in details later... or on some other topic maybe...

Yes I wonder too about symmetry and whether we can use other V+ and V- voltages -- I think it would work the same with just tiny adjustment to sensitivity circuit (or just ignore it). Maybe audio volume change slightly.

Isolation of oscillator is fair point also, although doesn't seem to be problem with TGSL.

Anyway, 7809 is small part, not expensive! I just like to ask circuit questions to learn more. Important thing is we have a PCB and lots of interest, thanks!

-SB