TESORO GOLDEN SABRE

[nakky]

R

R= HP=hat phone

[tiktak]

hi,

Thanks nakky for reply!
But I still can't understand please explain!
hat phone?

[Max]

Thanks nakky for reply!
But I still can't understand please explain!
hat phone?

Hi tiktak,
Ivconic maked a really good work on this PCB and version of GSabre.
It's intended to host a normal speaker and headphones socket too.
As in bought detectors! Nice.

I'm planning to make it too... soon, but have to find some time!

really simple... look at schematic... you'll see speaker 16ohm, right ?
That means just a small lo-imp speaker to be mounted inside the box.

Ok, R point is just connected to resistor 150ohm that goes to gnd.
You could use it to drive e.g. normal headphones connecting both channels to R point and P point.
Just use P, Q points as in picture for suitable (larger) speakers directly.

Meaning of having 150ohm in series with your phones is adjusting output impeadance to suitable value and also reducing audio volume... You could leave out 150ohm resistor using e.g. hi-imp headphones (a quality set of, with volume control(s))... but is your choice.

Better if you wire a jack-socket on panel and then have internal speaker normally connected to P-Q point... and then inserting phones jack disconnect internal speaker and connect phones to R-P point as described.

Very easy. Very useful e.g. if you need to work on noisy fields... and you need just headphone.

I've same stuff on bandido... think that this is A MUST on good (also homemade) detectors having double sound source, int. speaker and (optional) phones. Of course you could leave socket out... wire speaker directly... but I suggest you mount speaker socket and use headphones!

Best regards,
Max

[tiktak]

!

Thank you very much max.
I am glad that here are people that help on begginers!
Thats very nice.....
I am agree that this is a very good design indeed.
I still working on it almost ready.
I dont have much time lately to finish and test this.

[Qiaozhi]

Where is my errors?

Still can´t get the picture on how to calculate the coils. I had calculated with Calculate Coil program, but i got diferent values has posted.
On the picture i place on the program a calculation for a 110 mm radius coil, 0.25 mm wire and the result does not match around 6 or 6.5 mH, it gives 12.298 mH.
What i m doing wrong?
Regads
Nelson

Hi Nelson,

The Coil Calculator is designed to work for circular coils only, but the shape of the loops in the DD coil are more elliptical. As an approximation, take one of the loops and reshape it into a circle and then measure the "inner" radius. If you use this value in the calculator you will get a closer result. However, there will be an error because you will have changed the geometry of the coil. The inductance is also dependent on how tight you have bound the windings. Also - remember to use the inner radius, not the outer.

Here's my guess:
Assuming the loop circumference (in elliptical form) can be estimated as (pi * r) + (2 * r) for the circular coil, then r = c / (2 * pi) will yield the radius needed for the calculator.
This gives a radius for the loop (when reformed into a circle) of 90mm, which results in an inductance of 9.6mH. Changing the number of turns to 120 gives 6.2mH.
If you try reshaping the coil and then measure the real inductance, you can probably come up with a fudge factor that will make the calculator more useful for this shape of coil.

Hope this helps.

[Shahab]

Hi.

I'm going to build TGS circuit...

I will post here my problems later. Please help me...

Bye.

[Ultimate_Haze]

hi to all

Nelson, nice to here that you have better performance!
But I am londering which coil to make?
Here I see too many variants!?!?
What will you advice me?
Max,Leto and maybe ivconic when returns??!?!
To acive 22 cm in diameter finished coil size,on which size round former do you wind the coils?Or you just use D shape and wind on it?
I have 0,30mm copper wire here with varnish,what is the best coil arangement and windings turns?
In advance thanks

[Max]

Nelson, nice to here that you have better performance!
But I am londering which coil to make?
Here I see too many variants!?!?
What will you advice me?
Max,Leto and maybe ivconic when returns??!?!
To acive 22 cm in diameter finished coil size,on which size round former do you wind the coils?Or you just use D shape and wind on it?
I have 0,30mm copper wire here with varnish,what is the best coil arangement and windings turns?
In advance thanks

Hi Ultimate,
as I said before (somewhere) I've 3 working coils for my bandido, and tested them very carefully.
First is original tesoro's coil 9x8 spider.
Second is homemade concentric coplanar 8'' diameter round.
Third is homemade DD 22cm diameter coil (much like Nelson's one).

I have good performances with all of these!

9x8 and concentric round are really useful for pinpointing, really easy... and have similar behaviour on the field when you detect a target... no big differences between.

DD is another story... it gives me some (sometimes incredible) boost on depth and I could say that it gain maybe 8-10% in depth respect 9x8 I use too on the field. But pinpointing you'll do with tip of coil... not easy. Keep in mind that you lose some disc using DD coil... but really few... you need CC to get best disc (I've best with 9x8 ).

I made DD with 120turns for both tx and rx... wire is not so important... but you have to match 18-23 ohm resistance, and of course impeadance... but it's relatively easy (compared e.g. with my homemade CC 8'', that was not so easy to null). You could use 30awg wire... or 0.28mm diameter (with varnish).
What's truly important is nulling. A good nulling is a must for every tesoro clone coil... (and vlf-tr in general) cause if you can't get few mV peak-to-peak nulling you'll experience saturations, instability and loss of sens.

I suggest you making DD first cause it's easy to get it work in few time... then, if you want/have time/have wire to cut... try to make a good CC 8'' or
10''.

Best regards,
Max

[Ultimate_Haze]

hi

Hello,
Max!
I am glad that you help,but I can find 0,20 and 0,30mm for now.What will you advice me?With 0,30mm?Wich diameter?How many turns?
Thanks
I am now just testing with 0,120 and because someone told that lower D havs a higher resistance,I try with 70 TX and 75 turns for RX.What do you think will this work?D=21cm

[Max]

Hello,
Max!
I am glad that you help,but I can find 0,20 and 0,30mm for now.What will you advice me?With 0,30mm?Wich diameter?How many turns?
Thanks
I am now just testing with 0,120 and because someone told that lower D havs a higher resistance,I try with 70 TX and 75 turns for RX.What do you think will this work?D=21cm

Hi,
0.30mm is close to 29AWG (28.73mm) that have a resistance of 268.4024 ohm for 1km so 0.2684 ohm/m.
But this is intended for bare wires, without varnish.

If you have 0.30mm varnished you actually have something between 0.27 to 0.28mm diameter of internal conductor (varnish thickness could vary from manifacture to another, kind of insulations etc).

So I'll assume you have about 0.28mm diameter (bare) wire, so a 29AWG.

You need to match the tesoro range (18-24 ohm for both windings). and so it's relatively easy know how many turns you need if you know the former side lenght. Assuming you would like to build a 22cm DD coil you need a former that have something like 18cm diameter former (this depends much on how much you want the overlap zone is wide...) and then 56.52cm of circumference.

OK. Assume you want 22ohm of resistance you need :
22/0.2684 = 81.96 = 82meters
and so 82/0.5652 = 145 turns

D=21cm (diameter of former? seems big!) you get
circ = 21*3.1416= 66cm
so 82/0.66 = about 124turns to get 22ohm

You could use same number of turns for both TX and RX... but sometimes is better adding some turns (10-20) to RX making it out-tuned respect to tx.

Anyway, there are specs also for inductances on that coils.
When doing this stuff you need obtaining sililar to original frequencies on at least tx side... so you can change capacitor to match operating frequency.
On rx things are easy... is air-core transformer and you get right freq. (tx side one)...but also here you would change cap if notice low sens or bad disc.

"I am now just testing with 0,120 and because someone told that lower D havs a higher resistance,I try with 70 TX and 75 turns for RX.What do you think will this work?D=21cm"
I've tested also with smaller wires... but have bad results... of course you could match resistance as described above also here... thus reducing turns... but you'll get too far inductance from expected values to get it work.

Best regards,
Max

[Ultimate_Haze]

!

Thanks,
for your advice Max.
I just wanned to try other detector is it working also IB and because I dont have that tipe of coil here with me I decide to full around with this!

For Tesoro I will make like you say with 0,30 mm and 124 turns for TX and 145 turns for RX ?And using 18 cm former make 22cm coil afther, two windings are bened to D shape.

Are you talking about this 22N capacitator near TX and 15N near RX that must be mached if there is bad disck or poor sens,or I should place in search coil other capacitator with proper value?

[Max]

Thanks,
for your advice Max.
I just wanned to try other detector is it working also IB and because I dont have that tipe of coil here with me I decide to full around with this!

For Tesoro I will make like you say with 0,30 mm and 124 turns for TX and 145 turns for RX ?And using 18 cm former make 22cm coil afther, two windings are bened to D shape.

Are you talking about this 22N capacitator near TX and 15N near RX that must be mached if there is bad disck or poor sens,or I should place in search coil other capacitator with proper value?

Hi,
"Are you talking about this 22N capacitator near TX and 15N near RX that must be mached if there is bad disck or poor sens,or I should place in search coil other capacitator with proper value?"
yes, but not inside coil housing... not required. Just change they to suite needs, so having close to original freq. on tx side and, if needed, change on rx side other cap. Just do it on PCB directly.
Referring to tx:
0,30 mm and 124 turns if you use larger former diameter 21cm, more wire in one turn
and then 145 turns if you use 18cm diameter former ...to make windings.

You can make both tx,rx same number, but I suggest this:
wire 0.30 - former 18cm diameter - TX=145 turns RX=160turns
would be fine I think.

Best regards,
Max

[Ultimate_Haze]

Hi

Hi,
max thanks for making this clear for me!
I am very happy now.
I will ask some more stupid questions,but not today.

[Ultimate_Haze]

OP

Its look like I have one afther all!
Please MAX tell me what do you think I have came to disition to make as small as I can coil first.I now that I will make many before I reach what I want,so I have 12,6 cm former to wind coils on it/top cover from plastic CD's holder/.How many turns did you advace me to use for making good coil?
With this 0,30mm wire?
p.s.sorry for boring questions!But I wanna make shore I get it all and begin makin my own corect conclusions!
Thanks for helping
.


You rock

[Max]

Its look like I have one afther all!
Please MAX tell me what do you think I have came to disition to make as small as I can coil first.I now that I will make many before I reach what I want,so I have 12,6 cm former to wind coils on it/top cover from plastic CD's holder/.How many turns did you advace me to use for making good coil?
With this 0,30mm wire?
p.s.sorry for boring questions!But I wanna make shore I get it all and begin makin my own corect conclusions!
Thanks for helping
.


You rock

Hi,
try this configuration:

D=12.6cm (diameter of former? seems small!) you get
circ = 12.6*3.1416= 39.5cm
so 82/0.395 = about 208turns to get 22ohm

so try TX=210, RX=240

and let me know!

Best regards,
Max