Tesoro Bandido II

[ivconic]

Hah!
Finally i got one original Tesoro, just for me!!!
It is Bandido II (not uMax).
It is very cute small machine. Extra lightweight! Two 9V batteries connected in parallel - providing more current and last longer.
Coil 20cm.
Extra good discrimination! Almost the same as on my TGSL's.
Frequency exact 10.02 kHz!
Excellent All Metal mode - static, nonmotion. Excellent! Autotune also works excellent. Manuall GEB works good, but not rejected 10cm ferrite rod totally. It reject it very good, yet very short cracks appears when rod is about 5cm away from coil surface...hmmm..this could lead me to learn to adjust GEB on my TGSL's a bit "softer" in future. Clay,hotrocks and blacksand rejected 100%.
Very good behavior overall.
Yet..... air depths are not so great! Same old, famous 1e coin, at same setup on the plastic bench (setup i always use to test all detectors) it is detecting bairly at 23cm in air. Just to remind; TGSL, with 27cm DD coil, same coin, easilly "eating" at 32 to 34cm!
I tried to keep all adjustments the very same on Bandido II as on my present TGSL. And i just did testings on both at the same time. Very simillar except air depths on 1e coin. So...this Bandido will need new coil very soon!
Next week or two i intend to perform some more detailed checks, measurements and analyze...
Enjoy!

[Max]

Hah!
Finally i got one original Tesoro, just for me!!!
It is Bandido II (not uMax).
It is very cute small machine. Extra lightweight! Two 9V batteries connected in parallel - providing more current and last longer.
Coil 20cm.
Extra good discrimination! Almost the same as on my TGSL's.
Frequency exact 10.02 kHz!
Excellent All Metal mode - static, nonmotion. Excellent! Autotune also works excellent. Manuall GEB works good, but not rejected 10cm ferrite rod totally. It reject it very good, yet very short cracks appears when rod is about 5cm away from coil surface...hmmm..this could lead me to learn to adjust GEB on my TGSL's a bit "softer" in future. Clay,hotrocks and blacksand rejected 100%.
Very good behavior overall.
Yet..... air depths are not so great! Same old, famous 1e coin, at same setup on the plastic bench (setup i always use to test all detectors) it is detecting bairly at 23cm in air. Just to remind; TGSL, with 27cm DD coil, same coin, easilly "eating" at 32 to 34cm!
I tried to keep all adjustments the very same on Bandido II as on my present TGSL. And i just did testings on both at the same time. Very simillar except air depths on 1e coin. So...this Bandido will need new coil very soon!
Next week or two i intend to perform some more detailed checks, measurements and analyze...
Enjoy!

Hi,
sure. It's original coil... original coils, expecially concentric from them are not so good... just average. They are good at disc (phase shift) but performances are weak with them.

I have 8x9'' and very unsatisfied with it... unless in trashy sites... where it's good having less depth but more consistent disc.

What to say... make coils for it, you'll be surprised I think.

With my homemade coils my bandidoII clone works much better than with original one.

Not a size only issue, but nulling I think is too worse in original coils.

It's weak... good to have few falses, very good disc , but lose too much in performances on soil.

That's why people complain with Tesoro's weakness , at least with some uMax etc...

COILS! they can make better. These coils costs like others... but others are often much better and give much better results on soil.

You can teach them I think...

Kind regards,
Max

[ivconic]

Yes, this coil will do excellent job on trashy and bushy terrains (plenty here). Not the huge depth that we need always. It is convinient to involve it under trees, in bushes, between rocks, in holes. So it will do the job just fine. And another , DD i will make for other cases where i will need more depths.
What to say? I already have nice Musketeer complet, today also got 10" DD coil for it, TS1000. Now i have 18cm,25cm,36cm and 45cm coils with Musketeer Colt. It covers everything, every possible case. And it is very deep.
Time to extend Bandido with another coil! Already!? Why waiting..!

[Ultimate_Haze]

Congratulations.
Now your collection is more complete.And a lot of questions will find answer.

[ivconic]

Ok. For those already involved in TGSL making; this is very interesting!
I just performed some small epxeriments.
Since i already have Bandido II with original 8" (brown) coil and also i do have one of my TGSL handmades, i decided to exchange coils between those two and perform some measurements. So...

* TGSL i used in this is last version with BD140 at audio.
* TGSL coil is already explained 27cm DD coil (my handmade).
* TGSL with its coil detects 1e coin at 32cm in air, Disc at "4" and Sense to maximum. No chatters, no falses, ferrite rod fully rejected.
* Bandido II with 8" coil detects same 1e coin at 22-24cm in air. Disc at "4" and Sense at maximum. No chatters, no falses, ferrite rod producing rare short "cracks" (not disturbing and not significant).

Now...

Experiment 1.

With use of 2 extra connectors (suitable) i connected original Brown 8" coil to my TGSL handmade.
- Residual voltage measured at RX wires from coil (disconnected from detector) is 3.4mV (range AC~ 200mV)
- Frequency is 14.4kHz
- 1e coin cleary detected at 24cm in air, under same uniform conditions.
- Ferrite rod fully rejected, no cracks, no chatters, 100% stabille and calm.


Experiment 2.

With use of 2 extra connectors (suitable) i connected my 27cm DD handmade coil to original Bandido II detector.
- Residual voltage measured at RX wires from coil (disconnected from detector) is 0.0mV (range AC~ 200mV)
- Frequency is 9.5kHz
- 1e coin cleary detected at 31cm in air, under same uniform conditions.
- Ferrite rod CAN NOT BE rejected. GEB trimmer turned fully in both directions, no influence on ferrite rod rejection. Iron is rejected 100%.


Datas:

- My 27cm DD coil ; TX=6mH, RX=6.5mH
- 8" Brown coil ; TX=5.63mH, RX=6.22mH

I was lazy to open Bandido II and check if there is some extra GEB trimmer inside. First time when i opened it i spotted another trimmer there... Maybe ferrite rod rejection can be achieved if there is another GEB trimmer inside. Will check these days...

Conclusion;
IT IS ALL ABOUT COIL!


8" Brown Tesoro coil is C.C. coil. It's performances are what they are; 22-24cm on 1e coin in air....so..never mind if it was tied to Bandido II or TGSL, performances looks exactly the same.
27cm DD handmade coil is DD coil. Also it's performaces are what they are; 30-34cm on 1e coin in air....so..never mind if it was tied to TGSL or Bandido II, performances looks exactly the same. Banido II is obviously much deeper and have "stronger" discrimination with this coil.

Considering sizes and setups of coils...i think both coils are just very good.
Any other conclusions.....it's yours to establish.
Cheers!

[ivconic]

Small, logical mistake here:
"...same. Banido II is obviously much deeper and have "stronger" discrimination with this coil..."

It is "..obviously much deeper ..." then it was with original 8" coil, but it is not deeper than TGSL with that (27cm DD) coil. Differences are 2-3cm in TGSL favour. This is not important, neither significant. I think Bandido looks refined a bit than TGSL, which is normal. It is made on small smt ceramic pcb with newer and better opamps. TGSL is still handmade with discrete components.
So it is normal to expect better S/N ratio at Bandido II.
But this experiment is aimed to show that coils can be exchaged between these older Tesoros without any problem. Not problem at all. Also there is not any secret in TGSL which makes it esspecially deep. With 8" coil TGSL is not deep at all. On other hand; Bandido II with larger DD coil is much deeper than it was with smaller 8" coil. So... everything is in coil! Coil, coil and nothing but the coil!

[Max]

Small, logical mistake here:
"...same. Banido II is obviously much deeper and have "stronger" discrimination with this coil..."

It is "..obviously much deeper ..." then it was with original 8" coil, but it is not deeper than TGSL with that (27cm DD) coil. Differences are 2-3cm in TGSL favour. This is not important, neither significant. I think Bandido looks refined a bit than TGSL, which is normal. It is made on small smt ceramic pcb with newer and better opamps. TGSL is still handmade with discrete components.
So it is normal to expect better S/N ratio at Bandido II.
But this experiment is aimed to show that coils can be exchaged between these older Tesoros without any problem. Not problem at all. Also there is not any secret in TGSL which makes it esspecially deep. With 8" coil TGSL is not deep at all. On other hand; Bandido II with larger DD coil is much deeper than it was with smaller 8" coil. So... everything is in coil! Coil, coil and nothing but the coil!

Hi,
yes, it is.

It's coil... that's why I wrote you can teach them!

The standard coils are not so good, and you saw this by that experiments.

They are good in trashy areas, but fail when compared to pushed performances of good homemade coils. Expecially DD kind.

But, you'll find the same using OO coils or even concentric homemade... is much about tuning/nulling of coils.... and size of course.

They , instead, focus much more on "stability" and perfect discrimination (so exact phase shift) more than pay attention to absolute performances.

That's why people complain about these MDs... lack of performances respect competitors.

Indeed the MDs are very good... they just make average coils for them!

The bandidoII is better than TGS/TGSL if pushed more on performances... that means shield critical parts and use lower noise amps....

Problem you must consider is that bandidoII has extended disc ED180... means it could be impossibile e.g. make it silent on ferrite rods.

You have manual geb pot (multiturn) to get it balanced but still setup is not as quiet as with TGS.

About disc... you have to put that a not at min setting... otherwise you'll detect iron also.

Kind regards,
Max

[ivconic]

Yes i just checked; there is extra 100K GEB trimmer inside the box, on pcb. It need to turn it just 1-2mm in one direction and i got much better situation!
Now...; Bandido II with my homemade coil is acting almost the same on ferrite rod as it was with it's original coil! Splendid! Ferrite rod now still not rejected totally, but now only rare and short "cracks" on it! Detection...i just checked it again, 32cm on 1e coin! And when rear Threshold control adjusted to maximum...wow! Extra good audio response on coin, in Disc mode! Wow! I am very satisfied! Better response than TGSL! Sharper and more noticeable response!
Finally...yes, it was all just about the phase. My 27cm coil is obvoiusly balanced a bit different than original 8" and it needed a bit adjusting with inner GEB trimmer to get excellent situation now!
So... now i can cleary say it is really about coil dimensions and type!
No Max....by no means i could'nt be smarter than Tesoro guys! I can only wish!
I think they wanted stabillity and accuracy with small c.c. coil. And it is for real very stabille and accurate, no doubts!
More depth to gain is easy - just make larger coil and make it DD, for known reasons.
Look for example the Tesoro Tejon. With it's primary coil in package it is pretty ordinary machine. Nothing special. But when you hook up it's larger DD coil....hell... it is extra deep beast!

So.. yes, now we can count on option to make larger and deeper coils for some of Tesoro models, no problem at all.
I wish old models to get new life with new coils, simply cose those machines are still valueable and pretty useable.

[simonbaker]

This is more interesting information about coils, good to learn.

I am wondering... if make target smaller and smaller (smaller coins), can 8" coil detect deeper than 27 cm double-D for some size?

Also: if target is on surface of ground, or maybe very shallow in ground, how do audio beeps compare between 8" and 27 cm DD coils? How easy to locate target?

-SB

[ivconic]

For shallow targets smaller coil is more suitable. Better pinpointing and same response as larger coil. Smaller coil can reach some point on soil where larger can't. So smaller coil is very usefull. Best case is to have several coils for each detector. 27cm DD coil hooked on older Tesoro is really deep enough to compete modern detectors. Everybody, having older Tesoro should consider making larger coil - worth of effrot for sure and repays all invested in it. Brings new life to old machine.

[WM6]

Everybody, having older Tesoro should consider making larger coil - worth of effrot for sure and repays all invested in it. Brings new life to old machine.

What about more recent Tesoro and bigger DD coil? Any experience?

[ivconic]

What about more recent Tesoro and bigger DD coil? Any experience?

Yes; new line of Tesoro coils differs much from older. So as i pointed few times on other threads; Vaquero and Tejon (only those i tested) are having different philosophy. Coils measured giving funny results; approx 1mH (TX) and 14-16mH (RX)!!! So...reminds on Minelab coils for Relic Hawk and Musketeer. And i connected 39cm coil for Relic Hawk to Vaquero just for testing. It is working excellent! Everything is on right place, phase too !???
So...should make coil with those inductances and than balance it directly to some of newer models using previously described methods.
Regards!

[Max]

Yes; new line of Tesoro coils differs much from older. So as i pointed few times on other threads; Vaquero and Tejon (only those i tested) are having different philosophy. Coils measured giving funny results; approx 1mH (TX) and 14-16mH (RX)!!! So...reminds on Minelab coils for Relic Hawk and Musketeer. And i connected 39cm coil for Relic Hawk to Vaquero just for testing. It is working excellent! Everything is on right place, phase too !???
So...should make coil with those inductances and than balance it directly to some of newer models using previously described methods.
Regards!

Hi,
I think they leave the uMax series for good... and made similar coil to Minelab Relic Hawk, used also similar approach at tx I think.

That's simple... RH recipe was/is good so why still messing with weak TX stage and low battery consumption ???

People wanna light MDs, wanna batteries last long... but more than anything they wanna don't miss stuff cause of weakness of tx or coil design.... they wanna maximum depth... that means maximum chance to recover something can not just surface items.

Maybe the lesson was learnt... and you can mount a RH coil on a Vaquero without any mod... what a case!

BTW I cannot put hands on such a coil... to test again my RH board... dang!

Kind regards,
Max

[ivconic]

Vice versa...ha,ha,ha...you can look for Tejon, Vaquero or Cibola coil and use it with your RH!

[daverave]

i want to try and make a tesoro bandido micro max..... but ive never made a motion coil before so is it easy to make and what are the inductances of TX & RX