Ultimate Bandido PCB?

[driscoll]

Good evening M. Magman116,

Your promises are very interesting, but for now we could not appreciate your talent.

Where are your shematics ?

Where are your PCB's ?

Regards

[kt315]

I can still post a schematic for a great detector if people would like to make them. This one is very easy to build and is fairly hi-performance.

-C

no need. keep these accurately in one place. BTW this agenda is very oldie. very very oldie, from 2000 year.
if you are sleeping up in one day to redesign XLT... call me. I will help you with all people in our part of world. your potencial must NOT diffuse off around on the waste of your great time.

[joecoin]

I'm not sure how many participants on Geotech would care if the PCB was an exact physical replacement for the original PCB. In my case, it would not matter since I don't have the original machine. I would be interested in the board in any form.

[Sven]

Please give us something to play with

many of us have been waiting patiently since July since you posted that you would post schematics etc.

[Magman116]

Sean,

Thanks for the offer, but we design our own preamps that are as low as noise as possible with today's components. Typically we will make sure the preamp has a little lower noise than the coil. We do have a design where we had to parallel many low noise transistors to get the noise floor lower. This is with an extremely sensitive detector.

I should know tomorrow if we are going to make the new uMax replacement PCB.

I can still post a schematic for a great detector if people would like to make them. This one is very easy to build and is fairly hi-performance.

-C

[Sean_Goddard]

I'm glad at least ONE other person agrees that SOME of Tesoros designs are poor in as mucch as bed design practices are used. Shows a certain level of inexperience on the part of some of their designers I think.

I've wondered about impedence matching the stages, but have never found time to do the calculations or sims. THEORETICALLY it should make a much quieter machine if done this way.

Also Tesoros demodulators are too primitive. Best to invert the negative half too and demod BOPTH parts of the incoming signal. I also wondered about amplifying and using attentuators to boost the S/N ratio on the front end, but again, I've not run the sims. Take the 4053 based demod Andy Flind uses in the Magnum, VERY low noise and VERY wide dynamic range, unfortunately they are copyrighted Andy, and this has passed to his widow, so need permission to use them in a commercial design (I can get you this if you need it though).

I would value your opinion on this matter, let me know what you think.

[Magman116]

Sean,

We are still thinking about remaking a PCB to fit the uMax enclosure. While it would still look like a Tesoro, it would not be the same electrically. We have been analyzing the Bandido II uMax and came to the conclusion it would not be a great improvement to make a mod for the existing PCB as there is excessive noise in other circuit besides the preamp and the signal processing is, I hate to say it, a poor design.

So, we are trashing are old PCBs and should be making new PCBs that replace the Tesoro PCBs. Also, we might add a LiPo battery pack for increase power to the coil.

-Chris

[Sean_Goddard]

Why not post the schematic here and sell the existing PCB's? I'll buy one from you if the price is reasonable.

How much built & tested?

[Magman116]

Today we checked out PCBs

The PCBs we had for this circuit measure 5.5" x 3.25". They were originally designed for a 6.25" x 3.5" x 2.125" enclosure. I believe it was a Crown Royal L202-ND enclosure.

If enough people were interested we would remake the PCBs to the size to fit the Tesoro uMax enclosure.

This circuit will provide the following basic features:

Adj Sensitivity
Adj Discrimination
Adj Ground Balance
Saltwater Mode
All metal / discrimination
Option for TID
Uses 2x 9V batteries
Current consumption 12mA
8KHz operating Frequency
real-time detection

So, it provides enough controls for it to be comparable to the Bandido.

-C

[Magman116]

What would you charge if I sent you my Bandido to have this work done.

This would not be work done to your Bandido, but a new circuit with the same basic functionality as the Bandido.

The main limits in with the Bandido are the RX preamp, the transmit oscillator and the coil design.

By changing or modifying the TX and RX sections and making a new coil, you would swear the Bandido was a different machine.

-C

[CHICKEN-WING]

BANDIDO

What would you charge if I sent you my Bandido to have this work done.

[Magman116]

Bandito

Do you have any mods for making my micro Bandito better I'd be very interested. I take it your talking about the older Bandito's.

We have thought about submitting a modified schematic for the Bandito, but then decided it was much better to completely redo the schematics for a complete mod.

For one, we would change the TX oscillator so to have a driven coil, then the demods would be changed to analog demods, the RX preamp would be changed for greater sensitivity and lower noise.

The best mod someone could do to the tesoro detectors is to construct a new coil with much lower inductance, and a higher "Q" factor. The greatest gains in depth come from the coil and TX oscillator. Most people have problems building coils and this is easy to understand. Coils can be built as hot as you like within reason, and as long as it is tuned or matched to the detector.

Also, you will want to place the TX tank circuit cap in the coil, and use only high quality metalized polypropylene capacitors.

I'll write more later.

-MM

[Turtle]

Do you have any mods for making my micro Bandito better I'd be very interested. I take it your talking about the older Bandito's.

[Magman116]

PCBs

As for the performance, with a properly built HOT 8" coil, it will detect a dime at depths greater than 15". Results will vary. If the coil is built to the included specifications, you could expect something between 14 and 23 inches for a dime. Also, this circuit would run off of two 9V batteries and give between 12 and 18 hours run time.

Initially we can supply the PCBs, Schematics, parts list, and assembly instructions for the PCB as well as instructions for constructing an 8" coil.

If there is not much interest, we will not get the PCBs manufactured for distribution. So, right now we are just seeing if there is enough interest.


-Magman116

[driscoll]

Yes i am