Manual ground balance mod. for Lobo ST?

[Chuck from Michigan]

Can it be done? Is it worth it?
Thanks in advance,
Chuck

[Siliquae_Sid]

Yes and....NO!

The Lobo CONTINUOUSLY tracks the ground using a microprocessor to adjust a digital potentiometer instead of you having to tweak a potentiometer. Very primitive, but VERY effective.

Sorry to sound cynical, but why would you want to set the control once and then have it be inaccurate for the rest of the session, when a micro can do it for you? OK you might want to set an offset for greater sensitivity to small objects. I suppose that could be done. But the offset would have to be added AFTER the point in the circuit which the micro uses to take its reference, otherwise the micro would just null out your offset too.

Get me the diagrams and I'll design the mod for you.

[Chuck from Michigan]

Thanks for the ideas Sid.........But

I am not up on the technical aspects and basically when a company said it has a computer that does the work for me I just wonder if its a sale gimick.

So, are you saying that a manually adjusted ground balance on the ST would not help?

I hunt for jewelry in the water. Any other ideas?

Regards,
Chuck

[Siliquae_Sid]

The Lobo SUPERTRAQ has a computerised ground balance, hence the name ....It "Traqs" the ground.

The LOBO NON ST is a manual system and would probably be better for what you require.

Hope this helps.

For once, it's NOT a sales gimmick

[Markus]

Hello,


the Lobo-St has two ground controls.

One is the microcontroller unit with the two digital pots, which is only working in the allmetall mode, but there it is the best automatic ground i've ever seen.

The disc mode has a simple fixed ground (adjusted to ferrite) with R33, but if you are shifting the ground you are also shifting the complete disc range, it is not forseen to use it in the field.

HH
Markus

[Siliquae_Sid]

Hi Markus,

Do you have more info your could give me please? I get a lot of people asking if I can put an offset on the ground tracking system of the LoboST, but I have no idea which trimmers to "twiddle" Any help (even a schematic) would be GREATLY appreciated.

Whites have the best ground track system bar NONE, you can set user defined offsets, and unlike the LoboST it doesnt try to null out all metala targets AND it works in disc mode too.

I agree with you on your point that you shift the disc range. This is true on any machine which has the GEB control BEFORE the synch demods, just like the DeLeon and Cortes do. THis means that when you change heads and recalibrate the ground balance, the Target ID meter goes to pot! Nice primitive systems from Tesoro, but then I'd expect it from them.

I spent a week designing a systeme which would track the ground and NOT affect the discriminate range. I succeeded and I'm incorporating it into the machine I'm designing.

We can swap ideas privately if you like, it's always interesting to share theories and designs with people.

Cheers

[bdoubled]

Hi Sid,

I own a Tesoro Cortes and have always wondered why auto GB was not designed into it. Is the ground tracking mod you have designed adaptable to the Cortes? If so, it certainly will help improve the Cortes' performance and versatility.

Regards,
Bill

[Sean Goddard]

Yes it would, BUT, Tesoro have used a very primiteve design for the Cortes (it's basically a Silver Sabre plus with a TID meter and a bit of a boot on the output.

Because you need a fixed reference on the GEB whene doing a TID system. Tesoro fixed the phase angle between the Ground and the "Disc" channele to 90 degrees to enable them to demodulate the required phasor signal. They COULD have had the user take a reference by lifting the head then tracking the changes when it was lowred to the ground, but no, it was too hard for them ;-{.

They opted for a simple fiexd ethod becasue IF you change the GEB phase sample point, the target readings go off. This is why you get SO many Cortes and DeLeons with innacurate TID meters after the search head has been changed.

I designed a system which meant you CAN adjust theground balance in A/M and Disc and your TID meter remains accurate. This system is incorporated into my metal detector designs due on the market soon.