Minelab FBS System

[satdaveuk]

Hi fellow engineers
Can one or some of you answer me these questions please

1st... With the FBS system am I correct in thinking that although it transmits multifrequency it only analizes 3 frequency and if im correct do you know which actual frequencys they are?

2nd ..... Deus: Have I been told correctly that you can only detect one frequency at a time, because i find that very hard to beleve.

Thanks in advance

Dave

[mikebg]

Dave, at pulse induction each sample corresponds to a frequency. When sample delay increases, the frequency of sample decreases as shown below.

When we use for signal processing only one short sample, our PI operates as narrow band (CW or single frequency) metal detector. The drawback of this VLF metal detector is that TX is very inefficient, but we can easy change its operating frequency.

When we use for signal processing more samples, the PI operates as wide band metal detector. The maximal possible frequency is illustraded below.

[Qiaozhi]

Dave is not asking about pulse induction. He is asking about Minelab's FBS system ->
http://www.minelab.com/consumer/know...b-technologies

and the XP Deus ->
http://www.xpmetaldetectors.com/uk_detecteurs_DEUS.php

[satdaveuk]

Dave is not asking about pulse induction. He is asking about Minelab's FBS system ->
http://www.minelab.com/consumer/know...b-technologies

and the XP Deus ->
http://www.xpmetaldetectors.com/uk_detecteurs_DEUS.php

Hi Qiaozhi
Thanks for the urls but i already looked at these and neither of them answer my queries on top the page.
There must be someone on here thats knows if my information is correct or not.
And yes we are talking about induction balanced machines.
The tech page on the fbs system says its transmitting 1.5khz-100khz, but what it doesnt say is what is it doing with them, because im led to beleave that only 3-4 actually get analized to id the target at anyone time.
Far as the deus someone told me in another forum that you can only detect one frequency out of its choice of 5 at anyone time, im sure there wrong because even my dfx is capable of either using both at the same time or independent frequencys.
Hope someone here can clear this up.
Also thanks for trying to help Mike
Regards
Dave

[Qiaozhi]

Hi Qiaozhi
Thanks for the urls but i already looked at these and neither of them answer my queries on top the page.
There must be someone on here thats knows if my information is correct or not.
And yes we are talking about induction balanced machines.
The tech page on the fbs system says its transmitting 1.5khz-100khz, but what it doesnt say is what is it doing with them, because im led to beleave that only 3-4 actually get analized to id the target at anyone time.
Far as the deus someone told me in another forum that you can only detect one frequency out of its choice of 5 at anyone time, im sure there wrong because even my dfx is capable of either using both at the same time or independent frequencys.
Hope someone here can clear this up.
Also thanks for trying to help Mike
Regards
Dave

Hi Dave,

Actually I wasn't trying to answer your questions with the links. I was just explaining to MikeBG that you were not asking about pulse induction detection.
I'm not sure about the FBS system. I think it depends on the Minelab detector in question as to how many frequencies are analysed. Perhaps one of the Australian guys will know the answer.
Someone I met at a metal detecting rally, who was using a Deus, gave me the impression that you have to select the frequency you want to use. In fact, you can download the user manual from here ->
http://www.regton.com/deus.htm
which states the basic frequencies are 4, 8 12 or 18kHz. See page 11.
It appears that your source is correct.

[satdaveuk]

Hi Dave,

Actually I wasn't trying to answer your questions with the links. I was just explaining to MikeBG that you were not asking about pulse induction detection.
I'm not sure about the FBS system. I think it depends on the Minelab detector in question as to how many frequencies are analysed. Perhaps one of the Australian guys will know the answer.
Someone I met at a metal detecting rally, who was using a Deus, gave me the impression that you have to select the frequency you want to use. In fact, you can download the user manual from here ->
http://www.regton.com/deus.htm
which states the basic frequencies are 4, 8 12 or 18kHz. See page 11.
It appears that your source is correct.

Ok thanks for that so we have sorted that one out.
Now to the FBS system, I was thinking say either the Quattro which is a simlified version of the Etrac, and the Etrac itself, I would ask on the minlab owners forum but I want a unbiased technical answer to how it receives and processes the signals received because this subject does come up from time to time.
All the best
Dave

[Skippy]

Dave, the Deus runs at a single frequency, and that frequency can be selected electronically, rather that by, say, changing coils, as on Minelab's X-Terra machines. The search coil has a processor in it which controls relay contacts to switch in/out tuning capacitors and/or different coil taps, and also change drive frequency, I would imagine, as this is synthesised. I am told you can hear the relay click when the frequency is changed.Regards.