Number of frequencies

[pustareka]

Hi,
I have been looking at a detector that claims to be a 71 Frequency detector, that's 71 frequencies from 4khz to 18khz in 0.2khz steps, can you really have 71 selectable fundamental frequencies in a detector or is it a case of a few fundamentals and there harmonics?

Can a coil be tuned to all 71 with max sensitivity to all?

Most detectors are advertised as one or two frequencies with offsets.

Curious if this is just marketing getting carried away?

Thanks
Dan

Infinito № freq. CADUCEUS COIL !!




http://www.rexresearch.com/smith/caduceus3.htm

[ivconic]

It generates the frequency with a microprocessor, so it's possible to generate just about any frequency, 10Hz if you want. It then forces that frequency onto the coil, in a similar way to MineLab FBS/BBS/Multi-IQ, Whites DFX/V3.
...

Of course it can be done all within single MCU.
It is just me; always worried and stressed upon MCU resources...
BTW is it possible to know which MCU is used there?

[Carl-NC]

Is that the case with all coils as I thought for example you couldn't use a Whites DFX coil on a V3i.

Some coils are wideband, some are not. MF detectors use wideband coils, basically just an inductor. But even an inductor has self-capacitance that screws things up. Originally, the V3 was supposed to use stock DFX coils, but the stock DFX coil wasn't wideband enough to hit 22.5kHz. It had to be tweaked to work, hence "V-rated" coils, and those will still work on a DFX.

Even though it has 71 frequencies it's not classed as multi frequency though is it?

Marketing people will try their best to confuse the issue, but multifrequency means 2 or more at the same time.
I call the Alter 71 a variable frequency detector.
I call the Eureka/XTerra/Deus selectable frequency detectors.

[kt315]

this oldie ML eurika gold. has 3 frequencies. enough. 71 freqs is sure clear adwerts way for me.

[Qiaozhi]

Im not quite sure what any of that has to do with my original question? It appears you are implying I am trying to sell or promote something? Why I don't know.
For a newbie/novice you are talking in complete riddles.

As you're new here, you don't yet comprehend KT315.
You'll get there. Don't worry.

[Danno]

you asked to give info. ok. where is the schematic of this detector? without full data i am not able to answer you in full form you wait.
is it OK?

The manufacture probably has the schematic locked away, certainly not available to the public.

[Danno]

Carl said " it's how most multifrequency machines work" , meaning : forcing a waveform of your choice, at any frequency you want, onto a transmit coil. It doesn't matter if it's only a single frequency ( like the Alter71, or in fact the Fisher CZ-series ) or two (DFX ) or 3 (V3 ) or 4 ( Multi-IQ in 'beach mode') etc.

Thanks, got it

[kt315]

Im not quite sure what any of that has to do with my original question? It appears you are implying I am trying to sell or promote something? Why I don't know.
For a newbie/novice you are talking in complete riddles.

you asked to give info. ok. where is the schematic of this detector? without full data i am not able to answer you in full form you wait.
is it OK?

[Skippy]

Carl said " it's how most multifrequency machines work" , meaning : forcing a waveform of your choice, at any frequency you want, onto a transmit coil. It doesn't matter if it's only a single frequency ( like the Alter71, or in fact the Fisher CZ-series ) or two (DFX ) or 3 (V3 ) or 4 ( Multi-IQ in 'beach mode') etc.

[Andi68]

Yes, because only one work frequency is selected

What are you actually talking about?

[Danno]

The easy way to make a variable frequency detector is just drive the coil with a square wave voltage, and don't resonate with a cap. Then you can pick any frequency you want. Probably what the Alter 71 does. It's how most (all?) multifrequency designs work.

Even though it has 71 frequencies it's not classed as multi frequency though is it?

[Danno]

It generates the frequency with a microprocessor, so it's possible to generate just about any frequency, 10Hz if you want. It then forces that frequency onto the coil, in a similar way to MineLab FBS/BBS/Multi-IQ, Whites DFX/V3.
Quote:"Can a coil be tuned to all 71 with max sensitivity to all?"
It's not tuned to any of them, so hopefully works adequately over all the range.

Is that the case with all coils as I thought for example you couldn't use a Whites DFX coil on a V3i.

[Danno]

electrical tomography

http://zond-geo.com/english/zond-software/ert-and-ves/zondres2d/

http://zond-geo.com/english/zond-software/

http://www.avto-sib.ru/nemfis

Thanks but way over my head, especially the last one in a foreign language (to me)

[Danno]

Quasar ARM works with any frequency (max 21kHz), Krot works with any frequency, Fortune M works with any frequency. what is new in his detector? closed schematic?
covered HEX code? thats new? i reminder Quasar Krot and Fortune are free. you went in this forum adwertizing some commerzialized detector with no KITs,
no pcb for sell, nothing for DIY nuts. also i reminder you this forum is NOT INDEXED in google. all your activity here is absolutely unperspective bare if you want to sell this detector.

Im not quite sure what any of that has to do with my original question? It appears you are implying I am trying to sell or promote something? Why I don't know.
For a newbie/novice you are talking in complete riddles.

[pustareka]

Hi,
I have been looking at a detector that claims to be a 71 Frequency detector, that's 71 frequencies from 4khz to 18khz in 0.2khz steps, can you really have 71 selectable fundamental frequencies in a detector or is it a case of a few fundamentals and there harmonics?

Can a coil be tuned to all 71 with max sensitivity to all?

Most detectors are advertised as one or two frequencies with offsets.

Curious if this is just marketing getting carried away?

Thanks
Dan

electrical tomography

http://zond-geo.com/english/zond-software/ert-and-ves/zondres2d/

http://zond-geo.com/english/zond-software/

http://www.avto-sib.ru/nemfis