For all you tech heads. I have noticed that the Infinium LS has 96 frequencies, the Explorer SE pro has 28 frequencies and the DFX has 2 frequencies. Does more frequencies mean a better detector? Please keep your answer in simple terms.
TECH question regarding number of frequencies
- Thread starter Perry
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foreverRich
Forum Supporter
In simple terms, yes. Different metals are detected better at certain frequencies. That's why many companies who make single frequency detectors sell coils that operate at different frequencies. Multiple frequency detectors cost more to manufacture, but have a wider range of sensitivity to all types of targets. Hope this explanation is easy to understand.
Beefcake
Elite Member
The DFX runs on 3khz and 15khz frequencies or both simultaneously... I've heard that the SE is better... but I'm biased toward my DFX...lol Both machines are really good! I could be wrong, but I thought the DFX has more programmable capabilities... not sure about the SE. Others can offer more... DFXgreg I believe owns both.
Rudy
Admin
Perry,
Don't fall for all the marketing hype. How many frequencies a detector transmits simultaneously is not at all important. What is important is how many frequencies it simultaneously listens to. Frequencies that are transmitted but not listened to are a waste of battery energy.
Beefcake
Elite Member
post the question in "All about detectors" and someone should be able to answer it... or go to the link at that top of some of the pages at metaldetectorreviews.net it's a sister site to here and is very helpful..
West Texas John
Forum Supporter
The Infinium is a pulse induction instrument operating in the time domain. The Explorer is not a pulse induction instrument but is in the time domain. The DFX is a VLF that is operating in the frequency domain. They are all good instruments but I like the Explorer because it outputs so much data to the user which is very useful and helps me a great deal. The Explorer SE is the one I use most all the time.
John Tomlinson,CET
John Tomlinson,CET
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Rudy
Admin
The DFX "listens" on three channels. The High & low frequency channels mentioned previously, plus a "DC" channel, otherwise known as all-metal and is used in mixed mode.
I am not sure how many channels the Explorer listens to. All they ever talk about in their literature is the BS about Full Spectrum blah blah. But if you look at some of the Minelab patents, it looks like three channels at most.
The ML circuitry is somewhat unique in that the channels are not always on, but are gated on, in quadrature with the instantaneously transmitted frequency. That is why some people say the Explorer is a "time domain" machine. This is not quite true in the sense that it doesn't work at all like a PI detector does. PI's are the only true "time domain" machines. I've always wondered if the gating on-off of the receive channels contributes to the slow sweep requirements of an Explorer. I don't know for sure because little technical documentation is available.
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Rudy sums it up but you also have to consider that you pay a price for those Minelab frequencies (that in fact you don't have)....
Slow sweep speed. Slow = less ground covered.
You can have a single frequency machine with a coil tuned to the frequency that will go as deep or deeper as a multfrequency detector which is why Minelab were forced to withdraw their adverts with the arrows (single frequency arrow went a fraction down the page on the ads, twin went a little bit more and multi went deep).
Frequencies don't mean good discrimination either though there is the advantage that you have the ability to avoid interference by excluding a frequency. All P.I.'s have 90 plus frequencies and none, even the new TDI have true discrimination.
A further consideration is that they still don't produce a true lightweight twin or multifrequency machine. If weight is a problem and you don't want to be hung in bungy cord its better to look elsewhere. If you could get 12 inches depth with the Explorer and detect half a small field in a day you would be better off with a 10-11 inch depth machine that would allow you to search the whole field.
Slow sweep speed. Slow = less ground covered.
You can have a single frequency machine with a coil tuned to the frequency that will go as deep or deeper as a multfrequency detector which is why Minelab were forced to withdraw their adverts with the arrows (single frequency arrow went a fraction down the page on the ads, twin went a little bit more and multi went deep).
Frequencies don't mean good discrimination either though there is the advantage that you have the ability to avoid interference by excluding a frequency. All P.I.'s have 90 plus frequencies and none, even the new TDI have true discrimination.
A further consideration is that they still don't produce a true lightweight twin or multifrequency machine. If weight is a problem and you don't want to be hung in bungy cord its better to look elsewhere. If you could get 12 inches depth with the Explorer and detect half a small field in a day you would be better off with a 10-11 inch depth machine that would allow you to search the whole field.
Cherry Picker
Forum Supporter
Even a single frequency detector produces harmonics that can be advertised as a "multi-frequency" detector. As has been said, whats important is what the receiver does with those frequencies. The SE's patent(patent 5537041 section 9, lines 57 to 60) specifically says it does not use multiple frequencies.
Technically, the higher the frequency the better a detector is for small low conductive metals such as gold. The lower the frequency, the better a detector is able to penetrate the ground, and is more responsive to high conductive metals such as silver. My experience has been that the SE is a little more sensitive to deep silver, while the DFX is a little more sensitive to small gold targets.
Technically, the higher the frequency the better a detector is for small low conductive metals such as gold. The lower the frequency, the better a detector is able to penetrate the ground, and is more responsive to high conductive metals such as silver. My experience has been that the SE is a little more sensitive to deep silver, while the DFX is a little more sensitive to small gold targets.
The general rule was
High frequencies for small/lower conductivity items and low frequencies for larger, higher conductivity items.
Then miss out 20-24 KHz to avoid U.S. and European military interference.
However this has gone out the window in the last few years with the latest designs and no longer has to apply.
High frequencies for small/lower conductivity items and low frequencies for larger, higher conductivity items.
Then miss out 20-24 KHz to avoid U.S. and European military interference.
However this has gone out the window in the last few years with the latest designs and no longer has to apply.
Rudy
Admin
Detector, I searched the US and Australian patent offices for a patent with the number you included. No luck finding it. Can you PM me a link to where you found that patent? Thanks.
Ed in KC
Forum Supporter
Here's a link:
http://www.google.com/patents/pdf/D...ut=pdf&sig=ACfU3U1zbHTAis1Fzd_Ioua6kDVZTFhdvQ
Here's the section you're referring to, but I don't see anything about single frequency? It looks to me like it's a pulse wave with different lengths.
http://www.google.com/patents/pdf/D...ut=pdf&sig=ACfU3U1zbHTAis1Fzd_Ioua6kDVZTFhdvQ
Here's the section you're referring to, but I don't see anything about single frequency? It looks to me like it's a pulse wave with different lengths.
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Rudy
Admin
Thanks Ed.
There are two ways to view that pulse wave you refer to. One is in the time domain, which is what you "see" with a scope and would look just like you described. The other way to view it is in the frequency domain. It would look like a series of sinusoidal frequencies of different amplitudes, that sum up to produce that pulse train. This is what you would see if you used a spectrum analyzer instead of a scope.
For more info (if you care), google "Fourier series".
Ed in KC
Forum Supporter
I actually studied Fourier series back in the 70s in electronics school--not to say I remember much about it now though. What I don't understand is, why does the coil have to be moved if a pulse is used, because it seems like the detector would pick up the decaying magnetic field in between the pulses regardless of coil movement? Someday, I'm going to read up on this.
Rudy
Admin
Ahh, because VLF discrimination circuits usually incorporate some filter circuits. That is why in discriminate mode you have to keep the coil moving, whereas in All-metal mode, there is usually no filtration. That's why you often hear it being referred to as "All-metal non-motion mode". Some lower end detectors don't have this mode and instead have an "All-metal motion-mode", which is really a discrimination mode with zero discrimination.
Ed in KC
Forum Supporter
I see, that's why a PI detector doesn't have discrimination then. Thanks!
Boy, do we have some smart fellers here or what!!??!
