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Equinox Is Multi Frequency? Or Isn't It? Is It Not? It Is! Isn't It?

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Deep in the depths of winter here, I found myself partaking in some serious speculating.

With all the controversy of whether or not the Equinox is multi frequency or not, I figure I'd bring some wood to keep warm lol.

Some of you may recall in one of those threads I was trying to explain that the waveform we see can actually be comprised of more then one, two, three or more frequencies. Additionally I pondered if the multi frequency processing could just be done on the receive side using typical sinusoidal waves that are actually doing the work. Nonetheless here is the transmit side, the side that actually excites the target.

Below you will see a FFT (Fast Fourier Transform) of the Equinox in Gold2. The scale goes from DC to 125 kHz. (Left to right)

If you consider the advertised range of Multi-IQ frequencies as being 5 kHz to 40 kHz, you might be satisfied by this as the left half of this 125kHz graph is filled out nicely. There is even a couple little peaks up around 100 kHz, whether or not that is utilized I don't know.

I'm way off base as to how MIneslab actually does this, but I just wanted to show the kind of information that can be extracted from these signals. I am not trying to prove anything specific other then to say I don't think Minelab is being misleading IMO. Assume something is a little off with my measuring, still that looks like multi-something.

The approximate frequency peaks of interest measured from left to right are:

-2.5 kHz

-8 kHz

-13 kHz

-18 kHz

-23.5 kHz

-28.5 kHz

-33.5 kHz

-39 kHz

-44 kHz

-50 kHz

-54 kHz

-59.5 kHz

That covers the advertised range of frequencies which exist on the left hand side of the graph, (Midpoint is 62.5 kHz) I wont bother with the higher frequency stuff as it may not be relevant.

It doesn't really hit any of the single frequencies, on the other hand Minelab does not explicitly say what frequencies are used in Multi-IQ. (That I know of.) I am happy to see that low frequency response. I was thinking the Equinox was going to be all 8 kHz and higher, which it basically is, but I'm glad to see the 2.5 kHz peak right beside it and of almost equal strength.

Equinox FFT.jpg

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I too have saw the 2.5 kHz show up on the multi-frequency scans I've done.

I too am 100% satisfied with my Equinox.

Hats off to Minelab, another winner in my book.



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19 minutes ago, Mark Gillespie said:

I too have saw the 2.5 kHz show up on the multi-frequency scans I've done.

I too am 100% satisfied with my Equinox.

Hats off to Minelab, another winner in my book.



I went back and found those posts by EL Nino, his results have the same peaks as mine. I was looking for yours as well, maybe you didn't post them. That's alright either way.

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Equinox .. : Patent :US7432715 , US7579839....Minelab says in the patent that Tx emits from 2.5kHz-80khz - but the RX side receives frequencies from 5khz to 40khz and all over 40khz is filtered ...

A few days ago I made measurements and compared all Equinox programs on Old 1.5.0 and New 1.7.5. Firmware, So soon to publish it ...I have also scanned the frequency of 5,10,15,20,40kHz ....

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11 hours ago, EL NINO77 said:

Equinox .. : Patent :US7432715 , US7579839....Minelab says in the patent that Tx emits from 2.5kHz-80khz - but the RX side receives frequencies from 5khz to 40khz and all over 40khz is filtered ...

A few days ago I made measurements and compared all Equinox programs on Old 1.5.0 and New 1.7.5. Firmware, So soon to publish it ...I have also scanned the frequency of 5,10,15,20,40kHz ....

I have been reading those patents over, they are very interesting. I'll admit the first one is pretty long, I forget what I am reading after a while, just mouthing the words like I'm back in  school. lol

The patents are more specific and fortified due to the nature of the documents compared to the ads we see from the marketing department. Dumbed up vs dumbed down? lol

It's starting to become a little more understandable.

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As El NINO mentioned the Equinox transmits up to 80 kHz I thought I would try and get a better measurement to see the higher frequencies a little better. Again my measurement might have put a slant on the result as I doubt the coil I used to test with would give a flat response over such a wide range.

I also included a picture of the ~2.5 kHz "square" wave or whatever you want to call it.





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I made measurements of EquinoX 800 on old 1.5.0 and new firmware 1.7.5: 

Park1: 1.5.0 


Park1 : 1.7.5


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Park2: 1.5.0


Park2: 1.7.5


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Field1: 1.5.0


Field1: 1.7.5


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