Frequency question

Different frequency question? Excluding the multiple frequency machines that Minelabs makes.

Has anyone tested different frequencies in a test garden? And if someone has, what were the results?

From reading different forums it seems  that with today's technology there is no difference in depth between a 14 kHz and a 3 kHz machine, unlike the past where the lower frequency would be more sensitive and deeper on high conductive metals vs high frequency being more sensitive with low conductive metals. Is this a correct understanding?

Is there a proven demo?

Seems that way....but then again might have to dial in ones mineralization...to me the CZ with 5 and 15 was that way to cover both sides f the spectrum....

That is correct. Higher freq units are now acquiring the depths that only the lower freq units could......... once........... long ago........ acquire.
I think I reported Freq vs Depth on the XP Deus Field Test thread.

That's a good question, with lots of complicated answers.
Firstly, it's worth pointing out that you would need to perform your different frequency tests with essentially the same machine. And that narrows down the choice massively. You could, say compare the XP GMP (18KHz) with the GMAXX2 (4.7KHz), they're both the same machine, really. But.... the GMP was introduced first, the GMAXX2 is a tweaked version, using the existing Adventis/ADX250 coil. So have design compromises been made to produce the low-freq machine?
Using an XP Deus and switching freqs might seem a good test, but again, the machine seems optimised for 12K or 18K, the two lower freqs don't seem to do anything 'special'.

And then there's the targets themselves. While a targets' "best detected" freq may vary over a huge range, there are some important practical limits. The metal a target is made of can't conduct electricity any better than copper or silver, and these metals are actually used in coins, and silver finger rings. So the only way to make a target have a lower freq is to make it bigger, eg. silver dollars / half-dollars. Bigger means easier to detect, so less need to optimise a machine for them. Choosing say 6 - 8KHz will be close enough to small-ish coin targets like dimes, and the fact that they aren't optimal freq-wise, for silver half-dollars is offset by the size of the big coin. But manufacturers know people want to find gold finger-rings, and cupro-nickel coins, which are quite common world-wide. So offering machines with a freq towards the 15 - 20KHz region of these targets, such as the F75 / T2 makes sense.

The ground signal the machine picks up varies with frequency, which is the other important factor. It get stronger as F increases, which tends to limit depth.

Regarding the "no difference in depth with todays machines", I think that lower freq machines are less sensitive to high-freq / low-conductivity targets, or they will call them iron. Whereas the higher freq machines can still find the low-freq targets.

Thank you for the replies. I ran my AKA through the 3 different frequencies over the same area and they all picked up the same signals, no difference. But It wasn't a true test.

And this allowed use of higher frequency while still retaining depth=in my eyes, depth and unmasking with same detector- especially on low conductors.

It appears that the newer technology is able to receive and respond to weaker signals that the target creates. If this is the case does that explain why EMI is more of an issue with higher frequency detectors?

Test a quarter against a nickel. Most of today's detectors are going to response better to the nickel than the quarter. That is frequency dependant. I could probably continue and say that most modern detectors today will respond better to the nickel than a half dollar.

HH
Mike

I have a 15 year old test garden. All coins and tabs are at 6 inches. Every machine I ever tested hits all coins well as to be expected. I can tell on most hiogher freq machines like the Silver Sabre, Compadre, m6, mxt,f19.f70,atpro.atgold I mean the list just goes on but say 12khz or above - They bang on my nickel and tabs a lot louder than my lower freq machines say under 7khz Like the Xlt, f2, classic idx, Prizm's (yes I tried it) I have dug deep nickels with my GBP and F19 but have also dug deep silver as well. I would just say that if your looking for jewelry you will most likely get a better sounding "hit" with a higher frequency machine and maybe loose minimal depth on high conductive targets with the new machines. Maybe no depth difference?