what is kHz???

[littlenugget]

i am new at metal detecting , waiting for my scorp a few weeks ago, its not here yet, iam just wondering what does khz mean i have seen that many detectors have 8, 15, etc......what is khz ..

if a have less khz, that means that i would find more gold??? and more depth????

 

[John-Edmonton]

Frequencies in a metal detector are referred to in kHz (kilo hertz) which is the number of times a signal is transmitted into the ground as received back per second. The lower the detector's frequency, the deeper it will penetrate. However, its sensitivity to smaller targets may be reduced. On the other hand, the higher the detector's frequency, the higher its sensitivity to even the smallest targets, but it may not penetrate as deeply.

Generally, gold detectors operate at a higher frequency for locating small gold nuggets. Coin, relic and treasure hunting detectors operate at lower frequencies for greater depth penetration.

 

[Muddyshoes]

That makes sense. Then how do the various settings for "depth" or "sensitivity" work? What is happening when you make changes to those settings? And for those detectors where you can change the frequency, what does that do exactly?

 

[Lightstryder]

That makes sense. Then how do the various settings for "depth" or "sensitivity" work? What is happening when you make changes to those settings? And for those detectors where you can change the frequency, what does that do exactly?

I believe you are changing the amount of power input to the field transmitted from the the coil. I am no engineer, but I believe that is a close explanation. Imagine a dimmer switch for a light in your house.

 

[Jerry-Wi]

It is a unit of measurement. Years ago we used to say Cycles Per Second on referring to frequency of alternating voltages. I think in the 1960's it was changed to Hertz to honor Heinrich Rudolf Hertz. You can read more about him at http://en.wikipedia.org/wiki/Heinrich_Hertz. The K in front represent thousands. If it was and M it would represent millions. 14.5 Khz means 14,500 cycles per second. 14.5 Mhz means 14,500,000 cycles per second. Metal detectors will have slightly different characteristics as the frequency is changed and manufacturers will use that to their advantage depending on what type of detector they are building.

Jerry

 

[NM5K]

I haven't talked to Garrett, but I think with most of the modern
machines, the power into the ground remains constant. The
sensitivity is just that, the sensitivity of the receiver, same as a
shortwave radio.
This is why I often run pretty hot. With my machine, you need to
run fairly hot in order to have the sensitivity to detect the whole
pattern that is radiated into the ground. If I run half way, I'm stunting
my machine. It's not sensitive enough to receive the lowest depths
of it's fixed power into the ground.
Of course, falsing can be an issue running like that. That's why
I say to let the ground tell you how high to set it. If it's squawking,
turn it back a bit. But some grounds, I can run full blast with only
minimal falsing. If I can, I do. You do get more depth performance
than if you had it halfway over that "quiet" ground.

The use of frequency with detectors is the same as with a radio.
Detectors being on the low end of the RF spectrum. I think my 250
is 6.5 kc if I remember right. In comparison, aircraft NDB beacons
are up in the 200-300 kc range. 540 kc is the beginning of the low
end of the AM broadcast band.. Just to kind of put it into perspective
with the rest of the RF spectrum. The spectrum classifications go by
"3's" IE:, 3, 30,300,3000, and so on.. IE: HF is 3 to 30 mhz, which is
the same as 3000 to 30,000 khz.. 1000 cycles = 1 khz. 1000 khz = 1 mhz,
and so on.. Detectors are in the 3-30 khz spectrum, which I think should
be the VLF, or very low frequency spectrum. 30-300 khz is LF.. 300-3000 khz
is MF, or MW as some call it.. And so on.. :/
Sound is generally considered 20-20,000 cycles.. Some can likely hear
better than that when young. The high end falls off as one ages.