Can you boost KHZ? theres gotta be a way..

[myk3916]

Hi im mike, first post..

Been into prospecting for a few months, i know - i know nothing, but i really want to tinker... I know detectors run on sensitive frequencies i understand, and if you did modify anything you would still be limited by hardware capability (for example a 7.5 khz coil wont run at 18 khz, no matter how hard you try)

But if you were able to solder, snip and add a mod board, and run wires to jump the board to the equipment, could frequencies be boosted?

I want to buy a starter detector (ace 250) to learn, but have been told not to waste time or money and get a garrett at gold... But if i can boost the ace, i would get it for beggining... I want to get it also, so i dont spend a lot on a nice one and break it before i know what im doing..

Two examples: (a cb radio example, ive done this before)

http://www.cbtricks.com/radios/cobra...en_Var_Pwr.pdf

http://www.cbtricks.com/miscellaneou...od.jpg

Now ive seen all kinds of mods, and heard of people running 224khz, even heard of 1.5mhz detectors, and learned that thoose walk thru detectors in court houses run at 8.4mhz...

Im really interested in this for a beggining project (my first project) if possible, i just dont have enough info...

Can anyone help? Ideas?

[Carl-NC]

For the most part, changing the operating frequency of a detector is not easy. Most of them are driven and controlled by a micro so you would need to reprogram the micro. Also, most coils are not flexible enough to deal with big changes.

BTW, walk-throughs are usually very low, perhaps 1000-3000 Hz.

[Silver Dollar]

Changing the frequency is not the usual method to improve a metal detector.
Sensitivity and signal to noise is much more important as you are looking for
a microvolt signal in the present of millivolt noise. The coil has a big influence
on sensitivity that's why you see expensive aftermarket ones for sale. So I'd
buy the detector and upgrade the coil if you find the need to. Most people
eventually learn to find the targets by using their detector better as they
work with it over time...

[golfnut]

That said Ive retuned a 250 which runs at 16kHz. Unfinshed project for now but with a little grit you can pull it off. You can also add small pot for ground balance too

[sinclairuser]

the problem here is you are making a usual misconception, metal detectors are not radios, it just does not work that way.
first thing i would suggest is to buy and read inside the metal detector, but before this forget every thing you know about radio it will lead you up the garden path, also dont buy a md just to butcher it thats daft.
if you need a gold detector buy a gold detector, and dont void the warranty thats where madness begins, nearly all detectors have specific uses, buying the wrong machine and trying to make it into the right machine just does not make sense.

[myk3916]

That said Ive retuned a 250 which runs at 16kHz. Unfinshed project for now but with a little grit you can pull it off. You can also add small pot for ground balance too

And how is this possible? If true i will buy one, use it for a while then mod it, until i get better to buy my "at gold"...

Please share!?

[myk3916]

I appreciate all the comments but I refuse to believe that technology cannot be upgraded...

If you look at any computer, its an upgrade of the original 086 architecture... Yes upgraded components and hardware as well too... Evolution of the computer shows that microprocessors get smaller and faster...

Point being, all computers are run by an i/o system written in assembly language, then a runtime module loads pre compiled data as a interperter... Thus Ms windows is an upgrade of an upgrade of another upgrade and so on...

Now older architecture cannot run todays software because of limitations, but we can take newer technology and emulate it on these older systems...

(You are probly asking what the hell this has to do with detecting about 2 minutes ago...)

Yet i understand these limitations as compared to detecting, i just dont know a lot about detecting yet and computers are something i do understand, so thus i can try to explain with something i do know.

I was hoping there could be a way... I guess i will have to read a ton more til i get detector understanding...

I was really interested when i seen the newer style metal detectors that have 400 & 600 etc mhz microprocessor circutry.

Now i would like to propose this, could we build a usb serial r232 interface or a bluetooth protocol to connect to per-say a laptop and connect our detectors to the laptop Thru this interface? This i understand would require software to interpret, but i believe this could prove to be a huge tool in detecting... Ask me why? Im just a gadget and gizmo kind of guy i guess...

and i think terain mapping thru a pc could prove useful... Of coarse that would require somekind of gps, but that is easy...

[Carl-NC]

As an example of your analogy, try taking a PC/XT and upgrade it to a Windows 7 system. You will end up buying more than the equivalence of a new computer. It is generally not at all simple to convert a given detector into a new type of detector. It can be done, but you really have to know a lot about what you are doing. Your other ideas have been discussed here over the years, you might be able to dig them out with the search feature.

- Carl

[Silver Dollar]

Many detectors do not had a microprocessor and the ones that do usually have locked software so you can't
see the code. That makes it difficult to "Tweak" it. Adding a lot of digital components can contribute to the
noise so make for worst performance. A better idea is to start with your own or another's open design then
make it do what you want. That's what this site is all about. I've got an idea brewing for an addon to the
Hammerhead to make target ID work better. It uses only one chip (a DSPIC) and will rely heavily on software
(that I have to write) to do it's magic...

[myk3916]

yeah I think software control would be a really big advantage... not only would we be about detecting but also surveying...

[myk3916]

I guess the answer for modification purposes has some What been answered here I appreciate your comments because everyone else that I talked to said it was impossible..

I guess you're telling me it is possible but very hard or right next to impossible... which is an upgrade from impossible I would guess...

how about pinpointers? I know pinpoint have a higher frequency is there anyway you can modify a pin pointer to use a basIc coil and just use the guts/board?

Now with this idea depth usually goes by the radius or diameter of the coil.. Would trying to change a pointer to a coil require extra extra modification?

[myk3916]

I re-read what i wrote, and came to a 50/50 logical conclusion..

pinpointers have higher khz function, could i take the guts of a pinpointer and take a 250, cut and splice them together, but run the pinpointer as an upgraded addon board?

this sounds complicated to explain but i think you get my gist.... actually somewhat suprised myself with that one....

[Skippy]

While your enthusiasm is a good thing, PLEASE start at the beginning, with simpler, less, ahem "experimental" ideas. The easiest bit of an ACE250 to re-use is the shaft hardware. Why not, for fun, build a "Surf PI" and make it fit the Ace's shaft, they can easily be swapped back and forth (2 screws, I think)Even making a new searchcoil for the ACE is an imposing task, but people say the larger aftermarket DD coils that are available work well on it, so there's an ambitious project for you.

[Silver Dollar]

What is your preoccupation with higher frequencies? Do you want to find tiny bits of gold?
The Golden Sabre thread here can show you how to change frequency somewhat. The problem
is ground balance and discrimination can be thrown off if the new phase relationship between
TX and RX is not similar to what you started with.

In my reading I found that 12.5 khz is a good all around frequency. A multifrequency unit can
determine more info about the target and some targets will respond better at a particular frequency.

[myk3916]

the sensitivity to smaller objects is what I am looking for... discrimination is not a really big deal...

I was playing around with a shop owner that had a Garrett XT, that machine will find anything and everything... I believe 44-48 khz... but it was also hitting on a lot of false positives... Sweet machine no doubt... even trying to run the auto calibration was tricky...

I'm not looking for anything that powerful to start, but I would like to run around 20 Khz to start off as a beginner...

you know I did look up all those kits... but none of them have specifications, and then I determined that I guess it depends on how well you build it.

I think I am going to tinker with the 250 anyways, and maybe surprise a couple people here if I can manage that... a lot of people of told me that there are things that I would never be able to do and they were very simple to me... but then again I have failed many times... only 1 way to find out right?

give me a little over 30 days and I will try to post my results in the same catagory, new thread, different topic... I guess I will order the 250 and start a New thread and see if anyone can help me along the way