Anyone OWN an Ace 250 and understand electronics?

[candcantiques]

I learned a little bit about electronics when I was a kid and took a couple introductory classes in college. If a person increases DC voltage to a magnetic coil the magnetic field becomes larger. Does anyone believe that it would be possible to increase the voltage on an Ace 250 from the present 6 volts DC to 9 volts DC WITHOUT damaging the components? Most electronic devices, resistors, capacitors, IC's are designed to handle 12 volts but I am not sure about the digital screen. Any ideas or advise?

 

[cc8137]

Without the schematics available, I do not believe it would make much of a difference. First of all, the 6 volts is not direct current but a 6 volt, 6.5 KHZ audio signal. I'm sure design engineers experimented with different amplitude levels and settle with the 6 volts. (could be the max the FCC would allow without causing interference from other devices). I'm sure there are other factors such as ground attenuation, etc Anyway, I wouldn't try, not worth the effort.

 

[Alan Applegate]

I wouldn't even try! I don't have a full schematic of the Ace (just the parts listed in the patent). However, I can safely say you don't want to "boost" the voltage. The 6 volt input is regulated (as it is in every detector), and about all you would do is overload the regulator. The question still remains, can you boost the coil's field strength, and thus increase its depth? The simple answer is, no!

The long answer gets rather complicated. You can increase the size of the coil, and gain some depth. However, doubling the size of the coil doesn't double the depth. You can double the power applied, but that too doesn't double the depth. In fact, doing either only marginally increases depth. The ratio isn't exactly logarithmic, but it's darn close. Here's an example. To just perceive an increase in loudness from your stereo, takes an increase of 3 dB, which is double the power applied!

There is another aspect too, and that's the receiver. Once a certain input threshold is passed, receiver stability gets difficult to maintain. Using the stereo analogy again, if you crank up the power high enough, the speakers get to the point they can't handle the power applied, and they distort. This says nothing about the power amplifier's ability to handle the increase too, thus adding its own distortion products.

The bottom line is, you're looking for a low-cost solution, and there isn't one.

Alan Applegate, K

 

[Alan Applegate]

I don't know if this is the correct thread, but it is as good as any.

I haven't belonged to this forum all that long . However, there seems to be a lot of misunderstanding about how detectors actually work. Or don't work, as the case may be. One misunderstanding, it about the FCC Part 15.

Part 15 covers incidental RF radiators. These include the computers inside metal detectors, and their leakage to the outside world, if any. Most operate in the 3 to 10 MHz range, and that is considered RF which does fall under Part 15. What it doesn't cover, is the amount of power supplied to the coil, as long as there isn't the aforementioned leakage. For all practical purposes, the frequency range the coils operate in, falls within the audio spectrum (less than one MHz), and Part 15 doesn't include the audio spectrum. So that argument is moot, unless there is RF leakage.

Doubling power, or doubling the coil size, doesn't double depth. The field around the coil consists of electromagnetic waves. Although they act differently in air, the same basic rules apply to their propagation in any media, including earth. Using the stereo analogy again... If you're in your car, and the window is down, and there is a lot of outside noise, in order to hear your stereo, you crank up the volume. You might still miss the nuances of Dvoř

 

[candcantiques]

Well I guess that answers my question. I am not necessarily looking for a cheap easy way to get a better detector ( although if it can be found I don't believe its a bad thing) the most important thing to me is that I learn a little at a time about what can be done and what cannot. As I said I only know a little about electronics so I cannot say that I FULLY understood everything but I deffinetly understood enough to know now that increasing voltage will probably only cause problems if not ruin my detector. For that I thank all of you. Please be patient with my questions as a person can only learn by asking questions that may seem to some to be elementary. Thanks again.

I will probably just go get the excellerator coil next week.

For those of you that did answer. I would ask this. I have a Whites coinmaster classic 3, not the plus. Someone upgraded the machine with a blue max deep scan 950 8" coil. I am told it will cause problems but it seems as if it works great as long as I do not use the black sand setting. Is it possible for someone to have upgraded the electronics inside as to aleviate the problems that everyone thinks this machine should be having? I am getting ready to take it to the beach in the morning and bury gold in the wet and test my ace with the stock coil against the whites in normal mode and see which detects the deepest. I will let everyone know what happens then maybe we can discuss upgrades more. Again thank you all.

 

[Canman]

This might help

 

[candcantiques]

It has been so long since I have done anything with electronics I would have to relearn alot in order to understand the basics of what I was seeing. The last of 2 basic classes that I took was in 1985 and I have done NOTHING with electronics since except maybe a little soldering here and there (which in my mind doesn't count hahahaha) I do sincerely appreciate it though and I understand most of what was said in the above posts. I now understand that my best bet for now is to upgrade to the excellerator coil then move up to an 800 or a 1000 ( minelab ). Wish me luck, Bike week is now in full swing and I am headed out in the morning before sunrise to hopefully find what is being lost right now. The next 30 days are going to be 6-8 hour days on the beach Mon - Fri and Sat and Sun evenings. Bike week, Spring break then BCR (black college reunion). If anyone has any advice for settings in wet sand for an ace 250 with the excellerator coil I would be eternally gratefull. All proceeds go towards an Excalibur 800 or 1000 unless there is some better advice. Thanks all

 

[metalhead]

You know what this reminds me of? Remember when Garrett(and others) began using those 2 four pack AA battery holders for the machines with 8 AA batteries(which are still in wide use today and work great)? Previously, most detectors all used the 9V batts. I guess this was back in the early nineties as I recall. Anyway, a bunch of guys tried using 9V batts instead of AA. Like four 9V instead of 8 AA to give their machines a little more oomph? And it wound up frying their machines and of course the manufacturer would not cover repair under warranty.

Oh, hey, candcantiques, you're gonna love that 10"x14" Excellerator search coil on the Ace. I hope you're able to get that Excal that you want soon. Best of luck to ya with that Happy Hunting!

 

[Alan Applegate]

Here's a comparison for you.

I have a fairly new Ace 250, and an older one I bought from an estate sale. They both work, and for the most part, exactly alike. However, there is a subtle difference that you wouldn't notice unless you owned two. I suspect part of the issue is the variances in components. I did purchased an Excelerator coil, and it does work better in that it is less prone to soil changes. The question remains, does it go deeper? In my opinion, every so slightly, but it's nothing to write home about. I suspect is non-mineralized soil, the difference between it and the 9x12, is all but moot.

Comparing the Ace with the Excelerator coil, and the GTI-2500 with the 12.5 inch coil, it isn't even a contest! In my salted garden, one of the quarters is 6 inches down. Sometimes you hear it on the Ace, sometimes you don't. It just depends on which direction you scan. Sometimes it tells you it's a quarter, sometimes a dime, and the depth is only approximate. The 2500 finds it easily, correctly IDs it, and the depth is very close.

There is a small Chondrite about 1 inch across, down about 10 inches. The Ace can't find it. The 2500 will find it, but tells me it's a screw cap at 8 inches.

Again, the most important part, is the filter between your ears!

Alan Applegate

 

[SteveP(NH)]

As I understand it the response from the ground is many times greater than the response from potential targets and as you increase output power the response from the ground gets stronger faster than the response from targets and so your signal to noise ratio gets worse.

Metal detector designers and engineers carefully calibrate output power to achieve the best signal to noise ratio and depth. Changing what they have chosen for a particular design will likely result in worse results than the detector operating at its default levels.

 

[candcantiques]

The GTI-2500 sounds like a great machine however for the beach, if I was going to spend $600-$900.00 I am going to spend it on a Minelab Excaliber 1000. Not trying to dis Garrett in any way however while I have read that it can be tough to learn the excalibur, everything I can find tells me its the best for beaches and underwater.