Looks like a round from a Browning 0.50 heavy machine gun to me.

Your unfired round has fallen from an aeroplane, probably WWII vintage, the casing may have a manufacture date-code, in addition to place of manufacture.
I have similarly found one, in woodland, pointy-end down ( and hence firing pin area on the top, waiting for my digger ... ). Luckily, I pinpointed...

I tested with :
an Iron nail, Hammer and Pliers
1-euro coin, small and big foil, copper glass,

No difference in audio. GB is working nice, but disc audio is not work....

My "... experience in developing detectors..." is no better than yours.
What I have too much is experience with various models, technologies and years on the real sites.
However, in the last couple of years, developing my magnetometers, I collaterally learned a lot about DSP and...

Hello, master ivconic.
If I had even 20% of your experience in developing detectors, I might have been able to help you.
I must admit that I learned a lot from you.
The circuit I want most is a deep-seeking, motion-free IB metal detector circuit.
Thank you very much for considering...

Since I'm "recovering" today and have too much free time... let's make some sense of this topic, ok?
What I am about to write now is my long-standing desire for a "perfect" detector.
Anyone who has been on the forum for a long time certainly cannot avoid my frequent scribal...

What runs through the whole story is actually a very worrying and sad testimony that the days of metal detecting with a successful end of the day (a lot of good finds) have long passed!
That's what I had to go through in one day, to find a low-quality iron fibula!
I remember much better...

I did a basic schematic, most of which is taken from well known Bi-Polar PI scheme. This is just for the concept (the schematic is not complete, and is missing some important parts). The initial firmware will be simple just to see if the darn thing will work at all. It belongs in a different thread...

Oh yes!
Everything that doesn't kill you - makes you stronger!
Given the crazy head on my shoulders... I'm probably the strongest man in the history of the planet!
I have been so lucky in life so far, and in many more dangerous adventures, that it is absolutely clear that God is protecting...

Yes, that's a shorter version of my explanation! Hahahahaha!...

Ha, ha, ha!
Great point and you'll love the answer!
Yes, the basic obligation of the medical staff in the "emergency room" is to ask about the cause of the injury!
In case of questionable answer; they are obliged to call the police officers on duty.
I had that in mind....

New fear unlocked.

My Vaquero is working fine. WAS.

I packed it for a trip to Virginia over a weekend. AirBnB was in an 'old' part of town. I pulled out my machine, and it just screamed a threshold, with no control. The all metal mode made a slight change in pitch....

An adage I like to use is: "A good day is any day I learn something new." See? Your day wasn't as bad as you thought. And you still have your fingers.

Did this machine ever get repaired?...

What targets are you using? This method does not discriminate between ferrous & non-ferrous, but between low conductor and high conductor. Try a small piece of aluminum foil....

I took a sample of the LF357's output, but I don't think it's genuine—what do you guys think?

It's very hard to find a real one around here, but as I said, it works without much trouble even with the LF356. Still, I'd like to get an LF357 or a good replacement to put it to the test and...

i hope its not the soldering iron using hand
by the way
since you gone to the hospital with a gunshot wound did you have to explain how it happen
and did you have or expecting a visit of the police?
take care next time

I’ll tell you something even better: my daughter asked me why I had a black thumbnail, and my answer was, "I forgot how to use a hammer."

Thanks!
True!

We wish you a speedy recovery, but you made a catastrophic mistake today.

BTW the reason I didn't bring the lightweight Deus and opted for the super heavy duty GTI2500 is because the GTI2500 in AM mode has no competition in these types of quests.
Literally!
The GTI2500 is unassailable!​

This evil "beetch" is finally harmless…
I keep staring at it, turning it around in my hands, wondering what the hell I could make out of it…
because apparently, nearly blowing my fingers off wasn’t enough to teach me a lesson.
Any ideas?

​

​​​​​...

Thank you dear friend...

Hi all friends .how to send data from joker resistivity to computer.I tried many times but in vain...

​...

Here's What Happens When Ivconic Tries to Be a Smart A.rse !!!

Well, boys, I think I've officially earned the **Dumba.rse of the Year Award**. And the best part? I have absolutely no one to blame but myself.
After months of inactivity, I finally decided it was time to get back out...

@dbanner



You could take a couple of late samples with the ADC of the steady state DC value of the signal.
Then adapt the slicing level to the comparators accordingly: eg keep the slicing level a steady 0.5V lower than the "ground" level.
Slicing voltage...

Do you think it can be because of my damping resistor (680R)? Maybe the value is high.
Should I change the value of this resistor to 330 ohms and use a new inductance?...

Hi,
Now, I publish the current schematic of one high power PI detector with ground balance feature for the thrill-seekers in forbidden places. The search coil have to be 1x1meter with 300uH inductance and 0.4oHm resistance. The energy in 3pcs. LiPo 18650 accus is enough for all day searching....

Check this one. Is it better? I dont think it is the final version as I see some mistakes. I found the drive where they are on, but the Designspark EDA does not seem to open the files anymore. It looks as if I used 4 samples. An induction balanced coil, using a bucking coil. The timing was probably...

...

Dear edurado
TGT = 10us
GB=10us
EFE1=320
EFE2=340
All sample width is 20uS
I attached scope for GBdelay (9.5)
My testing targets are a foil and Iron hammer.
My coil size is 10cm, it is small for testing.
...

I'm pleased to share the coils atlas v2
https://drive.google.com/file/d/1N84...usp=drive_link

If you have any coil data, pin map etc. - please share. I'll add it to the next revision of the atlas.

The changes compared to previous version:...

Your timing settings might be incorrect, or the connections to the CD4066 synchronous demodulator are likely wrong. At point A—with the GEB potentiometer set to a mid-range position—high-conductivity metals should produce a response opposite to that of low-conductivity metals. In my opinion, you...

I checked the "A" point on scope, no difference. All targets first increase.
My GB is working, but no disc on Audio.
My coil is mono, 500uH+680R....

MAB357...

If you probe point "A" in your schematic, does it increase for one type of metal and decrease for the other?

thanks
...

Thanks....

In the tests I’ve conducted, the LF356 works without much trouble; thanks to its advanced discrimination algorithm, it doesn't pose an issue—in fact, I even used the TL081CP successfully.

However, I haven't been able to use the suggested replacements.
If you can't find the LF357...

Thank you so much

I did add a few extras, but not that many.
I don't seem to have them either, but will try and find some replacements....

With the PIC18F16Q41​ you have a clock speed of 64 MHz = timer resolution of 16 ns. Which doubles the resolution of Pickini V4
You can gate TMR1 with the comparator outputs.
The comparators should have hysteresis.

Looks very promising.
If I had time I would redesign...

fly on the moon! ...

And now a few words about the sensors.
I took the famous FLC-100 sensor as the main reference for working on projects.
However, I was fortunate to have a collaborator in China, a very smart and educated young man, who dedicated himself to developing quality sensors.
And after 3 years...

So even though my posts are chronologically disorganized; the true chronological list of development to arrive at the final WS43 project is as follows:

1) 1.8", ESP32-S, no "Touch", no external ADC, 1 sensor.
2) 2.8", ESP32-S, "Touch", no external ADC,...

One of the "transitional" projects is the WS2, which has a 2" TFT Touch screen and an ESP32-S3 processor.
It was the work from which I added an external ADC.
It was the "key work", which showed me the direction in which I had to move further in development.
...

The simplest project is with a 1.8" (non-touch) display.
"Null" is a physical button and "Sens" is a physical potentiometer.
It is designed as a small manual pointer for very fast tests.


​...

This is a good example to compare the power of ESP32-P4 and ESP32-S3.
On this project with 1 sensor and a gyroscope, the main processor is ESP32-S3.
Considerably weaker than ESP32-P4.
The grid is a fixed size of 5x5 and isometric 3D rendering is obviously slower and of lower quality....

...

Before the final WS43 project, I did several "lighter" and simpler projects.
One is particularly interesting because it only uses 1 sensor and a gyroscope and serves as a pinpointer (up to several meters depth though).

​...

...

Both on the first video and on the video showing the Windows software; you'll notice the example records named "Tomb" and the "Spear".
It is a real shot of an ancient Roman tomb and real shot of the iron spear.
The recordings are "embedded" in the memory of...

In order to support the project, I also wrote a simpler Windows software for importing and manipulating .csv files from the device:


​...

Yup!


​...

Dear Carl
My PI ( based on polarity ) is working nice but i tested it for ferrous and non-ferrous metals.
Unfortunately, i have the same pitch for all metals, while your video is high/low pitch for different metals.
Do you have any suggestion for checking?...

Thanks dear eduardo...

Hello Bernard,
What is your opinion on using (temporal sampling) the Microchip(specifically the PIC18F16Q41​) with a bi-polar (H-drive)TX and this RX front end:


​​​​​

A microcontroller's internal hardware comparators can only handle positive voltages relative...

Half of them are back... the other half, I don't have. George, did you add these?

Yes, looks like all the smilies have gone. Only the words are showing, but no images.

I can see them listed in the Smilie Manager but I suspect the actual images don't exist "images/smilies/smilies/".
One for Carl to fix ......

To the admins: guys, the forum is still badly damaged and half the functions are not working!?
Any chance of fixing it?
This is how I see the forum, I have no chance to use smileys or format the text correctly?!



​​...

​

​...

New free web space found:

http://www.projects.byethost31.com/M.../V4/intro.html...

oh oh oh... where our lover font COMIC SANS MS? hot offer began?

Overview

I am offering for sale a fully developed, completed...

I designed this audio circuit for the Bipolar PI, which uses the battery's negative terminal as ground. Your current detector, which you're building, uses the battery's positive terminal as ground, so this circuit won't work for you without some modifications. First, D15 needs to be reversed for it...

The mono coil is a multi-dimensional problem because the same coil is used to both transmit and receive. For a fixed TX voltage drive, a lower inductance generates a stronger magnetic field which adds depth. But on the RX side, a higher inductance generates a stronger RX signal. So these two factors...

...

...

I suspected the audio circuit, so disconnected R18 (one pin) and connected it to my Subtracting GB output.
What is interesting is that my sensitivity is lower than its original!
My conclusion is that Mr. eduardo's Audio part has a problem and my low sensitivity is because of it.
...

Hello Dear Carl
I hope you are OK.
As you know, I have already built HHD with GB. Please see following, it is my GB method (Subtracting GB).


After that, i connected Mr. Mickstv's audio pcb ( following) to out of my GB (G1) . But before connecting the Mickstv's audio,...

It's not a secret, and it's even less difficult to assume that I compiled that document with the help of AI (albeit with too many iterations, because the AI ​​kept hallucinating, as usual).
The idea is clear in my head, but due to the lack of formal education; AI comes to me as a super helpful...

Hi ivica,



now ask the AI in the same manner
to analyse the processing means (a scientific paper), where X response is minimized and the R response is maximized
and how this can be realised in metal detecting technology.

Aziz...

Regarding the advancement of metal detector technology, it can be said that we have reached a situation where we are trying hard to "squeeze a drop of water out of a very dry tree", right?
That is why now is the period when a complete retrospective of everything that has already been...

Hi ,maxe I have a few PCBs: MPP-Beach, Mini Pulse.
https://www.ebay.de/itm/116940158776​

It would be interesting to add coils from Eq 900, and X Terra Elite..
I heard some opinions..that the coil from Equinox 900 works better on Equinox 800 than the original coil..​

Such random pictures on the Internet are "dangerous" because they drag me into deep philosophies, here is what one picture from the Internet provoked in me:...

You will find this interesting I suppose:

https://voyager.gsfc.nasa.gov/Library/VOY_Notebook22.pdf...

Not sure if I should use this same thread for this question:

I want to make a custom battery (smaller in size) for my GPX 5000. Do I need all the board that comes with the original GPX 5000 battery (I assume this has some kind of audio amp on it) or can I make a simple circuit (BMS + regulator...

The Compass Forum ceased to exist as approx. July-August 2026. No warnings, explanation from forum owner....

Hi Maxe,

To my knowledge, there is neither a circuit board nor assembly instructions for the Superscan.​ Often, people only post a circuit board drawing or a schematic. If someone posts a schematic, you should be happy. Because posting a circuit board drawing is useless in most cases.

Hi all,

the promissed amplifier schematics:
- 9 V Version with NE5532
- 4.5 V - 6 V Version with OPA1612

See the LTspice simulation files please.
Cheers,
Aziz...

Сказки Венского Леса. like moon landing with this lady keeping program listings from bottom to your head.

Thank you very much, and I wish you success. I wish you had the PCB design for that circuit you sent (or at least a PDF guide), but I am grateful to you nonetheless. I am using a translator, so I hope my message has come across clearly....

Hi Maxe,

If you're a beginner and want to build your own metal detector, I recommend the Geotech MiniPulse. The project is well documented step-by-step in a builder's guide. A working circuit board is also available. Ideal for beginners. The MiniPulse is also an excellent metal detecto...

[QUOTE=eduardo1979;n453273]

I will definitely follow your advice, and I want to choose a simple variable power supply as my first step for learning. But once you have a ready-made schematic file for a board, all that's left is buying the parts and placing them, which anyone can do. That's...

[QUOTE=eduardo1979;n453273]

And thank you for sharing those figures and taking the time for me....

[QUOTE=maxe;n453272]

I completely agree with you, but as a beginner, I recommend starting with a simpler detector....

[QUOTE=maxe;n453271]

Hey, I’m actually new to this website, and I’ve mentioned a few times that I’m a beginner. Everyone has to start somewhere, right?
I’m really interested in electronics, and I’ll probably study it at university too. My goal isn’t to become an engineer...

I wish there were a guide on how to use the site. I’ve seen several people asking for a specific map that was actually already available on the site; this indicates that they aren't able to use the site properly....

Good old fortran code my experience was way back in the mid 1960 we had to get the code punched in to cards and sent to Melbourne Aust. to see if it worked. thanks for mentioning fortran.

​
...

Hello Maximo.
It seems you like having everything handed to you on a silver platter. If you took the trouble to look at integrated circuit U10, you would realize it is similar to U9. The pin order from top to bottom is: THR=PIN6, DIS=PIN7, Q=PIN3. Attempting to build a Superscan PI detector without...

What are those numbers below the red line—the one I’ve outlined in green? I can see the numbers 6 and 7, but the other one isn't clear; could you write those numbers out for me from top to bottom?

Hello Altra,

Thank you very much for the explanation. That's well explained and makes sense.​

Hi Geomax

When the signal goes higher than about 0.6v the diode begins to conducts through the 4.7K and becomes actively parallel with the 47K. The lower resistance causes a rapid increase in vco audio frequency. When the diode is not conducting the LM555 only see's the 47k so the vco is...

Hello,

I've asked about these three components before. So far, no one has been able to give me a satisfactory answer as to why there's a diode in the circuit.​

Excuse me, that red square is covering three numbers; could you tell me what those numbers are?...

Your idea of using two coils is very interesting; I even saw an image where a professional coil—made up of two separate coils—was mounted on an X-Scan unit (I believe I saw it on this very site). Could you explain a bit more about what I should do?I am a complete beginner and need some guidance;...