Hammerhead Home Made Metal Detector (HH1) Air Test
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- Опубликовано: 12 сен 2024
- This is a test of a home made metal detector (Pulse Induction), designed by Carl Moreland. Test is done outside, under significant electrical noise from various house appliances. The coil is also home made, with a diameter of 27.5cm, inductance approx 300uH using stranded wire insulated with PVC. There is a plastic wirewrap applied over the windings. The coil is shielded with Scotch 24 Electrical Shielding Tape. For testing I used Australian coins 50c, 20c, $1, $2, 1c, 5c and EUR1. For the larger coins, the detecting distance is approx 25-30cm, while for 1 cent the detection was a bit over 15 cm. I consider this detection distance is normal for the diameter of the coil. The signal is sampled approx 10us after the pulse.
I made two types of shields. For cheap one I used sticky aluminium foil. For the better quality and more expensive one, I used "scotch24 electrical shielding tape". Check videos on Google Image to see how it looks like. It is important not to connect the ends of the shield, otherwise you are shorting the signal coming from the target. The ground of the coax cable AND one end of the shield goes to ground of coax cable. Center pin to the other end of the coil. Use 280mm diameter, 23 turns, 325uH
Hi David, the yellow capacitors, tear-drop shape are solid tantalum electroylitic capacitors. They perform better than standard aluminium caps and they are more expensive. I replaced those capacitors as I was recommended by Carl. I had problems with noise and I tried various ways to improve it. In the end I found out the noise was coming from nearby surroundings (I was doing the test in an apartment and the electric noise coming from neighbours was really bad)
In the video I used a 27.5cm, but I can't remember how many turns it has. In the past I used a 20cm coil, which had 29 turns. You can choose any diameter of the coil, as long as the inductance is around 300uH.
Hi Itakeyourphoto. I only have the mono coil I built myself and I also have an older model DD coil from Minelab. Both are working. I think the mono coil is more sensitive than the DD coil. Unfortunately the Minelab oes not have any kind of ground balance, however due to the fact it is a Pulse Induction type, it has some inherent immunity to ground effects.
Inductance depends on the diameter of the coil, thickness of wire, how close the turns are, not only number of turns! If you have 23 turns on 280mm diameter, the inductance should be about right, maybe ±30%. Attaching the shielding will slightly change the inductance of the coil (it increases capacitance). It's impossible to measure 10x less than what you expect, check your meter. I made a mistake in previous post. Shielding of coax cable goes to one end of coil and to one end of shielding.
MsAlkon1971, you are looking at a newer model of HammerHead, that is built with PIC12F683. The one I built does not have any microcontrollers (although I've done some work on my own version of microcontroller version which sadly, I have stopped at around 90% completion).
ok, thanks for replay, i will try to make another one.
Hey how are you Nick? Just wondering if you tried a minelab mono coil on this detector?
Does it have any form of ground balance?
For help with adjustments of the detector, please join the forums at geotech1. There are many people willing to help and many of them are much more experienced than myself. Maybe I should do a video about adjustments, although Carl's document is very good and I used it when I made my adjustments.
Hi Nicolae, I made the hammerhead as yours, and now I am with the final calibration, I have seen that capacitors C14 and C15 not seem electrolytic, and C10 not have it installed, I would like you to help me calibrate mine, showing me you made corrections.
thanks for everything
Nice work!
Do you still have this detector or working on new/better detectors?
Hi Sam. At the time, I was working to make a similar detector, but using a microcontroller. A large chunk of the electronics would be replaced by the microcontroller and the controls would be digital with indication on display. I almost completed the software, but I am not good at designing PCB's and I avoided to start the design. In the end I abandoned the project. I still have the original detector and it is functional (but I dislike the sound).
Hi Tony. I think it is Rev C of the board.
Hi nicolae, mine also makes me sound, I would like to ask which is the opinion you have about professional use and for those who are on the market and circuits that are on the internet, if it is very good, or if there are circuits better . and secondly I wanted to ask by how much is the resistance Pot R23 ? ... and R17 and R19 100k I have them and I do not know if it is correct. thanks you.
Good sensitivity. Deeply "sees".
how did you make the shielding for the coil? i made the coil and then wrapped aluminum tape around it, but didnt let the both ends of the tape to connect, then i attached cox cable to two ends of the coil plus one wire connected to shields one end. Is it right? i made 26 turn coil ang it was 10X less inductive than needed... :( did you test the inductance with shielding attached?
I have a goldbug2 but it doesnt have good depth, but very sensitve to small gold(sub gram). Building hh for scaning for nuggets deep. I might do an arduino interface with oscope.
thanks
my friend
300uh
haw many ohm
coil
27.5 cm
ohm in multimeter
and sorry
Hi All, sorry, it seems I answered twice to some posts - I forgot I answered them in the past.
Hola Nick, falta que pongas un capacitor de 4700 uF en la placa del Hammerhead, el mismo va a la par de IRF740 entre pista externa de la pcb y source del fet, en otras palabras el positivo del capacitor a la pista gruesa que rodea la placa y el negativo a la pata source del FET y que tambien esta conectada a la resistencia de 1 ohm 1 watt de potencia. Saludos.
That is the Hammerhead II, built with the PIC. You can find the source code and compiled hex code in forums area: showthread.php ? t = 16038
and whats a best kit for you actualy?
Mr. Nick.. Can you give me this schema? Thank you
You can find the project here: www.geotech1.com/cgi-bin/pages/common/index.pl?page=metdet&file=projects/hammerhead/index.dat
you test coil is 27 cm or 20 cm
que version de la placa usas ? b,c,d?
so much thanks
thanks
i see pdf and daonlod it
but i see pic 12f683
???????????
How does it work on gold? Im getting ready to build 4 hh pis.
It is better at picking iron than gold. I went once to search for gold using HH and I could not find anything. I am not sure if a more sensitive detector would have found anything in that area though... I did not have any gold nuggets to do some testing in the field.
hello nick,i make also this PI detector, but i have problems after the tresshold and the sound. testpoint 9 is variable -3volt and +4 volt ? Doe jou have for me plaese a right schema of the PI THANKS
where do you buy a kit for buil it please
I made the entire thing at home, including the PCB. I did not purchase a kit. You can read the details in here: www.geotech1.com/cgi-bin/pages/common/index.pl?page=metdet&file=projects/hammerhead/index.dat
hello bro please how much turn and awg and diameter of your coi
Hi, I can't remember how many turns are in the coil. The description indicates the coil diameter is 27.5 cm and the inductance is 300 mH. Depending on how tight you wind the coil, you can get different inductance for the same number of turns.
RUclips does not allow sending web site links. Read the forum on geotech1 dot com.
You can build the coil with 29 turns 0.5mm enamel copper wire, coil diameter 200mm
thanks very very much
my frend
send wep site pleas
and howa many turn coil and wiry size
sory for thes
David, I am sorry for answering you a bit late, I had no idea you asked me something - I haven't checked this video in a long time. The capacitors you are see there they are tantalum capacitors. I advise you check the website geotech1.com and join the forum. You can ask whatever questions you have in mind and there are people with better knowledge than me who can help solve your problems.
A zip file
In which everything
circuite and digram and hex file
Thank you
cool
Will you do me in this device are very successful
The good news is that this detector does not use a microcontroller, so you can build everything by following the detailed instructions found on geotech1 dot com website. Look under the Project section and you will find a pdf article, with the circuit diagram and the pcb layout.
Hello
can you tell me your opinion about Hammrhead? Do you think it's a excellent PI?
@@ha.farz.2953 Hammerhead is an excellent metal detector for somebody who is looking for a project to build. It is well documented, it uses easily available components and it has been built by many people. It also has disadvantages, because the circuit diagram is rather simple. It is good for people who want to learn hands-on about this technology (Pulse Induction). Compared to advanced Pulse Induction metal detectors (Minelab, QED), it has a lot to desire.
Hello
Dear Nick F
Is it possible to tell me value of your damping resistor for 300uH and size of wire (AWG)?
Thanks
@@ha.farz.2953 The damping resistor is chosen based on the optimal response of the coil and it is dependent on the coil characteristics and cable parameters. The document for HammerHead is available here: www.geotech1.com/pages/metdet/projects/hammerhead/HHv1p5.pdf. For the coil described, they recommend a resistor of 680 ohm. A value that is too large, it will cause ringing and a value that is too small will reduce the pulse amplitude. If you have an oscilloscope, you can test different resistor values and select the one that gives the fastest response. By checking the video at 0:28, I can see the resistor I used was 560 ohm (green, blue, brown). I selected it based on the pulse shape seen on the scope. The recommended wire diameter for the coil was AWG 26. I don't remember what wire size I used, I made a few coils. The shielding is also important for the sensitivity to small targets. On the geotech forum, they recommended a shielding mesh. Later, I purchased the mesh, but One was made from copper wire from a degaussing coil of a CRT monitor. For others, I purchased teflon wire from ebay. I had plans to redesign the whole circuit using a microcontroller with LCD and digital controls, better audio circuit, etc. I made the program for the microcontroller, but unfortunately I abandoned the project when I had to design the pcb (I wanted to make it modular, so I can swap various parts of the circuitry, for research purposes).
ok thks
thnks
very much
my facbook is
aymn alkon
good luky
Wonderful beautiful and excellent
Please I want to hex file
pic12f683
Thank you