Homemade metal detector

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Hope all goes well with the bfo mate get on the Mullock heaps around bendigo no probs with noisy ground .
Tath mate look up the minelab coil connector images you will find a diagram to fit a standard coil tech nugget finder coil to unit .mine screams on a .2 grammar .you need to disconnect 1k resister from mosfet and connect coil wire direct to 1k that you remove from mosfet this will allow you to run dd coil.if you need diagram let me no and can organize one .Don't use the buzzer fit a headphones jack in its place this unit does find gold .
 
Drbean said:
Hope all goes well with the bfo mate get on the Mullock heaps around bendigo no probs with noisy ground .
Tath mate look up the minelab coil connector images you will find a diagram to fit a standard coil tech nugget finder coil to unit .mine screams on a .2 grammar .you need to disconnect 1k resister from mosfet and connect coil wire direct to 1k that you remove from mosfet this will allow you to run dd coil.if you need diagram let me no and can organize one .Don't use the buzzer fit a headphones jack in its place this unit does find gold .
Click to expand...
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Going to go one better. Using a balance transformer out to a Class D amp I have. I have seen the DD construction notes and it has my eyebrows lifting. I am going to start on it shortly and Thank You.
 
G'day guys,

Been a while since I have posted, my apologies, been running around like the proverbial blue bum fly, so the build went well itself, but couldn't get it working properly, my mate is working on his to try and work it out. No news to report yet sorry..... Having to remake the coils to suite the housing we made for it, as we made it, the coils were not overlapping :(. I hope I will be able to give an update soon!

Cheers

HH
 
Thanks for the update HH, I'm looking forward to see how the thing performs and if its worth doing myself.

Good luck
 
Hi mate did you say don't think coils are overlapping if your making a DD you need to null them look up matchless detector plans show how to do this mate .Hope you sort it out Dr.dont be afraid to take it into Jaycar they are always willing to look at it and give advise . :D
 
Third time at attempting this post, sorry guys.... I saved this post this time in the event I need to try a fourth lol



AtomRat

Hey mate, I am confident in my mates work, but it doesn't hurt asking the question for sure, perhaps it is worth another look... he wasn't happy with the design using resistors as capacitors if that makes sense to the electronically minded, so in him saying it might not be that great as it is I went looking for other circuit boards, found this one for $65ADS 2 Deepseekerfrom this site:http://www.treasureenterprises.com/metal%20detectors/Metal%20Detectors%20%26%20Accessories/garrett_metal_detectors.htm#SECOND-HAND





DrBean

Thanks for the heads up mate, I will check it out when time permits, but before I complete the coils :p might be well worth a trip down to Jaycar with the gear.......



Also while I was looking about for circuit boards, I spoke to someone in the northern hemisphere, actually spoke on the phone. Long story short, he tells me metal detectors will not pick up small amounts of gold, of around a few grams or less, he told me it would be lucky to pick something up that is in the ounces..... I didn't end up following up circuit boards through this fellow any further, he would refuse to sell it to me anyway since I would like to find gold as well as coin and other interesting metal artefacts.....



Pictures of the project will come shortly as well :)



Sorry for the slow updates guys



Cheers



HH
 
i saw an article where he used a frisby for the coil holder but anything plastic would be fine , you could also make the coil on formers and then cast it in epoxy resin so make a mold for it
the other idea i have for myself would be to make my detector compatible with minelab coils and going as far as to make my connections to the coil the same fitting and same for battery if it going to be external , however i am thinking i will use lithium iron batteries as they are very light and the battery on my old 2100 is a bit of a pain

about BFO detectors they were invented for use in mine detection during ww2 i think, but they are wrong for gold and precious metals

the best type for gold detecting are pulse induction these inherently ignore noisy ground which has plagued other types of detectors

I am considering trying to build my own detector and have been looking at circuits and also looking at youtube videos of them working , nothing i have seen so far really tickles my fancy

I look forward to seeing results here , if i go ahead and start to build something i will post it here
cheers Ron
 
Hmm Harvey, I am not understanding the "using resistors as capacitors" at all, they are completely separate components in my eyes..

Good little site you found there though, I might be able to replace one of my turn knobs through them :)
Did you buy the ADS Deepseeker circuit? It doesn't explain much info on the site as to what comes with the board. It almost states its just the circuit board and no components, which would not be nice for $60 lol.

Making your own PCB boards are rather easy if you are interested in that at all too, theres a lot of info on it online. I used to use a black Sharpy pen on blank copper PCB from Jaycar and etch it with a 50-50 mix of hydrochloric acid and hydrogen peroxide.

Ronk said:
I am considering trying to build my own detector and have been looking at circuits and also looking at youtube videos of them working , nothing i have seen so far really tickles my fancy
Click to expand...

It is a bit hard to choose as they all seem a bit .. well .. you know. It would be better to have a go at your own if you have the know how! Hope I can help out with something at some point. Would you be designing a complete circuit, or using something like an Arduino or PIC?

( PS: I have a PIC programmer board if that is useful to anyone, but its the basic from Jaycar. Can program chips up to 64 pins )
 
well the only thing i am basically settled on is PI , and it seems to me i would need to vary the frequency or at least have it switchable to about 3 different frequencies , I can do all this the old fashioned way but i guess now you can do it with computers too . I have had a little experience on arduino and nothing at all on pic
When i first learn about electronics it was all valves lol

the next problem i can see is figuring out how to negate ground effect , I dont know if this can be done with computers ,

and lastly gain vs noise it seems when we try to get really high gain we get lots of noise so it would need some research into that . the trend these days seems to be going digital so only process signals that are on or off but i think we would need some analog preamps before we go digital

any way just putting my thoughts down on paper

ps i work in electronics on a daily basis and i can make pcb so if you have design you need to get a pcb for i could help

pps i am hireing a sdc2300 in a couple of weeks, love the vids on youtube about them, makes my old sd2100 look like junk (looking for possible mods for the 2100)

Ron
 
AtomRat said:
Hmm Harvey, I am not understanding the "using resistors as capacitors" at all, they are completely separate components in my eyes..

Good little site you found there though, I might be able to replace one of my turn knobs through them :)
Did you buy the ADS Deepseeker circuit? It doesn't explain much info on the site as to what comes with the board. It almost states its just the circuit board and no components, which would not be nice for $60 lol.

Making your own PCB boards are rather easy if you are interested in that at all too, theres a lot of info on it online. I used to use a black Sharpy pen on blank copper PCB from Jaycar and etch it with a 50-50 mix of hydrochloric acid and hydrogen peroxide.

Ronk said:
I am considering trying to build my own detector and have been looking at circuits and also looking at youtube videos of them working , nothing i have seen so far really tickles my fancy
Click to expand...

It is a bit hard to choose as they all seem a bit .. well .. you know. It would be better to have a go at your own if you have the know how! Hope I can help out with something at some point. Would you be designing a complete circuit, or using something like an Arduino or PIC?

( PS: I have a PIC programmer board if that is useful to anyone, but its the basic from Jaycar. Can program chips up to 64 pins )
Click to expand...

G'day AtomRat
I think I have put on display my ignorance for electronics :p
I did not purchase the board, and as you stated, if it doesn't come with any of the components it is quite costly.
I think I might start looking around on the net to make my own PCB, with limited searching for PCB's I have stumbled upon tutorials to make your own, some of them looked pretty scrappy, but, I guess, it is not what is on the outside that counts right? haha

Sounds like a good project to burn through some time as well, when my 10 month old allows some free time I might tackle it soon!

and Ronk, have you come across any plans that tickle your fancy? in everyones opinion is it a matter of the higher the complexity of the circuit board the better the possible results?

Cheers

HH
 
hi Everyone

i dont know if i agree that the more complex the better, i would think just be as complex as necessary to get the job done

computers vs analog i current;y build equipment for the horse breeders and i have designed them from a completely analog standpoint and they work very well, there are a few opposition that have used pics to do the same things as i do with analog

both work well so why change ?

now my personal experience with detectors is I have built the sandlant pi about 10 years ago and never got it past bench testing but i did look at it with my CRO and the waveform was good and i could see the decaying wave change when i passed metal by the coil .

so it worked but not well enough for me and i ended up purchasing my ML2100 which found gold by both me and wife with no experience
some here in vic and some more in WA when we went there for 3 months (must say I absolutely loved it over there ) but since coming back home we have tried it out a couple of times and got nothing so tended to do other things. I have a friend that has a ML3500 and finds gold quite often around here so it got me thinking about trying some more over here , I took my 2100 to his place and he dug a hold in back yard and said can you find that , (this is his normal test gold nugget) after some mucking around i had to say no, so he open hole and moved it up and we tried again and no again and we brought it out of the hole completely and tried again and no

hmmm why am i even bothering with a 2100 , is my reaction .

so i contact minelab and tell them my 2100 is dead as a maggot and ask them to take a look , to which i was told sorry it too old we dont have parts for them .

next i found out about woody (frankston) he would make it go for $700 a lot a $ imo so I haven't gone that way either , so I decide to have a look at it myself open it up and it all white everything is painted so no easy way to identify the parts, but i can see where the wires come in and out and i make some guesses about what is what and why, and try out some probes and see what wave forms i can find , from my observations it is working as good as it was ever intended to , however i can watch it react to my 0.1gm nugget and not make a sound even tho the CRO sees it moving closer so probably losing about 1 inch ( 25mill )of detection , the other thing i had to turn off everything even the electric fence and my laptop to get it quiet , only the slightest warble now . So moving around the unit with my probes looking at everything I could look at, I decided the supply ripple was quite high so I slapped a 4700uf across supply and it took a lot out, but not all. that is with the standard 6v lead acid battery. . I have been busy since then and gone no further .

so there is no quick fix to detectors but my dead 2100 leaves everything i have seen from DIY builders for dead so far

PS I took my .1gm to my mate and got him to setup his 3500 and it found it very well up to about 2 inches I then went to EEday in Ballarat and got a test of the sdc2300 and did the same tests out in the street and there was still a lot of noise but it detected it quite well , so i am hiring it for a weekend Sat week and will try and find some gold with it , wife was talking about buying a 5000

I am still happy to help anyone trying to build their own detector just inbox me , but I am thinking might be a whole lot easier to just buy one , I guess it is a time vs money thing on what we do

one last thing when i first bought this 2100 it cost $2000 we have just over broken even with it my even be up a $1000 now with some of the gold we have left over
but even then it was dead compared to the gt extreme we met at tarnagulla the guy "Steve" had just bought one and was finding targets we could not find when he invited us to try over his marked spots.

I intend to try some things on the 2100 see if i can get it more responsive as I get more time but we are in the middle of our busiest season ever and honestly I have not had a lot of time

cheers all Ron
 
G'day folks,

Thought I would let you all know that there has been no further progress, thanks for your opinion Ron, I like to hear different points of view :)

After much consideration and with the limited budget I have, I think I will end up buying a Garrett Ace 250, I am not going 100% gold hunting, as I live so close to a beach, that will be my main point of interest, although, I will plan holidays out west a little to go panning/detecting out at Warwick SE QLD, I am a year off going though, have a strict budget for the next 18 months, may get out in the meantime and have a crack at panning though :) sure hope I can contribute a photo in the finds section!

Cheers

HH
 
hi there I have decided to attempt to make the Hammerhead pi detector

also i have been reading the pi article by J A Corbyn this detector is for finding big deep gold he says he found 50cent size brass at 750 mill

i would love to try this in spot i know in WA

SO i guess i might open a new thread for this

Cheers Ron
 
I bought a coil housing from ebay. It cost about $20 US plus postage. I thought it was worth the expense on a build that's trying to keep the costs down. Search for metal detector coil housing.

Cheers
 
scotthbutler said:
I bought a coil housing from ebay. It cost about $20 US plus postage. I thought it was worth the expense on a build that's trying to keep the costs down. Search for metal detector coil housing.

Cheers
Click to expand...
be nice to see a pic of it
 
I'll put up a series of pics when it's finnished. I'm still waiting for it in the post. Shouldn't be too far away
 

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