making your own coils

2e0bax · Jun 2, 2007

Ok you now know im one of those hams and seems a couple of others here (hi radio friends).
I have just returned from Anglesey which is an island in North wales and cutting a boring story very short i took a kids metal detector with me which belongs to my son. On the beach for a few days produced just junk but i noticed it lacked big time in sensitivty, now the coil is located on the end of a metal shaft and also attached with a metal wing nut and bolt. Im no expert but when tuning im tuning out these metal bits and reducing performance? The coil or search head is square and like small. Has anyone experimented here? That coil is the antenna it sends and recieves and if this can be improved then so can the finds?
This was a cheap detector ( 1 pound from a charity shop) and my son has given me the go ahead to cut it up, see if i can get some impedence measurments and make something better if not then nothing to loose.
Im a dabbler and will post anything that works, again anyone done this? Anyone build there own coils? If so how you go about it? Sean / 2e0bax

chopz54 · Jun 3, 2007

Hi, You did not say what type of MD it was. Is it a BFO machine?
Better still what make is it? If it is an older model I have details on these.
The bfo,s I have plans on how to make the whole machines inc coil windings etc. I have read that the vlf machines really need the use of an ocilliscope to tune the coil to the detector. Any way please let me know?

Chop England.

Ps Got an old c-scope bfo but never use it. as they require frequent retuning when searching.This machine also has a metal pole n/bolt.

2e0bax · Jun 3, 2007

Thanks for the reply Chop, i have opened the coil up and looks like a TR machine but in all honesty this is one of those orange toy detectors but the only thing i have at the moment. I have some sites with the BFO plans on so i think im ok on that one as i dont want to build a detector at the moment.
I will take some pics later. Sean / 2e0bax

2e0bax · Jun 3, 2007

This is the toy detector as i call it but 100% better than nothing:tumble:
If you look at the coil pic you can see 2 coils and a small pcb with a single transistor a couple of caps and a couple of resistors. One coil has two wires but the other has six wires so it has 4 taps and these go to the pcb which i do not know what it does. I shall count the turns if i can and start playing without the pcb.
If you look at the coils where they cross this is where they detect and i have tried several different metal objects some having to be held almost between the coils to be detected!! Got to be worth playing with. Sean / 2e0bax

wishooter · Jun 3, 2007

I Saved an Article from Electronic Musician Magazine. January 2003.
The Art of the Creative Short Circuit. A Beginner's Guide to Circuit Bending.

They Take Talking and Musical Toys, Open them Up and Solder Various Components Like Potentiometers, Switches, Resistores, Capacitiors, and Leds.

To Distort, Change Frequencies, and Create a Bizarre Different Sounding Toy.
Here's the Disclaimer Thing and it's in the Article too... "THINK SAFETY"

Anyway, Maybe By Tapping on Different Wires, You could Tweak it a Bit.
You could Make a Type of Homemade Pinpointer Possibly...

chopz54 · Jun 5, 2007

Have seen these at bar boot sales. Would think with such a small search area

between the 2 coils " boosting " it would be very difficult, taking into

account the very limited circuitry this machine would have in its box.

Its more like a pin-pointer ( minus the ferrite rod ).

You could try altering the shape of the coils to make a bigger search area.

( more oval ). Good Luck. Chop

making your own coils

2e0bax

Junior Member

chopz54

Senior Member

2e0bax

Junior Member

2e0bax

Junior Member

Attachments

wishooter

Elite Member

chopz54

Senior Member

Similar threads