Dr Otek MT-12 Problem

[Bob Goodwin]

Hello! I just joined the forum and hope to be of some help. I’m Kind of a newbie to metal detecting (Couple months) But I do have an electronics background. Anyway, I thought that MT-12 might Be a simple unit learn on. All I’ve had is a older bounty hunter until now.

The MT-12 Had a problem right out of the box with some kind of interference around 50-60 On the scale, making it unusable. I noticed that a little Wiggle one way or another on the coil cable connector sometimes gets it to work great. I’ve soldered hundreds of those connectors on radio microphones so I know that it can be a bit of a challenge sometimes. I figured it was a broken pin terminal. I know the smart thing to do would’ve been to send it back, but I couldn’t stand to wait when I knew I had it figured out… That was a mistake. I knew I was voiding the warranty, but they were on special when I got it so as cheap as it was, I wasn’t too worried about it. What I found was some relatively poor solder joints, and the two shield wires with multiple broken strands So I just replaced the connector. That did not fix the problem at all. That’s when I figured out that just touching the cable anywhere was introducing a capacitive effect or something Like that and causing false indications. I’m pretty suspicious of the cable but I’ve been messing with it for over a week and it’s actually gotten worse.
The last
I’ll stop rambling. I was really just hoping from my paper notes and this picture Someone might offer me some kind of suggestions. The measurements are confusing to me if I have the pin out figured correctly. It’s been a couple decades since I got my electronics on, so I’m a little rusty. thanks in advance!
- Bob

[ivconic]

I had a problem at first to understand what "Dr Otek MT-12" is... Google found it, it's some Chinese detector.
The way you describe the problem first looks like a GND break in the coil or cable.
It all depends on how the coil is designed, what is the "Faraday shield"... is there any?
The image of the detector instills a minimum of confidence, that it is a detector that at least works.
It shouldn't work as bad as you described, though.
A coil generally has to have a "Faraday Shield", "Faraday Cage", "GND", or whatever it's called...
There are several methods of application, either over the turns of the wire itself or the inside of the plastic housing is sprayed with a conductive spray.
And that conductive layer must be connected to the GND of the detector.
When I say "GND" it can often also be "MINUS", it all depends on how the power supply is done.
You will have to use an ohm meter or a buzzer to check the connections inside the coil, especially the cable and connector, and another connector in the detector housing itself.
When it comes to a Chinese masterpiece... anything is possible and anything can be expected.
You did not take clear close-up pictures, especially of the inside of the detector in the part where the connector is connected to the pcb.
So, based on the little information you gave (sometimes one picture is like 1000 words),
I would say that it is an interruption/break in the contact of the "shield" from the coil with the main GND (or Minus).
When I take a closer look at the pictures (you covered the coil with paper)...
it seems to me that both coils are bare, none of them have a "Faraday shield".
And the inside of the case is sprayed with conductive spray, right?
As far as I can see, the windings are pretty "lose" and the bad Chinese plastic that holds them often warps and bends.
This generally means only one thing: "goodbye coil balance"!

[Carl-NC]

As Ivconic said, it's a Chinese-made detector and even though they usually work, they often don't last very long because of poor quality. My suggestion is to cut your losses and get a decent brand.

[ivconic]

"ÖTEK" is is a Turkish surname. And the product is made in China.
Either it is an attempt to create a business or it is a local "rebranding", which is often the case with some trading houses.
Direct import from China is very difficult due to regulations in some countries.
A temporary solution is a private initiative and large market chains.
Rebranding is an old trick to get around regulations.

[ivconic]

Ha! $200 off with coupon! From 3xx to 1xx dollars just like that!
The video clearly shows that the lit detector also "walks" the VDI randomly.
Good fun!
Random campers are advertising the product!
When you google this model, it has very aggressive advertising!
There are many links and many videos... for such a cheap and rather unknown product.
This looks like a clever marketing move to me, you buy a large amount and try to sell it as soon as possible!
A convenient toy for one-time use during the summer.

[ivconic]

Here: https://www.geotech1.com/forums/foru...tt-ace-250-prc
post #8, unknown brand and model. Price in China is $35 on larger quantities is lower.
Despite the fact that these are low-quality products, it is amazing for how little money those can be produced in China!
...
And here: https://www.geotech1.com/forums/foru...x-8#post438521
this looks like organized action!?

[Qiaozhi]

Someone I know had a Dr Otek detector, which I tested briefly. It was very slow to respond and lacked depth. Clearly a cheap low-end product that promises a lot and fails to deliver.
As they say: "Buy cheap, buy twice".

[ivconic]

Someone I know had a Dr Otek detector, which I tested briefly. It was very slow to respond and lacked depth. Clearly a cheap low-end product that promises a lot and fails to deliver.
As they say: "Buy cheap, buy twice".

True!
Same experiences with one I refered to on antother topic.

[Bob Goodwin]

Thanks for the review folks, but you’re preaching to the choir lol. Definitely a cheap product however performance is not an issue. it’s simply the quality is not there for it to last years. What really happened is the Amazon algorithm got me. I was looking for a metal detector and that’s what they put in front of me over and over again at a sweet price point. I hate that about Amazon. You see what they want you to see. Like I said, from the beginning, I should’ve sent it back. Im just trying to make my mistake work now.

I’ve been very suspect suspect of the cord as well. I think I’m gonna proceed with swapping that thing out. When I was replacing the connector, it took me two or 3 inches to get something good. Whenever I stripped the insulation off one of the shields, it would basically fall apart. The other shield was good but one of them just seemed brittle. I’ll make it work. That’s what I do! I need to get better educated on theory though. As FYI, here’s a couple other pictures including a couple caps that I think I inadvertently got a drop a water on.

stuck with this turd until I can move up. I think the next thing I can afford that my 60-year-old brain can deal with will be a Fisher F19 Really like that simple display.

[ivconic]

The pcb says "MD6088"... and that's the closest description to the truth.
It is a platform, a project, and everything else is "makeup".
I bet that the same platform can be found in about 10 more "various models" with different box designs and coils.