Calibrating MD3010 correctly

[dbanner]

schematic and coil are similar to ace-250. files archived.

Thanks for these photos and schemes.

[Skippy]

"Oh, I tried but nobody help me. I draw complete PCB of GC-1023 ......"

Yes, I remember it well, and remember thinking you are doing it wrong, you need the real detector and PCB in front of you. I posted:
"The top side foil will be hard to see on a through-hole board.
I thought you were going to purchase one of these machines in order to reverse engineer it? How are you going to find out important things like the coil specifications ( inductance, resistance, internal capacitors, etc)?
I don't expect the coil data to be the 'special ingredient' of the machine, but it's useful to help in the general understanding. "

Hence why I suggested you don't buy one of the 'maybe ACE250-inspired' Chines clones, but buy the 1023. The ACE-A-Like has a micro in it, and a custom LCD, no point tinkering with it, not much to do. At least the 1023 is old-school, but with potential.

[dbanner]

"Oh, I tried but nobody help me. I draw complete PCB of GC-1023 ......"

Yes, I remember it well, and remember thinking you are doing it wrong, you need the real detector and PCB in front of you. I posted:
"The top side foil will be hard to see on a through-hole board.
I thought you were going to purchase one of these machines in order to reverse engineer it? How are you going to find out important things like the coil specifications ( inductance, resistance, internal capacitors, etc)?
I don't expect the coil data to be the 'special ingredient' of the machine, but it's useful to help in the general understanding. "

Hence why I suggested you don't buy one of the 'maybe ACE250-inspired' Chines clones, but buy the 1023. The ACE-A-Like has a micro in it, and a custom LCD, no point tinkering with it, not much to do. At least the 1023 is old-school, but with potential.

The 1023 is no longer "el cheapo", the price is up there with the ace250 clone, just a few bucks less, so why bother? If you send me a broken one for free, I will be happy to tear it down and reverse engineer. The challenge for me was to do it from just the photos!

By the way, I am confident now that I have some more knowledge that I could easily complete the reverse of the GC-1023 based just on the photos I have. I would have to draw the scheme, filling in the blanks by what makes sense. The few remaining dots should be easy to connect. There is just a few top side tracks that could be easily figured out.

The coil parameters shouldn't be too hard to figure out.

But I have become lazy man of late, an armchair metal detectorist and diy'er. Happy just to type away at the keyboard.

[Skippy]

The 1023 is also hard to find here in the U.K, except at a high price. I did look for a second-hand one for a while, mainly on eBay and Preloved.co.uk , but with no luck. Ebay UK seems very 'quiet' in the detectors section nowadays, many dealers listings, but fewer private sales. I'm out of touch with all the 'social media' trends, but it's been suggested that Facebook is where it's fashionable, and as well as taking the forum traffic, it's also used as a eBay/CraigsList/Gumtree/whatever alternative.
I'm not that interested in the 1023 myself now, too many other jobs and 'projects' , including the Equinox coil, and the Polish discriminating pinpointer.

And rather than being an armchair detectorist, I've been out hunting for real a lot more this year, thanks to my 'new toy' Equinox, which really is a very good machine, and brings sites alive in a surprising way.

[marcelo2112]

. It would be interesting to see if a more conventional coil topology (a DD type search loop, for example) .

Where to see how to build DD coil?
Where to see how to build DD coil?

[marcelo2112]

Anyone who can see the attached images, could you please upload them? I can't see them.
Especially those of the chernoff user, oscilloscope captures. Thank you.

http://www.md4u.ru/viewtopic.php?f=51&t=5329

[marcelo2112]

Would you be so kind as to analyze the circuit for me? Thank you.

[Skippy]

L3 is the receive coil
L2 is the bucking coil
L1 is the main transmit coil
L1 is intended to join to L2 on the PCB, with L4 the fine-tuning loop. But as you can see they are just joined wire-to-wire, and the loop is created some other way.

[marcelo2112]

Thanks, I am learning.
Can I create l4 for tests? Any idea of turns?
No scheme uploaded by Kt315 looks like, do you have any to see?
Thank you.

[Skippy]

L4 exists, it's the 2cm loop coming off the TX coil. You can of course add an additional loop, if you don't want to disturb the present one. This won't help your problem at all, in my opinion. The coil induction balance has no effect on 'poor discrimination' .

[marcelo2112]

FIRST THING YOU CAN TRY TO ADJUST THE TRIMMER POT IN THE COIL.

Connect the oscilloscope to the output of the RX amplifier, the loop set it to small possible but clean?
Thank you.

[dbanner]

yes, set rx for minimum output.