Full m/lab SD2000 schematics

[Finderskeepers]

Hi Mick

Thanks for the tip. Will be heading up to Creswick this week and will try tuning it there. Next door neighbour has a 2 meter diam. satelite dish which I think plays havoc on my other detectors too.

[Mechanic]

Hi,

To adjust the trimmers get yourself a speaker magnet and remove all of the metal so you are left with just the ferrite magnetic ring.

Then short across the 2 integrator you are not adjusting, leaving 1 channel active, then swing the magnet across one side of the coil. If it is out badly, you will be able to hear the magnet up to more than a meter from the coil. Adjust the trimmer to reduce the response from the magnet. You should be able to sweep the magnet within a few inches of the coil without a response when the correct null is found.

Do the same for each channel. This should reduce the noise you are hearing on the output. Also make sure you are away from emi when you are testing for noise. These things don't like suburbia!

Cheers Mick

[Finderskeepers]

Hello

Just got my sd2000 clone up and running. Only issue is when all three channels (ground balance, channel & 2) are working together the threshold tone rises and falls and cannot be adjusted with the threshold pot. However, if the ground balance channel is disabled, the circuit works well, despite surrounding interference. I use a 11" minelab commander mono coil and the circuit is very close to the original specifications. Only difference is the ssm2210 replacing the lm394 and a 1.2mh inductor, approx 3ohms in lieu of 1.1mh, 3.6 ohm. Furthermore, the 5k9 resistor between the 4066 chip and 500 ohm blue trimmer is not available, I cannot obtain a resistor of this value - a 5k6 and 300 ohm has been placed in series. Is a 5k9 resistor crucial to have the g.b. channel stable? Is there anyone that can advise to how adjust the 3 blue 500 ohm trimmers? Careful planning of this circuit is required if you want it too work.

A big thanks to Zed.

[Mechanic]

The front end fets need to be turned on at least 2.5us before the first sample is due to be taken. You will notice a small oscillation that takes about 2.5us to settle. Later on when you make your own timings you will have to experiment with turning the fets on earlier. There will be a point where the settling time starts to take longer, this is the earliest time you can turn the fets on.

Cheers Mick

[talasumo]

Thanks Mick,

Someone help with signals that control front end fets? I try to make sd2000 but all pulses are generated from MCU.i need a exact timings and pulse width of these two pulses?

[Mechanic]

They sure are real! Make sure you have the signals going through the correct resistors and also the samples have the correct polarity. The GB channel samples are opposite in polarity to the other 2 channels.

Cheers Mick

[talasumo]

Hi guys, i build Modified SD2000 and i want to be sure these timings are real?

[ghaj]

Hi ZED

Has anyone build and tested this unit???

Thanks
Guy

Hi Guy. I have tried to construct one. As I have tested, there is some problems in some parts of the circuits. Values of some resistors, capacitors, ... are also wrong. You know all these CCTs have been traced from a highly colored PCB and it is natural to hit such problems. Anyway I am trying to go on and solve problems step by step.
Thanks,
Ghaj.

[Ace]

this the zip file from Rapidshare,for everyone.

Can some one please confirm a supply polarity error of U21 on page 5 of CD2000B and also that the error has caried over to PCB design.
Thanks

[Ace]

Hi eyeryone, I'm looking for the SD2000 PCB files in protus or other format, if somebody could please email them to me I'd be much appreciative.
Thanks
[email protected]

Anyone??

[Ace]

PCB files

Hi eyeryone, I'm looking for the SD2000 PCB files in protus or other format, if somebody could please email them to me I'd be much appreciative.
Thanks
[email protected]

[Orbit]

I apologize for the incomplete question I thought the third channel on the channel Ground effect.

[Orbit]

I set a question Minelab 2000 at the third channel with whom he meat provided with a channel for all metals or meat canal for nonferus thanks .

[WM6]

Yes the SD2000 was Minelab's first PI detector it has been around since 1995 and much modified by many still a good machine in the rite hands.
Regards, Ian.

Hi IBGold

you are not clear regarding Guy-M question.

Do you really know someone that build working SD2000 as DIY (except ML of course)?.

[IBGold]

Yes the SD2000 was Minelab's first PI detector it has been around since 1995 and much modified by many still a good machine in the rite hands.
Regards, Ian.