Full m/lab SD2000 schematics

[Finderskeepers]

Nice work g.s.

Yeah it's fustrating project, but when setup correctly it works sweet. You notice that it built up areas the machine becomes noisy from emi, so to test it best to travel few km's away. I also did the same error with the lm13600 . Click on http://www.geotech1.com/pages/metdet...s/FastCoil.pdf this should help you. Furthermore, pay attention to the connection required for the 2x10 turn ground balance pots, otherwise you cannot balance the machine.

[g.s]

mec I found this to ebay You can check,whether it is suitable code is ( 160804525923 )...

[g.s]

thanks mec : ...I had the WRONG link tlc271 pin 3 with 2χ110 κ resistors can not have drift 180volt .
have a look at image below.

fix the problem g.s

[Mechanic]

Hi G.S.

I have a feeling that the coil is too high resistance and the copper is too thick. Check the voltage on the 200v cap, it should be around 180V. If it is close to the 180v, check for a signal at the gates of the N and P front end fets before the lm394. Check that the fets are turning on at least 2.5us before the first sample is to be taken.

If the voltage on the 200v cap is not high enough, try adjusting the value of the 2X 110k resistors near the 200v cap to lower the snubber setpoint, this may allow the detector to fire up. Failing that, remove the byv28-200 that goes to the coil(stop the transmit pulses going to the coil) and remove the 1k resistor shown in the schematic just below the 40106. This should allow the front end fets to start working and the receiver to start working, although it will not detect metal in this state. Then get a magnet and wave it past the coil, the magnet should make a signal. If it does, this is good, later we will tune the 3 trimpots to cancel the magnet, but first you need a suitable coil. Borrow one if you can. If not there are many threads on here which detail the wire you will need to successfully build a coil for this machine. Here is one >> http://www.geotech1.com/forums/showt...oil-on-the-fly.

Also without a coil connected, try touching around the lt1057's and see if you can see a signal from the testpoints on the tlc27's, you will have to turn your scope down to say 100mv/div and about 1 second/div. If still no signal is seen, measure the voltage just before the 2.2uf caps at the output of the tlc074. This should only be a few hundred mV, if it is 4 or 5v, we have a problem further back in the cct. Then try grounding the output of the first ne5534(preamp) and repeat the above tests.

Cheers Mick

[g.s]

Do you have signal at the testpoints in the filter section at the output of tlc27m7cd?
What coil are you using?

Cheers Mick

NO I do not have signal at the output of tlc 27m7ipe4 in point test .tp. only one tone at the beginning of operation For a few seconds.
it coil SIMPLE it is a test as the photo.300 uh 2 ohms copper enamelling 0.6 mm .

ALSO using crystal 2.048 mhz and 1.84320 mhz in my test, are subjects this Vitality the system.sorry trying to learn It's tiring .THANKS mechanic.

[Mechanic]

Do you have signal at the testpoints in the filter section at the output of tlc27m7cd?
What coil are you using?

Cheers Mick

[g.s]

for and again to all by G.S. conduct tests and discovered that the channel 2 not working, When arming no signal at pin 4 end pin 14 from 4053. It is a problem from schematic,In your own SD He works correctly.Can you help to these the problem I have Thanks in beforehand and wrestling...G.S

[skorpio]

Hi geo C 99, and C is the value of more than 100 parts thank

[g.s]

test wire enamelling is not a good ,the result is crap...
I am looking for teflon wire knows someone that are available.Model or Number
if I use the internal cables TV ANTENNA..

[g.s]

THANKS mechanic Finally a little unwary the g.s except the mistake I have in lm 13600 I've done and ca3083 I've put no extin at ca3083 pin 9 and pin 13.attention Anyone making USES pcb by g.s should correction Those reported above.
Now I hear the song from SD GIOUPI!!! THANKS MECHANIC.

[Mechanic]

G'day G.S.,

Pins 1 and 5 are not to be connected. Pins 12 and 16 are not to be connected. You will have to do a little workaround to fix this.

Cheers Mick

[g.s]

THANKS mechanic I will check.a question still it lm13600 With a quick glance I did at pin 14 I do not have square pulses, In the my schematic I have jap silk pin 12 and pin 16.The same goes for pin 1 and pin 5 That is correct, the ERROR. again Thanks

[Mechanic]

Hi G.S.

just checked mine and the voltages around the ne5532 are correct. Check pin 15 lm13600 should have a saw-tooth wave that changes with adjustment of the tone control, pin 14 will have a square wave. Check that the threshold pot is adjusted to the 5- side, this should bring the audio on full. Check pin 10 ca3083, with the threshold pot set to the 5- position, pin 10 should read about 1v+, with the threshold pot set to the 5+ position pin 10 will read about -5v. Check the 4053 at the end of the filtering section, just before the audio section. Pin 14 should only have signals that go from gnd to 5-, pin 4 will have signals that go from -5 to +5v and anywhere in between, touch around the lt1057's while probing these pins and there should be an obvious response. Did you connect the enable pin on the 4053 to 5-?

Now with the 1057's, were these tests done with a coil or no coil? With no coil, on the gb channel output, I get a waveform +-2.5v. On the ch1 integrator output I get 1 drop to about -2v and for ch2 I get 4 small pulses that drop about 1v below gnd.
Check that pins 5 and 12 on the 4066 for the GB channel have the GB pulses shown in the schematic, they should swing between 5+ and 5-v. Check all your sample pulses are the same as the schematic. Check that your tx pulses are the same as the schematic.

As for coil specs, I would suggest buying a ready made coil new or secondhand. These detectors are really fussy on what coil you put on the end, if something is a little bit out it either won't work or will give really bad depth. You have built a really good detector(if you can get it to work), give it the best chance and get a good coil, building coils for these machines is a black art.

Oh and your damping resistor setup is correct. It helps when people look at the actual material you provided before saying something is wrong. The only thing I would have done differently is made the ground side of the damping resistors terminate as close to the coil ground wire as possible, but what you have should work fine.

Cheers Mick

[g.s]

the METERING LT1057. HELP. HELP. HELP.

[g.s]

HARDLY I gave catering in the circuit and the results are not good, not I have sound in speaker. at pin (2.3) from ne5532 l have 2.95 volt pin (1 . 6 . 7 ) not volt . pin (4) l have - 5 volt ok . pin 8 l hale +5 volt ok . pin (5) gnd ok . HELP ME