LOOKING FOR GOLDSCAN 4 Schematic.

[kt315]

7912 regulator pinout is NOT as 7812. look in google.

[David222]

Greetings.

My GS5 Lite is now working well. The previous issue was due to the PCB not being a true two-layer board as per the original design, but rather a single-sided PCB layout, combined with a counterfeit NE5534 IC and insufficient grounding, as well as unnecessarily long trace paths. Now the problem has been resolved.


Instead of using the NE5534, I have substituted it with an LF351. I have applied offset adjustment to pins 1 and 5 of the LF351. I am using a 300µH coil with a 470Ω 5W damping resistor, and the waveform at pin 6 of the LF351 is correct.


I am currently testing the device. At a 10µs delay, the ground balance does not match properly; it only works correctly at a 23µs delay. The low-tone/high-tone discrimination is functioning correctly. However, what I need is the 10µs delay.


I have also tested with a 250µH coil, and the device still works correctly at the 23µs delay with proper ground balance and tone discrimination.


Frequency: 3 kHz
Pulse width: 100 µs


My current question is: what adjustments or changes are needed to make the device work properly at a 10µs delay?


Please kindly provide detailed technical information and support, respected teachers.

Hi. I've been working on this circuit for about ten days, and I exactly built Eduardo's schematic. But when I set the frequency knob to 1k, the 7912 regulator gets overly hot. When I change the knob to 25k and use a frequency of 1300Hz, the regulator voltage fluctuates by 5 volts. The VR3 potentiometer really doesn’t do much. The loop resistance is 2 ohms and its inductance is 440 microhenries. If I use a 25k knob instead of 1k, the heating problem is solved, and it can detect a 3 cm coin at 30 cm. But the GEB is off and it also detects broken ceramics. When I turn on the GEB, the board’s sensitivity drops drastically. Overall, this circuit wasn’t what I expected and it can’t really work in the field.

[tuntunlin]

Greetings.

My GS5 Lite is now working well. The previous issue was due to the PCB not being a true two-layer board as per the original design, but rather a single-sided PCB layout, combined with a counterfeit NE5534 IC and insufficient grounding, as well as unnecessarily long trace paths. Now the problem has been resolved.


Instead of using the NE5534, I have substituted it with an LF351. I have applied offset adjustment to pins 1 and 5 of the LF351. I am using a 300µH coil with a 470Ω 5W damping resistor, and the waveform at pin 6 of the LF351 is correct.


I am currently testing the device. At a 10µs delay, the ground balance does not match properly; it only works correctly at a 23µs delay. The low-tone/high-tone discrimination is functioning correctly. However, what I need is the 10µs delay.


I have also tested with a 250µH coil, and the device still works correctly at the 23µs delay with proper ground balance and tone discrimination.


Frequency: 3 kHz
Pulse width: 100 µs


My current question is: what adjustments or changes are needed to make the device work properly at a 10µs delay?


Please kindly provide detailed technical information and support, respected teachers.

[daniel. z]

I'm amazed that a nearly registered geotech forum user with 17 posts asks so much. I wish you luck in making a TDI, first you wrote that you intend to make a TDI and in the next post you have neither a schematic nor a device that you can redesign. So again the old new member. Who is actually there to possibly get some data that is not available on the forum and that no one will even put as valid. All the best happy work.

Alright no need to be nervous upset.
I wish you success too.

[Orbit]

I'm amazed that a nearly registered geotech forum user with 17 posts asks so much. I wish you luck in making a TDI, first you wrote that you intend to make a TDI and in the next post you have neither a schematic nor a device that you can redesign. So again the old new member. Who is actually there to possibly get some data that is not available on the forum and that no one will even put as valid. All the best happy work.

[daniel. z]

Yes Proto TDI works very well! I did a TDI proto with a microcontroller instead of an analog timing part but according to the scheme given by Altra! Of course I also have an SL TDI. I actually have several versions similar to TDI and TDI proto But in the last two years I have made a perfect device that I can say is a dangerous beast with a lot of help from my friend Altra so I have used TDI sparingly. My favorites are the TDI _SL SD 2000 which is modified, compared to the original version the noise is reduced by 90 percent, the depth is increased, with an additional channel for discrimination! And the hybrid device GT or gold tax there were 6 - 7 different versions as I said terrible beast, it is an actual hybrid that works in the pi region and in the ib region at the same time! Which has dangerous depth and excellent discrimination. It was over 2 years of testing and a lot of work.. It works everywhere and nothing bothers it. Altra is a programming artist and a great friend of mine. My personal opinion is that GT is currently one of the best devices that combines the good features of ib and the excellent features of pi bipolar devices.

This is very good. I'm really amazed by your progress.
Do you have a test video of it?"

[tuntunlin]

Hello. First, set the gain volume to maximum and turn off the GB volume. Adjust the threshold volume so that you hear a low background sound. Set the potentiometer and frequency volume to the middle and set the offset potentiometer to zero. Then move a coin on the loop and slowly turn the delay volume until you reach maximum power.

I truly appreciate your kind guidance. I will give it my best effort.

[David222]

Dear fellow builders and mentors who have successfully constructed the GS5 Lite,
I would like to kindly request your help in answering this question.

On my GS5 Lite, I have already adjusted the NE5534 output to 0V DC and the waveform is now correct. The 4 sampling timing components have also been set accurately.

Based on my current tests, the detector only responds to a metal target up to a distance of about 8 cm.

Therefore, I would like to ask: are there any additional adjustments or specific balanced voltage reference points that I should check?

To be more specific, I am referring to the expected voltage values at the pins of ICs such as the TL072, TL064, and LT1114. Could you please advise what the proper voltages should be at those points?

My coil is 300µH, and the damping resistor is 470 ohms.

Thank you very much for your time and guidance.

Hello. First, set the gain volume to maximum and turn off the GB volume. Adjust the threshold volume so that you hear a low background sound. Set the potentiometer and frequency volume to the middle and set the offset potentiometer to zero. Then move a coin on the loop and slowly turn the delay volume until you reach maximum power.

[tuntunlin]

Change the damping resistor from 330 ohms to 660 ohms and check the results to see if any change occurs.
As Emerson would say, maybe the ICs are counterfeit.

Okay, I will do my best and give it a try.

[tuntunlin]

If you have a clear photo of your board with the ICs mounted and everything looks correct, it seems like you might be using a counterfeit IC.

Yes, I will go ahead and check/replace my ICs (in case they are counterfeit/faulty), and I will come back with the PCB layout and waveform results.
Thank you very much for your guidance and support.

[Orbit]

Yes Proto TDI works very well! I did a TDI proto with a microcontroller instead of an analog timing part but according to the scheme given by Altra! Of course I also have an SL TDI. I actually have several versions similar to TDI and TDI proto But in the last two years I have made a perfect device that I can say is a dangerous beast with a lot of help from my friend Altra so I have used TDI sparingly. My favorites are the TDI _SL SD 2000 which is modified, compared to the original version the noise is reduced by 90 percent, the depth is increased, with an additional channel for discrimination! And the hybrid device GT or gold tax there were 6 - 7 different versions as I said terrible beast, it is an actual hybrid that works in the pi region and in the ib region at the same time! Which has dangerous depth and excellent discrimination. It was over 2 years of testing and a lot of work.. It works everywhere and nothing bothers it. Altra is a programming artist and a great friend of mine. My personal opinion is that GT is currently one of the best devices that combines the good features of ib and the excellent features of pi bipolar devices.

[daniel. z]

8

I think it's worth it, but only in places where there are a lot of minerals in the ground, so it's not for every day. For certain places it is ok. Not too deep I did an 8 inch coil. And I have the original coil of gs 5. The Sl is perfectly silent at maximum sensitivity and can find coins under nails and debris where all possible vlf devices can absolutely not match it.Otherwise the proto TDI scheme is completely correct as put by Altra! TDI or Proto TDI is a bit deeper but also more noisy!

So, does the TDI Proto design work perfectly? Do you have the SL design yourself?
I wanted to buy a TDI SL and start reverse engineering the circuit from it, but unfortunately I couldn't find one.

[Orbit]

8

That's great, good luck.
I've decided to build it
do you think it's worth doing?

I think it's worth it, but only in places where there are a lot of minerals in the ground, so it's not for every day. For certain places it is ok. Not too deep I did an 8 inch coil. And I have the original coil of gs 5. The Sl is perfectly silent at maximum sensitivity and can find coins under nails and debris where all possible vlf devices can absolutely not match it.Otherwise the proto TDI scheme is completely correct as put by Altra! TDI or Proto TDI is a bit deeper but also more noisy!

[daniel. z]

Not with a friend. After that I repaired the pcb because without modification the gnd was unstable. The excess drawing was thrown out which is not used at all. Karl helped me with the voltage drop.

That's great, good luck.
I've decided to build it
do you think it's worth doing?

[Orbit]

Јеси ли сам урадио реверзни инжењеринг?

Not with a friend. After that I repaired the pcb because without modification the gnd was unstable. The excess drawing was thrown out which is not used at all. Karl helped me with the voltage drop.