BARACUDA-Legend-1

[Old cart]

I use 2x 9v battery in pararel, now im using 8x AA 1.5v to get 12v.
My board doesnt have 47uf and 10uf polarity caps, the big one is 6800uf, in that scheme is 4700uf, its very different with ver.2

does it work any better with the 8 AA BATTERIES? The 9 v batteries in parallel while clever, are not a good source of power.
Look at the scheme I sent you. You will notice caps from - to + 5 volts. In general that is not the best way to do it. Try to make yours more like the scheme shown. Note that if you change it too any times if may break so be very careful.
The 4700uF should be fine. Focus on getting C7,8,9 and 10 connected correctly. This may require you to solder the caps to the back of the board.
The cap connected between the + and- inputs before the regulators should be removed.
Good luck.

[ripsdevala]

I use 2x 9v battery in pararel, now im using 8x AA 1.5v to get 12v.
My board doesnt have 47uf and 10uf polarity caps, the big one is 6800uf, in that scheme is 4700uf, its very different with ver.2

[Old cart]

Yes, 5534 pin 5 is 0, +5 and -5 is normal, already clean the flux with copper brush (very effective). Let me check again...
Will change the battery, for now is 7.5+volt

Yes 7.5 volt is too low. What kind of battery are you using? Copper brush is not the best for such use. Make sure no metal remains on the board with a magnifier.

You need to measure pin 6 of the 5534 for offset voltage.

This is the most current schematic, but it is stil not final. Check the caps around the power supply they have been changed.

http://www.geotech1.com/forums/attachment.php?attachmentid=35888&d=1460301639

If it is still beeping near the ends of the swing it sounds like an earth field problem. This is hard to adjust without the scope. You can test with a small ferrite magnet or a plastic refrigerator magnet.
Very clear pictures taken in good light of the whole setup, a close up of the top of the board and the bottom may help too.

[ripsdevala]

Yes, 5534 pin 5 is 0, +5 and -5 is normal, already clean the flux with copper brush (very effective). Let me check again...
Will change the battery, for now is 7.5+volt

[Old cart]

Progress...
3 40106 have arrive, put it on.... nothing change


I use schematic from sticky thread, not the one with 22uf capacitor extra (kt13 version).

What is it preciuos.....

Sorry to hear this. If you want to work on it some more you will need a scope and maybe a digital multimeter. For now about all you can do is examine all the solder joints carefully and make sure they look clean and shiny. Have you cleaned the board yet with alcohol and an old toothbrush until it looks clean? Have you adjusted the voltage on the output pin of the 5534 to 0 volts? What do the -/+ 5 volt supplies read? All voltages should be measured relative to the battery - terminal.

[ripsdevala]

Progress...
3 40106 have arrive, put it on.... nothing change


I use schematic from sticky thread, not the one with 22uf capacitor extra (kt13 version).

What is it preciuos.....

[ripsdevala]

I built on of those. Very useful. Can run of battery so also great for testing sensors on a car.

Has limitations. Only one channel and maximum of 50v

There are two versions one has some surface mount like the one in your photos (and I built) which is slightly more difficult to build.

Mine has a slight software glitch. When you switch it on the voltage readings are wrong. If I adjust the time base down one then back up it reads perfect. Frequency measurement is spot on.

There is firmware upgrade when i google, maybe can inprove the reading

@old chart leme do some research...

[Old cart]

Im from Indonesia, first time I want to buy a manufactured MD from UK but the tax is too high, my goverment even put a high restriction on that one.
A real scope is to much for me, the chepest used one is about $200, im barely create my first board few weak ago, create BFO, PIRAT and simple pi, but not satisfied me, this bara is very promising, i know very basic electronics work, just soldering, change broken part and as such, im an IT based infrastructure.

The scope what im talking about is this one:






Vertical
Number of Channel: 1
Analog Bandwidth: 0 - 200KHz
Sensitivity: 10mV/Div - 5V/Div
Sensitivity error: < 5%
Resolution: 12-bit
Input Impedance: 1M ohm
Maximum Input voltage: 50Vpk
Coupling: DC, AC, GND

Horizontal
Max Real-time Sampling Rate: 1Msps
Timebase: 10us/Div - 500s/Div
Record Length: 1024

Trigger
Trigger Modes: Auto, Normal, Single
Trigger Types: Rising/falling edge
Trigger Position: 1/2 of buffer size fixed

Display
2.4-inch color TFT LCD with 320 x 240 resolution

Power Supply
9V DC (8 - 12V acceptable)
Supply Current: 120mA

I do not recommend that model. It has very limited functionality for this use the bandwidth is only 200Khz which is too low and it has only a single channel which wil not allow you to compare the timing between two signals. This requires two channels to do easily.
One last limitation is that it is limited to only 50 volts which is easily exceeded by many PI detectors.
Keep looking and see if you can find one that is:
at least 1 MHz bandwidth
at least 2 channels
can tolerate at least 200 volts

this one would be a little better, it is made by the same manufacturer.

http://www.jyetech.com/Products/LcdScope/e112.php

It has more bandwidth, lower noise, still is only one channel but has external triggers so you can measure between two channels, and does have a case.

[Koala]

I built on of those. Very useful. Can run of battery so also great for testing sensors on a car.

Has limitations. Only one channel and maximum of 50v

There are two versions one has some surface mount like the one in your photos (and I built) which is slightly more difficult to build.

Mine has a slight software glitch. When you switch it on the voltage readings are wrong. If I adjust the time base down one then back up it reads perfect. Frequency measurement is spot on.

[ripsdevala]

Im from Indonesia, first time I want to buy a manufactured MD from UK but the tax is too high, my goverment even put a high restriction on that one.
A real scope is to much for me, the chepest used one is about $200, im barely create my first board few weak ago, create BFO, PIRAT and simple pi, but not satisfied me, this bara is very promising, i know very basic electronics work, just soldering, change broken part and as such, im an IT based infrastructure.

The scope what im talking about is this one:






Vertical
Number of Channel: 1
Analog Bandwidth: 0 - 200KHz
Sensitivity: 10mV/Div - 5V/Div
Sensitivity error: < 5%
Resolution: 12-bit
Input Impedance: 1M ohm
Maximum Input voltage: 50Vpk
Coupling: DC, AC, GND

Horizontal
Max Real-time Sampling Rate: 1Msps
Timebase: 10us/Div - 500s/Div
Record Length: 1024

Trigger
Trigger Modes: Auto, Normal, Single
Trigger Types: Rising/falling edge
Trigger Position: 1/2 of buffer size fixed

Display
2.4-inch color TFT LCD with 320 x 240 resolution

Power Supply
9V DC (8 - 12V acceptable)
Supply Current: 120mA

[Old cart]

Ya.. R19 15k, typo.
Maybe just my imagination to feel the magnetic earth increase the deeper, too much nail in my front yard, the LF412cn just arrive, put on it... but i don't know, look like same to me, no substitute part except resistor (mix 1/4, 1/2 watt) and mps102.
I think i need to buy this scope tool, most member use it here, small diy kit china would be enough right?

If you have lots of nails then testing will be a problem. it is best to find a section of ground where there is no metal then plant test targets.
An oscilloscope is very handy but you have to learn how to use it. I have never used any of the cheap Chinese scopes so I can not comment other than to say they may cause more confusion than they solve:<)
It depends on how much you are willing to spend and how much you want to learn about electronics. If you are wanting to learn how all this works and have the time a scope is a good investment.
Where are you located? It may be possible to buy a scope locally.

[ripsdevala]

Ya.. R19 15k, typo.
Maybe just my imagination to feel the magnetic earth increase the deeper, too much nail in my front yard, the LF412cn just arrive, put on it... but i dont know, look like same to me, no subtitute part except resistor (mix 1/4, 1/2 watt) and mps102.
I think i need to buy this scope tool, most member use it here, small diy kit china would be enough right?

[Old cart]

Change R18=12K, R18=15K right?
Reduce tilt beep, already test outside....Nice, hope new 40106 will arrive tomorrow.

I using HCF40106, CD40106 is too sensitive.
Is this MD use ground earth efect as signal gain, its detect small nail on the ground, not in the air.

Dig site [ATTACH]36369[/ATTACH]
Result [ATTACH]36370[/ATTACH]

Your R 18 should be 12K
YOUR R19 should be 15K
Your R17 should be 150K and should not require changing

Idealy you could use an oscilloscope to adjust R18 or R19 slightly to optimize earth magnetic field rejection but since you do not have one this will have to do.

Replacing the 40106 MAY help with with this proble.

I do not understand what you mean in your last sentence.

[ripsdevala]

Change R18=12K, R18=15K right?
Reduce tilt beep, already test outside....Nice, hope new 40106 will arrive tomorrow.

I using HCF40106, CD40106 is too sensitive.
Is this MD use ground earth efect as signal gain, its detect small nail on the ground, not in the air.

Dig site
Result

[ripsdevala]

Ahaa.... let me work this.

Thanks