IDX-PRO+VDI

[Jerry]

I bulit the IDX Quicksilver copy concentric oil with mixed results Very good for ferric down to about 2' , but crappy on coins. I am going back to DD , which i s more predicable.

That sure sounds like good material for a project if you are willing to post some information on construction details, etc. Looks like there may be some potential.

It would be interesting to see if others get the same results or are able to make it work.

Jerry

[Wiltran]

I bulit the IDX Quicksilver copy concentric oil with mixed results Very good for ferric down to about 2' , but crappy on coins. I am going back to DD , which i s more predicable.

[ivconic]

Like i mentioned earlier; it should work in range 6.35 to 6.95 kHz.
At some versions there is also feature to adjust freq. (trimmer and few components, inside).
Here too, with P4 you can pull freq a bit if needed...

[Jose]

Thanks Wiltran
I'm playing with different values of capacity, RX and TX.
Apparently, the RX coil must sintonizarce in resonance with the frequency of TX.
With the values for coil construction home, you get the best results.
A coin is detected more than 35 cm at the table of the workshop, but they are the first tests.

A Cordial Welcome
Jose

[Wiltran]

Hello Forum
I finished building the IDX-PRO, homemade roll.
The TX range seems low, 11 volts peak to peak.
The frequency is 5875 Hz
What are the correct values?
thanks
Jose

Jose, my TX freq. is in the 6.5KHZ range.

[Jose]

Hello Forum
I finished building the IDX-PRO, homemade roll.
The TX range seems low, 11 volts peak to peak.
The frequency is 5875 Hz
What are the correct values?
thanks
Jose

[hugo]

New Kit

Maybe, We will see the IDX-PRO & VDI into Silverdog's shop very soon ?

[Fabian]

Thanks

Thanks Ivconic. I have all the components. Next week I will begin to build it.

[ivconic]

Hello everyone. My name is Fabian and I'm from Argentina. I´m following the Geotech forums from two years ago (more or less). I have little previous experience in electronics, except that my father was a manufacturer of televisions and radios in the late '60s in a small factory he owned and electronics always was in the air in my house. After that, I built some small stuff like speed controls for my workshop motors, or small FM transmitters to use as "baby call" for my children.
Some time ago, I started with MD's projects designed by the Rev. Thomas Scarborough (I know, I know, he is not beloved here, but it was a good start for a beginner, and work very well, despite be very simple!) and became a passionate hobby for me. Then I made one Baracuda and one TGS with good results.

This is my first post in the forums, because even here, I can found the answers for my questions reading the posts of each threads and I think that I haven´t got enough experience to share wiht you, for the time being, I´m learning. Take this opportunity to thank all who contribute to interesting projects that are presented here.

Well, after my introduction, here's the questions:

I am following this thread from the beginning with great interest and as happens to Ivconic I can not find MCP integraded line in my country, then: Can I use the IDX only by the sound until I get the CI's? Would it work like any other old MD? Or the VDI is essential?

Thanks in advance

Fabian

Yes you can. IDX will work without VDI and will indicate detection with audio.

[ivconic]

Ivconic, what did you use for a faraday shield on this homemade quicksilver coil? How do you shield the RX and feedback coil?

I used graphite spray and applied it on the bottom cover of coil.

[Fabian]

Questions about VDI

Hello everyone. My name is Fabian and I'm from Argentina. I´m following the Geotech forums from two years ago (more or less). I have little previous experience in electronics, except that my father was a manufacturer of televisions and radios in the late '60s in a small factory he owned and electronics always was in the air in my house. After that, I built some small stuff like speed controls for my workshop motors, or small FM transmitters to use as "baby call" for my children.
Some time ago, I started with MD's projects designed by the Rev. Thomas Scarborough (I know, I know, he is not beloved here, but it was a good start for a beginner, and work very well, despite be very simple!) and became a passionate hobby for me. Then I made one Baracuda and one TGS with good results.

This is my first post in the forums, because even here, I can found the answers for my questions reading the posts of each threads and I think that I haven´t got enough experience to share wiht you, for the time being, I´m learning. Take this opportunity to thank all who contribute to interesting projects that are presented here.

Well, after my introduction, here's the questions:

I am following this thread from the beginning with great interest and as happens to Ivconic I can not find MCP integraded line in my country, then: Can I use the IDX only by the sound until I get the CI's? Would it work like any other old MD? Or the VDI is essential?

Thanks in advance

Fabian

[Wiltran]

I wouldn't calculate nothing, because we already do know coil specs.
Few descent White's coils are already explained here on forum in the past.
Also there is complete rip off of White's coil done by Russian colleagues.
But, once in the past i didn't knew that. So i was pushed to make something on my own.
First coil i made for CL3 was complete wild guess - but worked fantastic!
I used coil former exactly the same as for Fisher's Quicksilver 27cm coil.
Concentric - not DD.
I made 31 turns for TX (can't exactly be sure about gauge, but think it was 0.5mm or so..),
11 turns for feedback (same wire) and 250 turns for elliptical RX, wire was 0.22mm.
Main "trick" was the tuning with proper capacitors (that's the point of whole story).
White's design, such as CL3 or IDX (call it anyway you want) is pretty tolerant on coil specs BUT ONLY if coil is tuned properly with capacitances.
White's CL3 specs says it can operate in range 6.35kHz to 6.95kHz, if i remembered it good.
Originally there is 1uF+ ~80nF parallel to 0.54mH TX coil, and 33nF parallel to 36mH RX coil, so calculation is easy than?

Ivconic, what did you use for a faraday shield on this homemade quicksilver coil? How do you shield the RX and feedback coil?

[ivconic]

Power consumption of the VDI is about 3.2 milliamps (without backlight, of course), which is not so much.
Approximately half of this consumption is LCD, I use type AC-162BYILY-H.
It minimizes power I used MCP1703 regulator instead of 78L05. Also MCP607 could be used instead MCP602.

That's my problem; i used 78L05 and also couldn't obtain MCP opamp.
That's why i have more power consumption.
Like i said; it is not problem at VDI but at IGSL which is "good customer" with components i had in my workshop when made it.
Also, i am using ordinary, common LCD, made in China, which can draw much more, especially with back light.

[holyuser]

Power consumption of the VDI is about 3.2 milliamps (without backlight, of course), which is not so much.
Approximately half of this consumption is LCD, I use type AC-162BYILY-H.
It minimizes power I used MCP1703 regulator instead of 78L05. Also MCP607 could be used instead MCP602.

[ivconic]

All the LCD based metal detectors i have seen so far are suffering from a bit higher power consumption.
Especially if back light is used.
That's the fact we have do deal with it.
Russian colleagues tried to overcome that by use of low power LCD's like the one from Nokia 3310 phones.
It is cute solution and only drawback can be the size of such LCD - it is to small.
In case IGSL+VDI problem is not in VDI but in IGSL, which is having a bit higher power consumption, some 60-70mA.
Ordinary "smart" LCD's , based on Hitachi chips are easy available to each one of us, but those are also not low power.
So, main goal here is to find a way to lower consumption as less as possible.
So... at the end, all we can do is to design detector which will be ultra low power....
Speaking of VDI... nothing more seriously we should resent to it, because it is only processing the outer signal.
Better signal from outer world - better results.
Worse signal - worse results.
It is up to detector and not up to VDI.