Magnum on steroids!

[bandito]

http://www.geotech1.com/forums/attachment.php?attachmentid=36787&d=1469989775

These boards are correct,but the file that is shared here is obviously wrong

[chevesne]

He says that, I suppose.

http://www.geotech1.com/forums/showt...680#post219680

It only happens to those who undertake.

[Artyom]

Sven,
Get a chip for SMD mounting and lay it at the place it on the board. You know that the first pin is always the top left. If the first pin of IC match marked with a white dot on the board first pin it means that you have no problem. If there is a discrepancy and white point is on the other side of the IC it means that there is a problem. Then the only solution is to solder IC lying on his back to have matching pins. There is another solution - order a new PCB but this time with proper placement of ICs.
I looked boards of ivkonic and I can say that he has turned layers of the PCB. Green layer, shown as C2, really should be a layer C1 /standing on top of the board and/ vice versa C1 blue layer should be a layer C2 /standing bottom the board/.

IVCONIC what do you say about the mirror image of your PCB?

[Toros]

Guess it depends upon the way you view it.

[ATTACH]37970[/ATTACH]
[ATTACH]37971[/ATTACH]

Sven,
Get a chip for SMD mounting and lay it at the place it on the board. You know that the first pin is always the top left. If the first pin of IC match marked with a white dot on the board first pin it means that you have no problem. If there is a discrepancy and white point is on the other side of the IC it means that there is a problem. Then the only solution is to solder IC lying on his back to have matching pins. There is another solution - order a new PCB but this time with proper placement of ICs.
I looked boards of ivkonic and I can say that he has turned layers of the PCB. Green layer, shown as C2, really should be a layer C1 /standing on top of the board and/ vice versa C1 blue layer should be a layer C2 /standing bottom the board/.

[SVEN1]

Guess it depends upon the way you view it.

[bandito]

I don't understand what you are saying

How will soldered,see the layout of the integral PCB and datasheet

[Toros]

I don't understand what you are saying

Sven,
Look at the pictures. Each integrated circuit has marked the first leg - white point sufficiently noticeable. The photos can be seen that the point is placed on the left of the integrated circuit. But first pin is right. This means that if the photos are 1: 1 with your boards then you will have to solder chips lying on it's back and bend their legs to touch to the board.
Do you understand now?

[Toros]

Maybe the photos are mirror-reversed!

[SVEN1]

I don't understand what you are saying

[bandito]

These boards I think are wrong

Look integrated circuits are mirror,and can not be soldered,see first pin where ,,,,the layers are wrong

[SVEN1]

Why?
Ivonic had choice of 3 boards you can use.

I made "mag_redu_pcb" version, which is SMT (Surface Mounting Technology) or SMD (Surface Mounting Device) version.
But unlike the "mag_compl_pcb" version; here at "mag_redu_pcb" version: i used 1206 sized SMD components.
I did that for one simple reason; to be able to solder them manually.
1206 sized SMD components are just about "human" enough to be manipulated and soldered by a common hobbyists.
For those with much better sight and more calmer nerves: the fist one; the "mag_compl_pcb" version will be also alright.

[bandito]

PCB's have arrived, now to hunt down some parts

These boards I think are wrong

[Gwil]

Since the detector operates at a frequency well away from the Rx LC resonance perhaps a better approach is to see the reactance of the capacitor cancelling out some of the coil reactance, which improves the input signal (current). In that sense you could say it's "untuned".

[Gwil]

It's true that Andy Flind believed the coil was "untuned". From the original article:
　
"TR2 is the received signal preamp and is connected as a common base amplifier. This and oscillator TR1 are both based on designs which have been used in several manufactured machines because they are simple and work well. The receive coil L2 is untuned; this, coupled with the low impedance input load of TR2 ensures the predictable phase response required for reliable discrimination."
　
The fact that the Rx was based on existing designs may be significant. I'm wondering if AF saw there was no capacitor across the coil in these designs and assumed it was untuned, not realising that the capacitor connecting it to the emitter formed a series resonant circuit (note that its value is unusually small for just a coupling capacitor - its reactance at 15kHz is 226 ohms). I make its resonant frequency about 7.4kHz, compared to the Tx freq of 15kHz.
　
Of course I could be wrong but when I see an inductor and capacitor in series I see a series resonant circuit until it's shown not to be.

[ivconic]

Again, interesting. The Rx may not be tuned to the Tx frequency but I'm pretty sure the Rx coil and C1 form a series resonant circuit. If the coil inductance was 5mH the input current would peak at a little above 10kHz.
If I've got this wrong I hope someone will explain how. (it's been a long time since I studied AC theory)

Actually is all there in Andy Flind's "Magnum" article.
I guess you can find it here on forum somewhere.