ARADO 120 SCH& PCB

[daluka]

This quote from Andreas #30
you must build a electronic-cap

HAS ANYBODY A SCHEMATIC FOR ELECTRONIC-CAP PLS?

What is it?

[Pete61]

What is it?

Like this



but controlled by DC voltage, not your fingers.

https://www.usefulcomponents.com/mai...iable_cap.html

[daluka]

Like this



but controlled by DC voltage, not your fingers.

https://www.usefulcomponents.com/mai...iable_cap.html

Variable Capacitor

[Toros]

Hi all
All you have heard for "Myth " arado120.
I make this two years ago, with fine results and new design PCB . This machine has voice for all metals and Ameter for discrimination. With this method, we can heard a detection target and with eyes, we can see dicrimination
Here is sch diagram without errors and full analytical PCB (101,60mm X 81,28mm) without errors too. The next post i publish infos for (how make Tx-Rx coil). My machine work with O-O coils 20cm diametre and detect a euro 36cm distance on air, a box 20cm X 20CM 95cm distance on air . Maybe with D-D coil is better... we want try for this. In practice never i use, only inside laboratory. Easy make PCB, with easy coils and difficult calibration "null".
I don't answer questions, why I believe this is very analytical, only you want make PCB.. put parts and finish
In next post I will present photo's, Method of calculations coilsand method calibration "null"
I wish good success
best regards
Andreas

Can you post the files in "Express pcb" format. In PDF format I can't edit the board trace.

[aft_72005]

Can you post the files in "Express pcb" format. In PDF format I can't edit the board trace.

Andreas has not been here for a long time.

[Toros]

Andreas has not been here for a long time.

Apparently I'll have to redraw the board myself.

[Malospelos]

Good morning colleagues, yesterday I received an original Arado 120B, after maintenance, I have brought it back to life, everything works, it came with an original coil, the only thing is what depth should I put?
It has an 8" coil and accepts a 1 euro coin at approximately 25 cm.
I would like to know if making a coil could increase or improve the performance. I have heard that it was very deep, but it doesn't seem that way to me, I don't know if it should be tuned, part of the board comes with Epoxy so you can't see the components.

I also wanted to ask if it is possible to set a Ground Balance.

[GeoMax]

Just in case if someone is interested....

I see a Classic Arado 120B with meter discriminating metal detector currently offered on eBay UK.
Here is the link https://www.ebay.co.uk/itm/126670959733?

[daluka]

Patent 4096432, Arado Electronics, Paul Anthony Spencer

[kt315]

daluka

Geotech Metal Detectors - Patents (geotech1.com)

[ivconic]

In 1987 when I was 21, I went to London and bought my first detector.
That was the Arado 120 you are talking about here.
I used it until 1991/2 when I sold it and bought a White's Eagle IIc.
Ah... the good old days! Brings back so many memories!

[daluka]

History of Arado since 1975.

[Carl-NC]

I didn't know that had so many models. I've only heard of the 120(B), which I have one.