Surface blanker circuit

[turtlebowl]

Anyone have a surface blanker schematic?? OR circuit drawing of a detector that uses one?? I need another winter project. Phil

[porkluvr]

Anyone have a surface blanker schematic?? OR circuit drawing of a detector that uses one?? I need another winter project. Phil

Tesoro Royal Sabre?

[turtlebowl]

THANKS!! Looks great... any others out there?

Thanks, big help and a nice drawing! Now to figure out how to isolate the circuit for use on other detectors. Anyhelp would be appreciated. Also curious to know if this is the same circuit the other manufactures are using. Anyone know??

[pebe]

Anyone have a surface blanker schematic?? OR circuit drawing of a detector that uses one?? I need another winter project. Phil

What's a surface blanker?

[Carl-NC]

What's a surface blanker?

Shallow targets (less than, say, 3 inches) get ignored, or "blanked out." Can help reduce annoying clad.

[Geo]

Shallow targets (less than, say, 3 inches) get ignored, or "blanked out." Can help reduce annoying clad.

Can you explain more about the redusing of annoying clad!!! I don't understand anything

Regards

[turtlebowl]

Blanking circuit

"The clad" carl is refering to is Clad ....as in new/modern coins. i.e. shallow.

[Geo]

"The clad" carl is refering to is Clad ....as in new/modern coins. i.e. shallow.

Thank you

[willy]

Another overlooked/little known use of the surface blanking circuit is to eliminate (for the most part) large targets. By having the depth set to the minimum and slightly elevating the coil, one can pick up surface and deeper coin sized targets while knocking out cans and many other large items. ..Willy.

[porkluvr]

Thanks, big help and a nice drawing! Now to figure out how to isolate the circuit for use on other detectors. Anyhelp would be appreciated. Also curious to know if this is the same circuit the other manufactures are using. Anyone know??

If you have trouble isolating the Royal Sabre's surface blanking circuit, look at the schematic for the Gold Mountain King Cobra... almost exactly the same, but no surface blanking.

http://www.geotech1.com/forums/showt...obra#post82738

Just for info, another comparison is to the Golden Sabre, of course. It's here, somewhere.

[pebe]

Can someone tell me how the circuit of a 'surface blanker' works?

[porkluvr]

Can someone tell me how the circuit of a 'surface blanker' works?

In a nutshell, before you use SB mode you might assume that your top ground surface has junk (including low value recently minted coin) targets which will give strong returns, and that more valuable older coins are deeper and will give weaker return signals.

When SB mode is selected, target signals that are stronger than a user selected threshold are subtracted from the detection process.

[pebe]

In a nutshell, before you use SB mode you might assume that your top ground surface has junk (including low value recently minted coin) targets which will give strong returns, and that more valuable older coins are deeper and will give weaker return signals.

When SB mode is selected, target signals that are stronger than a user selected threshold are subtracted from the detection process.

Many thanks for the explanation.

[turtlebowl]

Thanks Porkluver

Meant to mention before now a big thanks for the King Cobra drawing. It is very helpful when compared to the TRS circuit drawing.
I am getting much closer to understanding the very basics of a discriminating detector.... with the help of all the excellent people here. And that's really what it is about for me... I've always been a tinkerer and have played with circuits for 30 years. Learnig just a tad at a time. Facinating stuff to me.
I HAVE a small bit yet I am stumbling over. Hope someone can clarify///// The Golden Saber Light has one Discriminate channel and one All metal Channel ?? In other words the T Gold Sabre has two identical parellel circuits with filter networks in each. Is this then a two filter discriminator?? (I realise a detector needs 1-Disc & 1-AM summed to operate, thats not the question) Other detectors -like the Royal saber- have 2-3 identical Discriminate Channels besides the All Metal Channel. Isthis 2-3-4filter circuits??
Also is the Binary counter/ divider Chip 4024 solely to set the Audio Tone/ID on the Gold Sabre ? or is there another function?