Why does the Simplex+ pickup coke?

Discussion of the Nokta Makro Simplex metal detector here only.
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TinDigger
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Why does the Simplex+ pickup coke?

Post by TinDigger »

Out in the field yesterday and the simplex went off on a couple of occasions that confused me a little as my quest x p.i pointer couldnt locate. It was only by passing clumps of earth over the detector coil that I eventually found what it was. It basically looks like coal but I guess it is coke. Why does it trip the detector, it doesn’t seem to have any metal content from what I can work out?



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Re: Why does the Simplex+ pickup coke?

Post by Blackadder43 »

Coke has Carbon in it which is conductive, hence the signals ::g

https://en.wikipedia.org/wiki/Coke_(fuel)
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Re: Why does the Simplex+ pickup coke?

Post by sweepstick47 »

This is something which newcomers to the hobby often get confused about. Have a look at the link below which explains the process which causes coke to respond positively to most
TR/IB (Transmit/Receive/Inductance Balance) machines. ::g Regards ss47

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Re: Why does the Simplex+ pickup coke?

Post by Moruglah »

Give it time and you’ll learn the tone.
SIMPLEX +

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Re: Why does the Simplex+ pickup coke?

Post by JBM »

Moruglah wrote:
Sat Feb 08, 2020 7:21 pm
Give it time and you’ll learn the tone.

Also the screen readout. ;)

Happy Hunting,

Jerry.

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Re: Why does the Simplex+ pickup coke?

Post by Moruglah »

JBM wrote:
Sat Feb 08, 2020 7:33 pm
Moruglah wrote:
Sat Feb 08, 2020 7:21 pm
Give it time and you’ll learn the tone.

Also the screen readout. ;)

Happy Hunting,

Jerry.
That’s the second go to.
Coke gives a high screech in park.
In field mode coke has a kind of a fizz to the end of the signal.
If that makes sense.
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Re: Why does the Simplex+ pickup coke?

Post by Koala »

small, large, flat, round, burnt, damp, dry. Response from way negative to way positive.

With a single frequency machine its impossible to dig some. Although with experience its possible to ignore a lot of the signals

large faint signals. sounds different when swinging over from a different directions. On ploughed a quick scrap of the surface with your foot spots most without digging


multi frequency machines normally don't dig if any.


I was detecting a field that had been used for a ploughing competition. The surface was covered with the emptied out fireboxes. The masking effect meant depth was down to only the top few inches.

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Re: Why does the Simplex+ pickup coke?

Post by TinDigger »

Ah, so it’s capacitive rather than conductive. That may explain why the pinpointer can’t see it at all.

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Re: Why does the Simplex+ pickup coke?

Post by sweepstick47 »

TinDigger wrote:
Mon Feb 10, 2020 11:09 am
Ah, so it’s capacitive rather than conductive. That may explain why the pinpointer can’t see it at all.
I think it depends to some extent which Pin-Pointer you are using as some operate on the Pulse Induction principle which is largely impervious to the effects of capacitive induced target responses. Presumably, the transmitted field from a TR/IB pin-pointer, would also have to be of sufficient strength (in range) to energise coke to produce a response. Regards ss47
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Re: Why does the Simplex+ pickup coke?

Post by TinDigger »

Yes, it is indeed a pulse induction pointer I have. So that would explain it.

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Re: Why does the Simplex+ pickup coke?

Post by Koala »

the more sparky you run your machine the more shallow coke you will dig.


If time is short it might be worth turning the sensitivity down a notch

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Re: Why does the Simplex+ pickup coke?

Post by TinDigger »

Good tip. I found on the Simplex that ramping the sensitivity upto max in field mode and then setting the freq to F3 gave it incredible depth with hardly any chatter. I mean, it was picking up .22 airgun pellets at about 6" down!

Maybe I should dial it back a bit. [:)

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