New Minelab Go Find Series Coil

[Bodhi3]

Dear friends,
Do someone could explain me what kind of coil is actually using the new Minelab Go Find series (20, 40, 60).
I still don't understand if it's a concentric, coplanar, monoloop (very strange for a VLF machine) or a weird DD.

Does anyone has made a little investigation on it?

Thanks in advance,
Leonardo/"Bodhi3"

[WM6]

There is nice Search utility on Geotech:

http://www.geotech1.com/forums/showt...inelab-GO-FIND

[Davor]

There is a possibility that a balancing coil is mounted (hidden) within a hinge which is quite bulky. It is doable. You could even put a ferrite screw to it to facilitate tuning.
But until someone puts it under x-ray everyone's guess is just as good.

[greylourie]

There was a video posted couple months ago. At around the 1 hr 2 min mark, there is a slight pause after the question is asked of Gary Schafer from Minelab. He states its a concentric coil, of "special" lightweight new design/tech from the company.

Video here: https://youtu.be/Ya-p0aCc6-0

I think its interesting to see the pricing, and feature set of this new series. Other manufacturers should prick their ears up.

[WM6]

So called 2 to 4 Find Modes are nothing else, than as little as 2 to 4 position Notch filters, renamed in "Find Modes".
Cheap marketing trick.
Such concentric coil design is one of worst design for pinpointing.
Construction is plastic fantastic.
So all is in accordance with its price - no big pricing surprise from Minelab.

What I praise is collapsible detector body construction.
Collapsibility is desirable design way addressed to all producer.

[crane]

The ML GoFind RX and TX coils are wound together and are thus fully coupled mechanically. The coils are nulled electronically. Other electronic nulling methods require a mechanical null to start with.

[greylourie]

Hi WM6, its an entry level machine. Seems to pinpoint nicely.

[WM6]

It is entry level device, yes, but for over 300 dollars (GoFind 60) we can expect exchangeable coils and at least 8 instead of only 4 notch positions (so called ML "Find Modes").

What could be example for other producers is collapsible design and having Volume (not having Volume control even in 800 dollars machines is a big flop of some other producers).

[Bodhi3]

Thanks everybody...

[bernte_one]

the first model of gf40 and 60 are tested by users here in germany- the first Impression are really bad
arm Cup too small, for normal adult
thin plastic
stem is not solid as you would expect it from ML
cant really fix the postion of the lower stem part
the revory time is so slow like you can see in the Videos - it is not a failure in Video converting this is real
depth- omg
pinpointing - a reason to use a pinpointer
user Panel - also a bit thin, if you press a button the Panel Flex not less

just a short info
first Dealers said you cant sell it as it is- would be a bad buisness if every second unit returns

[Carl-NC]

The ML GoFind RX and TX coils are wound together and are thus fully coupled mechanically. The coils are nulled electronically. Other electronic nulling methods require a mechanical null to start with.

I would have guessed that the TX & RX coils have a little gap between them, which is why the plastic is rather wide. Tightly coupling the TX/RX coils kills target sensitivity. BTW, back in the 80's-90's White's made a detector with an un-nulled TX/RX concentric coil. It was the "Treasure Master," a name they re-re-recycled last week.

[Bodhi3]

What about these patents from Minelab?
http://www.pat2pdf.org/patents/pat20110234214.pdf
http://www.pat2pdf.org/patents/pat20130057286.pdf

[crane]

The relevant patent....


http://www.pat2pdf.org/patents/pat20140062488.pdf

[WM6]

One more patentomaniatic patent.
Such ferrite bead shielding of solder or connector joint from coil self detecting are old known prior art (at least to me if not for patent examiner).

And they are so smart that patent protected ferrite material (bead) shielding only and not solder joint shielding by using other means not declared as ferrite too and that can make solder joints invisible, like par example this:

http://kgs-ind.com/wp-content/upload...hrink-Tube.pdf

Hey ML, don't update patent by EMI Heat Shrink Tubes - this post is prior art too. As wel as liquid EMI coating made out of Non-Ferrite material with adequate permeability.

[crane]

One more patentomaniatic patent.
Such ferrite bead shielding of solder or connector joint from coil self detecting are old known prior art (at least to me if not for patent examiner).

And they are so smart that patent protected ferrite material (bead) shielding only and not solder joint shielding by using other means not declared as ferrite too and that can make solder joints invisible, like par example this:

http://kgs-ind.com/wp-content/upload...hrink-Tube.pdf

Hey ML, don't update patent by EMI Heat Shrink Tubes - this post is prior art too. As wel as liquid EMI coating made out of Non-Ferrite material with adequate permeability.

The ferrite bead patent has been discussed here before and the highly conductive heat shrink tubing in your link wouldn't do anything to cure the problem the beads address.

Do you understand why the solder dags can cause apparent false ground noises? Why they can give a signal even though they don't move relative to the coil?