Dual Field Pi Coils

[6666]

The file in post #56 is no longer there.

[Rov]

Hi,the Pulsematecoils variant,is 12 1/4inch outer winding size,they called "Double Field" not dual field to end name confusion with whites terminology.the windings have a pcb internally,whites do not.The detector ,whatever PI unit used sees 300uh at the coil plug total in a mono wired 5 pin plug and 1.1ohm total coils resistance.All in the ballpark for most Pi detector use easily.
Yes Fishers also have prior art patent ideas on so called dual field coils not just whites.always a work in progress for all to improve on and develop further I think.
I just quietly work away at whatever I think can give my machines that extra bit of Zing! in coil sensitivity,depth,and quietness where I can.an these have worked well for me.thanks.

[golfnut]

sorted list of whites patents here

http://www.google.com/search?tbo=p&t...onics,+Inc.%22

[6666]

Is this it ?

Patent Number: 7994789

[Reg]

Here is a link that will allow you to view the DF coil patent.

http://www.patentfish.com/search.php

Just enter dual field metal detector coil and look for the proper patent.

Reg

[6666]

Whats the dia of your 300uH DF coil ?

[Rov]

Hi ,D field coils for Minelabs PI,and Pulsemate detectors Australia.been done and dusted for some time now.Suit Whites TDI trialed and tested also,Good!
basic spec. 300uh total coil inductance both loop,an 1.2ohm total twin loop resistance.Mag.Mylar and Graphite screening to loops and shells internal.Cant say more,commercialisation in place for production and manufacture.Pulsematecoils.
Have a good day!Rov

[Dr Vel]

Maybe I breezed past it but I don't see where Carl ever posted the patent. Also is it just my imagination that the idea is possible, or has anyone talked about dual TX, RX coils on two frequencies as being able to give depth information? If so sorry I just cannot carefully read every post on this site in the very large number of pages. The idea just seems to me to be a logical extension of theory.

[6666]

Aziz, really nice visualisations!
I was just wondering if its not too much work for you
would you mind showing me what a dual rectangular coil 10inch by 6 inch on the outside
and 5 inch by 3 inch on the inside would look like if its possible please.

thanks
6666

[mikebg]

MORE MODERN NAME!
The "Dual field" name is no more modern!
MULTIFIELD SEARCH COIL or MFXC is the new name of an well known type winding. Each turn of wire creates its own field with different loop diameter.
There is variant with two windings (separate TX and RX) placed in induction balance.
http://www.geotech1.com/forums/showt...eferrerid=2910
The Multifield search coil can be made extremely thin (h=3mm only), which is ideal for underwater movement.
The abbreviation of modern name is MFXC. (XC means that the multifield coil is unknown for the customer :-)

[Sean_Goddard]

Uses magic words "Dual Field" sells this as the extraordinary novelty. Because people wish novelties, buy this willingly. Amen
Mrand

EXACTLY!!

From my experience 90% of detectorists are gullible souls who are sucked in by the latest "pseudo science" which manufacturers continually invent to sell their toys.

You could tell them a new machine has a "spendificating quanglesnarb" on it (or how about "optical target processor" - or LED for short) and they would go out and buy it if they THOUGHT it would give them more finds. BUT.......Speaking from experience, 99% of good finds I have seen have been made by people who "believe" in their machines, and if that made up term inspires confidence, who is to say that machine isn't therefor "better" than the previous model with EXACTLY the SAME electronics but in a new shiny case (Cough...cough..Tesoro...Cough...cough)?

Personally I think a fool and his money are soon parted. That's is my experience from 35 years of detecting and attending rallies!...Glad to see the people on here don't fall into ANY of those categories!

[6666]

Thanks all for this very interesting thread

[Aziz]

Hi Ian,

your coil is looking great. I like it.
Looking forward to see the finished version.

Aziz

[IBGold]

Hi Aziz and all here is one of my latest 18" Duel-Field coils prior to closing up the housing this is shielded and bonded into the top of the housing.
Regards, Ian.

[Aziz]

Aziz, some folks have made this coil many many years ago, but we did not know then that the coil name is 'dual field'

Hi kt315,

good job. A well done craftsmanship.

You could make the coil much bigger. It would go much deeper and it would still be sensitive to small targets.

Aziz