field test unit no 001 "model T"

[PATCHES JUNIOR]

Hey, what a luck. I obviously have already implemented the Moodz spider coil type. Hmmmmm, no additional coding required...

^sif,
getting rich and a "Minelab" share holder soon... *LOL*

How do you "code" a coil? I think you need to take more pills and buy a new pair of running shoes!!! And as duggy says "the onus is on you".

[Aziz]

How do you "code" a coil? I think you need to take more pills and buy a new pair of running shoes!!! And as duggy says "the onus is on you".

No, I meant the coil software of course.
A coil is modelled via its design parameters.

No, "the onus is on you and your mates".
I think, I should keep the results until I get paid for! *LOL*
Hey, you & your mates could start a "kickstarter" project to fund the results. *LOL*

^sif,
getting ultra-rich now!!! *LOL*

[clancy]

Spider web coil have
Lower Q at metal detector frequencies for same wire because it need more length for same inductance (more turn). Need more thick wire for same Q. Make coil heavy.

Less field concentration near winds because winds spread wide. Bad for detect very small nugget.

Inside wind less diameter than outside wind and deep detect depend approx. diam^4 for target few time deeper than coil diameter. Less average wind diameter bigger effect than more turn (need for same L), and this why deep advantage better for bundled coil.

[Aziz]

Surprise, surprise, big surprise!!!
"Free lunch" or not, that is the big question.
My betting office is open now. Your stakes please.
^sif,
getting ultra-ultimate-rich now! *LOL*

[Aziz]

Just finished. I have the 100% correct answer now.
MUHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA...
.
.
The correct answer is 42.12 of course! *LOL*
Cheers,
4212

PS: Your stakes please.

[Doug2]

Doug it is common knowledge in the metal detector manufacturing industry that they do not work as well as a bundled coil, or they would be using them. As Moodz has stated they are easy to build and cheap to produce. So if they were better, the companys would be using them. That is all the info that I and anyone else needs. So first it was Minelab you hated. Now it is bundle wound coils. What is next? Me? Woody? Big dogs? Global warming?

The industry only makes bundle wound coils because they are quick ,cheap and very easy to make and thus very highly profitable! The bundle coil parameters are also very easy to calculate and are easily reproducible and predictable compared to spider wound coils. "What is next? Me?" How can one hate the biggest fool on the web?

[PATCHES JUNIOR]

Me?" How can one hate the biggest fool on the web?

I guess you do not read other gold detector forums Doug.

[Doug2]

I guess you do not read other gold detector forums Doug.

Yes I do including "private" one's! LOL! But back to topic.What are your thoughts on an appropriate coil testing regime? eg I wonder what testing regime commercial coil makers use when testing a new coil?

[robby_h]

Spider web coil have
Lower Q at metal detector frequencies for same wire because it need more length for same inductance (more turn). Need more thick wire for same Q. Make coil heavy.

Less field concentration near winds because winds spread wide. Bad for detect very small nugget.

Inside wind less diameter than outside wind and deep detect depend approx. diam^4 for target few time deeper than coil diameter. Less average wind diameter bigger effect than more turn (need for same L), and this why deep advantage better for bundled coil.

As Clancy said, spider web coil have lower Q at metal detector frequencies for the same wire because it needs more length for the same inductance (more turns) and more turns to obtain the same inductance means lower Q (higher R) unless we use thicker wire, which then makes the coil heavier.

Less field concentration near the windings because they are spread out. This is bad for detecting very small nuggets.

There is a more significant difference between inner diameter and outer diameter. Lower average diameter has a larger effect than needing more turns for the same inductance.

One member here claims that a stock ML PI won't work with a coil Q over 3.9, how did you overcome this problem Doug?

Tell us the depth advantage you measured when testing the spider coil Doug. Was it similar to a smaller or larger bundle wound coil or didn't you do this comparison? Could we obtain this claimed depth advantage by other means such as increased voltage or gains, and you still haven't commented on the fact that the detector gains would have to be wound back because increased depth would also increase the ground signal?

You still haven't commented on the coil TC which would be very long if we increase Q. Is this finally an admission that Minelab got the coil TC right and you and the rest of the world got it wrong?

And regarding testing protocols, it's worth noting that you tested Enhance timings in ground suitable for Normal timings making the test completely meaningless. You now have the hide to ask PJ to help you test a coil??

It seems you have jumped in the deep end without your life jacket again Doug.

[Doug2]

As Clancy said, spider web coil have lower Q at metal detector frequencies for the same wire because it needs more length for the same inductance (more turns) and more turns to obtain the same inductance means lower Q (higher R) unless we use thicker wire, which then makes the coil heavier. Less field concentration near the windings because they are spread out. This is bad for detecting very small nuggets. There is a more significant difference between inner diameter and outer diameter. Lower average diameter has a larger effect than needing more turns for the same inductance. One member here claims that a stock ML PI won't work with a coil Q over 3.9, how did you overcome this problem Doug? Tell us the depth advantage you measured when testing the spider coil Doug. Was it similar to a smaller or larger bundle wound coil or didn't you do this comparison? Could we obtain this claimed depth advantage by other means such as increased voltage or gains, and you still haven't commented on the fact that the detector gains would have to be wound back because increased depth would also increase the ground signal? You still haven't commented on the coil TC which would be very long if we increase Q. Is this finally an admission that Minelab got the coil TC right and you and the rest of the world got it wrong? And regarding testing protocols, it's worth noting that you tested Enhance timings in ground suitable for Normal timings making the test completely meaningless. You now have the hide to ask PJ to help you test a coil?? It seems you have jumped in the deep end without your life jacket again Doug.

Parrot the depth was better than any commercial mono coil of equivalent diameter!!! The testing was done on typical GF ground (eg kingower) NOT just at the test site.Increase voltage or gains will have minimal effect on depth and sensitivity because the S/N just gets worse! eg EMI A higher Q will not necessarily result in longer Tc as this depend on what L and R are and for a spider wound coil depends on the L/D ratio and is frequency dependent (coil Q is frequency dependent) and you must take into account the inner and out winding diameters. Also where did I say i used enhance timings? You do not know what timings or detector I used parrot! As for detecting small nuggets the spider wound coil is clearly much faster which CAN ALLOW EARLIER SAMPLING than an equivalent bundle wound coil and because of a higher Q is more energy efficient(Q= inductive reactance divided by the sum of all resistances associated with ENERGY LOSSES in the coil) both of which must aid the detection of short TC targets!!! I don't know what the coil Q was but was told it was substantially more than the miserable 3.9 you quote. I am still waiting for someone to come up with a RECOMMENDED COIL TESTING PROTOCOL.ie what test's should be done, why they should be done and the best way of doing them and how the test results should be interpreted with regard to other coils. You and poor old PJ or Ufox=Paul 99 are clearly incapable of this task!!!

[Paul99]

Parrot the depth was better than any commercial mono coil of equivalent diameter!!!

Doug, you explain the science behind WHY a spider wound coil should be better than a bundle. Others have presented why it won't be better.

I am still waiting for someone to come up with a RECOMMENDED COIL TESTING PROTOCOL.ie what test's should be done, why they should be done and the best way of doing them and how the test results should be interpreted with regard to other coils. You and poor old PJ or Ufox=Paul 99 are clearly incapable of this task!!!

As the expert on how to repetitiously make unfounded performance claims for the spider coil, why don't you recommend a coil testing protocol?

[Doug2]

Doug, you explain the science behind WHY a spider wound coil should be better than a bundle. Others have presented why it won't be better. As the expert on how to repetitiously make unfounded performance claims for the spider coil, why don't you recommend a coil testing protocol?

My testing was purely in the field but apparently this is just not appropriate, or valid.So its up to you or others suggest a better coil testing protocol or for a commercial coil maker to tell us what they think is the most appropriate coil testing protocol or how they go about testing a new coil.

[mickstv]

Doug, you explain the science behind WHY a spider wound coil should be better than a bundle. Others have presented why it won't be better.



As the expert on how to repetitiously make unfounded performance claims for the spider coil, why don't you recommend a coil testing protocol?

So Paul, why did you remove that obscene picture ? Not that it matters I have a screen grab of it. But better still you've been reported and if mods needs to see it I'll gladly forward it.


Have a nice day.

[Paul99]

coil Q is frequency dependent

Would you like to detail how relevant is frequency dependence/variability of Q at the frequencies of a PI detector?

[Paul99]

So Paul, why did you remove that obscene picture ? Not that it matters I have a screen grab of it. But better still you've been reported and if mods needs to see it I'll gladly forward it.


Have a nice day.

Gee mickstv, that was meant for another forum.

Now you also have a nice day, won't you!