field test unit no 001 "model T"

[Paul99]

I want that explanation from "master guru" Robby_H. *LOL*
^sif

He is probably still doubled over with laughter from design concept statements you made days ago. :-)

So tell me ^sif, which will give the stronger field? A bundle or basket weave, and what effect will the cross over angle of adjacent windings in the weave have? Hell, aren't you a coil design guru?

[PATCHES JUNIOR]

No problem Aziz, I am not scientist and can be easily wrong. Please explain, where I am wrong.

If I am wrong, then should be some other explanation, for my test results. It shows that basket designs, at same diameter and same wire length used, are (depending on targets and spider windings from coil edge to center surface) about 1/3 shallower in depth than bundle design, all at max sens settings.

@Dough. Yes, using more wire length, we can get more inductance, but at the same time more resistance (and more parasitic C) in coil too. Classical one level spiders are at same diameter limited in number of wire turns. We can overcome this by using multilevel (stocking) spider design but with multiple undesirable side-effect too.

No you are right WM6. The design looks neat, but does not work (On less you are making a radio antenna to listen to music) and many have tried to make it work, but figured it out like you have.

As you can see even Aziz has no idea about why it does not work and has asked others to explain it. I think they could use Aziz over on the LRL forum.

[Aziz]

PJ, this trick (to lure the explanations from me) doesn't work.
Why don't you ask your "mentor" / "master guru"?
Comeon, let us have a laugh.
^sif

[Doug2]

No you are right WM6. The design looks neat, but does not work (On less you are making a radio antenna to listen to music) and many have tried to make it work, but figured it out like you have.

As you can see even Aziz has no idea about why it does not work and has asked others to explain it. I think they could use Aziz over on the LRL forum.

You are wrong yet again! Spider wound coils DO WORK on Pi detectors including ML!!!!! It is obvious that this type of coil is a more efficient receive antenna than a bundle wound coil! The reasons should be obvious to you and even Ufox!!!!

[PATCHES JUNIOR]

You are wrong yet again! Spider wound coils DO WORK on Pi detectors including ML!!!!! It is obvious that this type of coil is a more efficient receive antenna than a bundle wound coil! The reasons should be obvious to you and even Ufox!!!!

Doug, then why is it that no competitive coil company or PI detector company is using them?

[Doug2]

Doug, then why is it that no competitive coil company or PI detector company is using them?

Don't you read? Moodz has already given an answer to this! But to help you I will repeat it!!!!! The coils are labor intensive and much more difficult to manufacture to the specifications required by say ML detectors (eg correct inductance) and are more difficult to pot than bundle wound coils.

[robby_h]

Oh man!,

I want my special answer from Robby_H "guru". Maybe he can raise his competence this time.

^sif

Give it a rest Aziz. How can you say the Moodz coil is an outperformer when you don't know the DC resistance?

Noting that we are dealing with the near field and frequencies under 100khz, why would you expect a basket weave design, where the magnetic field cuts each other winding at right angles etc, to give significantly better depth than a scramble wound coil with a circular cross section where the field runs substantially parallel to the windings?

We could wind three bundle wound coils of 15" 16" and 17" diameter and obtain different depth results on a particular nugget and we could do the same with the basket weave design so arguing about a moderate depth advantage is a bit silly if it just means substituting another size coil, and suppose by some miracle the basket weave coil gives 25% more depth, common sense dictates that the detector's gain would then have to be wound back, negating the depth increase. The only real advantage would be in S/N but only if the detector ignores EMI and cancels the ground better than current designs.

Some 3rd party ML coils have 0.6 ohms resistance and one in particular has 0.9 ohms (almost three times spec!!!) and yet no one ever notices the depth loss, most people actually favor these coils because they are lighter or because everyone else has one.

At the end of the day, this coil is just the same as other basket weave designs with slightly more emphasis on lower internal eddy currents, which is totally useless if the coil is under damped like the waveform in his "yum yum" cro pic where traditional sampling would have to be delayed until somewhere well off the page. The latest ML coils are fast enough for the fine gold timings so a faster coil will be of little benefit.

The coil also suffers the same problems as other potted basket weave coils in that edge impacts are transferred directly to the epoxy, this results in noise and hundreds of tiny fractures that can cause it to fail in days (not weeks or months) and encasing it in the usual insulating foam just makes a bulky coil bulkier.

Anyway, I think it should be rather obvious that we wouldn't start with the coil If we want to significantly improve the depth of a conventional PI detector designed for nugget hunting.

[PATCHES JUNIOR]

Don't you read? Moodz has already given an answer to this! But to help you I will repeat it!!!!! The coils are labor intensive and much more difficult to manufacture to the specifications required by say ML detectors (eg correct inductance) and are more difficult to pot than bundle wound coils.

Doug, Doug, Doug. Moodz has not even tried this coil on a detector yet! He has not even figured out if it will need a shield. And I say you sure like promoting stuff that has not seen the light of day yet. You are a mess for sure Doug.

When Moodz actually hooks this coil up to a detector and is out comparing it to other well known coils and it shows it is a better coil come back and crow about it. But till then stop acting like a fool.

[Doug2]

Doug, Doug, Doug. Moodz has not even tried this coil on a detector yet!

How do you know this?

[PATCHES JUNIOR]

How do you know this?

I knew your answer would be close to what you said.

Well lets see Mootz prove he has finished it and compared it to a popular coil used on a Minelab PI. I say he has not finished it and done a field test on it. Wanna Bet?

So as you would say "The onus is on Moodz to prove me wrong"

Please no more waffling Doug. 15 years of promoting your crap that has produced nothing is getting a bit tiring.

[Paul99]

Spider wound coils DO WORK on Pi detectors including ML!!!!!

Doug, there is a big difference between DO WORK and giving AN ADVANTAGE.

[Doug2]

I knew your answer would be close to what you said.

Well lets see Mootz prove he has finished it and compared it to a popular coil used on a Minelab PI. I say he has not finished it and done a field test on it. Wanna Bet?

So as you would say "The onus is on Moodz to prove me wrong"

Please no more waffling Doug. 15 years of promoting your crap that has produced nothing is getting a bit tiring.

"Doug, Doug, Doug. Moodz has not even tried this coil on a detector yet!'

If I don't know the answer to this then how would you know?
However do agree with me that coil losses caused by : distributed-capacitance losses,skin effect,proximity effect,eddy-current losses in neighboring objects can be reduced by using spider wound coils? ie do you believe that higher Q coils in metal detectors are desirable? If not could you be so kind as to explain why.

[Doug2]

Doug, there is a big difference between DO WORK and giving AN ADVANTAGE.

The spider would mono coil I used gave an advantage over ANY commercial coil!!!!!!!!!!!

[robby_h]

The spider would mono coil I used gave an advantage over ANY commercial coil!!!!!!!!!!!

What is the point if we have to wind the gain back!!!!!!! And I remember you saying that the QED worked just as well with low Q coils. You change your arguments like most people change their socks!!!!

For the umpteenth time, there is a difference between waving a coil over well blended ground at some test site and over typical variable gold field ground!!!

[PATCHES JUNIOR]

The spider would mono coil I used gave an advantage over ANY commercial coil!!!!!!!!!!!

I had a coil that was made from a old crystal radio antenna that was better than the spider "would" coil you used. It detected gold down to 4 meters deep. Prove me wrong.

Plus what happened to the detector this thread was named after
field test unit no 001 "model T"