My Thursday X-coil Iffy

[Jonathan Porter]

55 minutes ago, Steve Herschbach said:

Could also be you are being a tad sensitive and defensive JW.

Definitely wasn’t trying to have a go at JW nor offend him, my point was that even a magic wand sometimes finds itself lacking. We’ve seen the potential in the right environments but not all areas are conducive to that potential.

JP

[DigsAlot]

Don't we have enough marshmallow people in the world. We are miners, our hobby is what others call work. Suck it up butter cup. Straight talk leads to positive long term development. No one was attacking. Mitch not finding gold in played out areas sheds positive light on the complete picture of the x-coil. IT'S JUST ANOTHER COIL!!!

 

[Jonathan Porter]

Here are the results of the last time I used an unmentionable 😀 The key is to locate the right areas where an advantage is to be had. I was quite impressed with the sensitivity of the 17” elliptical and did really well with it. The key advantages here was firstly coverage, secondly sensitivity for such a large coil and lastly weight.

Would I have found these with the GPZ14?🤔 Yep, sure would have. 

JP

 

[DigsAlot]

JP, I am pretty sure that was my Nug I dropped last week. If you be so kind as to mail it back to me here in the US.

[Jonathan Porter]

1 minute ago, DigsAlot said:

JP, I am pretty sure that was my Nug I dropped last week. If you be so kind as to mail it back to me here in the US.

Sure thing, before I do what was the exact weight again?🤔🤪

[DigsAlot]

5 oz and dont be shaving any off I will know.

 

Nice color to those Australia nugs. I wish we had that open space to detect.

[jasong]

Coverage, sensitivity, and poking that nose into places. The 17x12 is actually skinnier up front at the nose than the 10" is, so I keep it on even in rocky washes, while retaining the depth advantage too. It's the coil I use 95% of the time now.

I've said it before, but I can't say it enough, it's the perfect size coil IMO. If a guy happened to be testing a new detector at some undetermined time in the future, it would be a great recommendation to the company for a new stock coil size.  (A longer shaft is definitely needed though)

 

[Jonathan Porter]

4 hours ago, kiwijw said:

You will never know that for sure unless you waved the ML 14" over it before disturbing the ground. How deep was it?

JW 🤠

Let just put things into perspective here JW🤠, I test and use metal detectors for a living.😬 Which part of my in the affirmative public statement ”Would I have found these with the GPZ14? Yep, sure would have“ is giving you trouble?🤔

The main advantage of the 17” Elliptical coil in that particular detecting scenario was in the ground coverage aspect of its contribution, It’s got plenty of sensitivity sure but so does the GPZ14”. In a lot of the ground I work it is a real chore to use the unmentionables it truly is, otherwise I would have them on my machine permanently. If I was working WA all the time, like Davsgold does, I would be using the 17” elliptical a lot, its a good size and weight for all day prospecting covering a lot of ground with each swing and will snap onto the little surface dwellers quiet effectively so long as the ground is not too variable with high X. My early input/recommendation is the reason why the 17” elliptical was made in the first place.

The unmentionables are a pretty OK coil now with limitations, I’ve put pictures up off the gold I‘ve found with them, substantial amounts of gold in reality so I ponder the reasons for the inquisition other than veiled attempts to discredit me. The subject about the coils is interesting and has created some pretty informative dialogue but the constant chest puffery every time someone says anything other than a glowing report has worn very thin.

I know Steve is heartily sick of all the cranky posting and having to delete irrelevant posts that stray away from good manners, I find it annoying that good material that can benefit others in their quest for gold keeps getting culled because of the bun fights. The reality is the coils are NOT brilliant everywhere, but in the right locations with a little thought they do provide some advantages for the brave.😇

JP

Some more gold pics, found with the mighty 17” round, this one WAS missed by the GPZ14 coil!😎

 

[Jonathan Porter]

12 hours ago, davsgold said:

Nice going JP, looks like good depth and a nice reward, that is the type of gold the x-coils like, the rough slightly porous type of gold that often gets missed quite easily.  I do like the 17x12 spiral x-coil for WA, my favorite coil for sure.

Is it possible for you to say in you opinion why that type of gold is seen more "easily" by some coils.  Time constants, or the porous type not returning the signal etc etc 

cheers dave

Hi Dave, I have to disagree with you about the unmentionables liking a certain type of gold. The GPZ 7000 likes gold regardless of which coil is put on it. If you tried to force the GPZ to demodulate earlier than the electronics would allow the detector would simply not work at all.

In my opinion there are a couple of things going on with these coils which is providing the stronger target signal, one is the spacing of the Rx relative to the ground. Obviously if you bring the coil closer to the ground it is going to produce a louder signal especially on the smaller gold. You will notice the UMX coils are a lot thinner than the OEM GPZ coils, this partly explains why the UMX’s saturate so readily, Minelab could have done this with their coils too, so this then should logically bring about the sensible question of why don’t they? Especially in the case of the GPZ19 because if the Rx shell was thinner the coil would be a heck of a lot lighter which we would all greatly appreciate😬. TBH I feel Minelab over-engineer their coils, the fact that the UMX coils are getting away with so much strongly suggests ML could be a lot more liberal with their design.

Secondly, the wide Tx winding of the UMX Spiral wound coils does provide a sensitivity increase, I’m pretty certain it’s not because the winding is forcing an earlier demodulation like a flat wound mono does but it definitely does increase sensitivity. To my mind it is akin to a smaller coil having more windings to get the impedance right, the more windings a coil has the greater the sensitivity.The combination of closer to ground Rx and the spiral wind do increase target signal loudness and response but as I have said it also increases X signal and Saturation signals as well as salt signals (you should discover this in WA this year because they have had a very wet summer in places😬).

So the major bug bears IMHO in the UMX sphere is poor X balance on the ferrite (although that has improved a lot over time), touch sensitivity in General Difficult (to the point of unusable for me personally in anything but football pitch smooth terrain), Saturation signals in highly magnetic soils (manageable by good coil control) and elevated salt signal when salt is present.

So in the right conditions as shown in my previous pictures there is an advantage with these coils and yes they can be used in difficult terrain but the advantage tapers off in proportion to the ground type negating the advantage or even potentially hampering performance compared to OEM.

JP

Some more pics, numbers of pieces out of the same hole. The ground looks noisy but in actual fact I was able to use High Yield normal here, perfect conditions for these coils.

 

[Jonathan Porter]

I’ve gone back and added some eX’s for you JW.😇 I used the abbreviation UM because most forum readers are heartily sick of the X coil subject, it’s done tongue in cheek to try and brighten up the mood. 🤠 Lighten up JW, if I thought the UMX😜 coils were pathetic I wouldn’t be putting up pictures of the successes I’ve had with them.

I’m looking forward to Mitchel’s latest report on how he’s been doing in his search.😀

JP🤠