Coil Choices For Maximum Depth

[Aureous]

I watched a test on a test-bed where a 2oz lump of lead was detected at its max depth with BOTH the stock 14 DOD and the 19 DOD. Same depth, same settings, same signal strength, the 19 provided absolutely zero benefit.  The owners played with it for hours on 2 detectors....then gave it back to the Gold Center in Maryborough. None of the 5 Zed owners present, bought one. Not saying that the coil wouldn't have some benefits on bigger targets or worse/better ground conditions, but that day's 'presentation' didn't sell any....

[Jonathan Porter]

26 minutes ago, Aureous said:

I watched a test on a test-bed where a 2oz lump of lead was detected at its max depth with BOTH the stock 14 DOD and the 19 DOD. Same depth, same settings, same signal strength, the 19 provided absolutely zero benefit.  The owners played with it for hours on 2 detectors....then gave it back to the Gold Center in Maryborough. None of the 5 Zed owners present, bought one. Not saying that the coil wouldn't have some benefits on bigger targets or worse/better ground conditions, but that day's 'presentation' didn't sell any....

That just proves how useless test beds really are in scheme of things. 

[Aureous]

6 minutes ago, Jonathan Porter said:

That just proves how useless test beds really are in scheme of things. 

....or that you got a 'secret sauce' 19 coil lol.  That same test bed and same target sold a lot of EVO coils to Legacy GPX users

[phrunt]

A bit like I think it would take a brave man to stand in a room with a large group of big concentric coil users and tell them the DOD coils are deeper. 🙂

 

[Prickly Prospector]

2 hours ago, Aureous said:

....or that you got a 'secret sauce' 19 coil lol.  That same test bed and same target sold a lot of EVO coils to Legacy GPX users

If I go to the trouble of putting on the 19", I don't run the same settings, and can run in normal with the larger coil, (and bogene like settings) and have picked up a couple of multi gram bits,(still not retiring I know.) missed by the Zedsearch . A lot comes down to how you run each coil. ML&JP have some great demo's on the different effects adjustments make on the zed, as well as different coil settings..Plenty of info from Reg and others who've been around, if you take the time to look.

Maybe don't ask Reg about the 19" zed coil unless you got time to spare......🙃

[phrunt]

44 minutes ago, Jonathan Porter said:

Doesn’t make what I’ve said any LESS true though. Considering this forum is kind of like a room, then I suppose I’ll have to consider myself to be brave. That’s my ‘glass is half full’ take on it, so thanks for the compliment.  Doesn’t change the facts though, physics is physics. 

with a large group of big concentric coil users 

Either way, it appears to me everyone chasing the big gold is buying big Concentrics, not DOD or DOD Spirals so much so that the big spirals and DOD coils were discontinued from international sale and only made on custom order now.  It's easy to pick up 19" ML GPZ coils cheap, few seem to want them.

People like this guy

Can you explain the physics why you believe DOD are deeper? I know little about big deep gold, all I find is relatively small and concentric is certainly deeper than DOD on smaller gold.

[Elijah]

9 часов назад, phrunt сказал:

с особыми разрешениями, большими концентрированными катушками 

В любом случае, мне кажется, что все, кто гонится за большим золотом, покупают большие концентрированные катушки, а не DOD или спирали DOD, настолько, что большие спирали и катушки DOD были сняты с международной продажи и теперь производятся только по индивидуальному заказу.

Можете ли вы объяснить физику, почему вы считаете, что Министерство обороны США глубже? Я мало знаю о большом глубоком золоте, все, что я нахожу, это небольшие и концентрированные, определенно, более глубокие, чем Министерство обороны США на более мелком золоте.

 you just need to have both

[Elijah]

It's an eternal argument

[Jonathan Porter]

On 2/27/2025 at 7:12 AM, phrunt said:

Can you explain the physics why you believe DOD are deeper? I know little about big deep gold, all I find is relatively small and concentric is certainly deeper than DOD on smaller gold.

So are the prolific posts on the subject not founded in experience or known fact? Just anecdotal evidence based on click bait forum popularism and what seems like a generally ill informed consensus? 🤔 

There are two things that determine why the Concentric’s are “Useful”, one is lighter weight than the GPZ 19 🐕 DOD, secondly and more importantly the reduction in conductive signal which is a huge advantage in a lot of conditions.

Lighter weight equals easier to swing, gravity is a law of physics, ergo only a few brave souls can actually swing a 19 DOD properly, I being one of them, so yes the GPZ19 is a DOG in that regard. However the size of the receiver is also bound by a law of physics, ergo the larger concentric X coils can’t have more ‘outright depth’ because their receive coil is ‘SMALLER’!! 😣.

I’ve spent thousands of hours on the GPZ19 coil right from early GPZ development through to current day, I have also found a lot of gold with those coils. I have also used the X coil Concentric’s for many, many, hundreds of hours so I do KNOW what I’m talking about. The X coils offer less conductive signals, less EMI, lighter weight and brighter target signals on smaller gold well within the range of detection. But they do not offer the same ‘outright’ depth of a DOD coil of the same size.

pics as proof for edification