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TDI Coil Purchase Question

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Looking for advice on a small elliptical coil purchase for a TDI Pro. As someone pointed out in the Classified section Serious Detecting is having a clearance sale. Looking at the Coiltek 10 x 5 Joey Mono, and the Whites 7.5 x 12 TDI HI-Q Dual Field. See lots of good reviews for the Joey, but not much is posted on the HI-Q. I guess that initially the HI-Q was only available as part of a TDI-SL package and some were hoping that it would be available separately in the future. It appears that when it became available on its own that it was possibly misleadingly labeled as for MX series detectors, and I was wondering if that is why you don't find much feedback specifically on that coil.

Any feedback on either or both would be greatly appreciated.



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  • GeoBill changed the title to TDI Coil Purchase Question

1 hour ago, GeoBill said:

Serious Detecting is having a clearance sale. Looking at the Coiltek 10 x 5 Joey Mono, and the Whites 7.5 x 12 TDI HI-Q Dual Field.

Did you do a search for previous posts?  I Googled "detectorprospector.com White's TDI HiQ" and got several hits.  Here's what I think was the original (and quite long) but there are others.  Some posts talk about that 7.5"x12" dual field coil.  It sounds there as though this coil was a Miner John (aka 'Razorback') creation that White's picked up, although I don't recall White's ever confirming that.  If so there might be some reviews of the Miner John version out there.

User Karelian has lots of experience with both large box and small box TDI's and many coils.  If he doesn't respond to this thread I suggest you message him including a link to this thread.  If you have the question then others do as well.

P.S. It looks from the seriousdetecting website that the Coiltek Joey has sold out.  😞  You should doublecheck, though.

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Thanks GB. I had read all of the HI-Q threads, but really didn't find good feedback on how it performed, mostly speculation, folded, dual field, what makes it HI-Q, would it be available separately? Haven't found a good discussion of the net on performance.

If the Joey is sold out, I would still like to hear feedback from anyone who has used the HI-Q. Seems like Serious Detecting is the only dealer that has it in stock.


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Just checked and, Yep, sold out. Snooze ya lose! Hope you all now tell me it wasn't that good :laugh:. Open to other coil purchase suggestions as well.

On a side note, I have a line on a Razorback 'Piglet' coil, 5x3. Any feedback on that coil would also be appreciated.


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The Whites Hi-Q coil is an elliptical dual field, not the same design as any of the Miner Johns offerings. The Hi-Q's are similar to the Round Whites Dual Field coils only elongated. Reg Sniff helped in the design perimeters for the production of the Miner John coils as well as many upgrades on the TDI  platform. Reg worked with  Luke Lindsay from down-under to make ongoing improvements to the TDI Pro platform and Luke is a big proponent of the Miner John coils. Independently Karelian did some good testing on a rather extensive number of coils. His test results favored the Nuggetfinder Advantage 8X6 Sadie coil over a wide variety of targets. Nenad Lonic (Phase Tech) has done comparative tests with coils on the TDI and of the offerings currently available for gold nuggets his leanings are to the Nuggetfinder EVO series coils, the 12 round, 12X8, and the 14X9.  Your mileage may vary according to the targets you're seeking and the ground you are covering. Note the EVO series are flat wound and do not detect on edge to aid in pinpointing. For a first coil I'd recommend the NF Sadie.

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If you can't find a NF Sadie or Coiltek Joey (that price from Serious Detecting $106, was absolutely crazy, no wonder it's sold out!!!!) Serious Detecting is also selling the Detech 6" and 8" monoloops for around $200. That is a great price for two excellent, very sensitive and lightweight coils.

At least on the TDI SL, I was never particularly impressed with any Miner John or Razorback small or medium sized coils. The NF Sadie kicked their butts in all of my testing on smaller gold and for sensitivity in general. If you aren't prospecting those coils might be fine. 

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The 2 elliptical coils that i use the most on my TDI Pro is the Coiltek 14x9 Mono and the Jimmy 10x5 folded mono coil,the latter coil and also 2 others i bought from when Jimmy Sierra closed down his range of coil 2-3 years back,including shipping to the UK was crazy cheap including the 20mm Grande Sierra Mono coil.

The 10x5 coil is mainly used for very small gold jewellery but my favourite and on the TDI Pro almost all the time is the 14x9 Mono which is amazingly lightweight as its foam filled but of course absolutely no good in surf etc as it would want to float all the time,but as i dont do beach detecting then i dont have a problem.

The Sadie coil is the one that most folks go for but almost impossible to find one at a decent price here in the UK,but if one came along at the right price i would be very tempted and can fully understand why they sold out in the recent sale.

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Thank you all for your feedback. After my V-SAT and MXT being completely overwhelmed by the quantity of black sand and hot rocks at the site I was working in the foothills earlier this summer I've been looking for a PI detector. I recently got a line on a little used TDI Pro with the standard coil and am looking to see what to add to the arsenal. Jeff, from your comment I guess I missed a great deal, and reading some of phrunt's early posts it sounds like the Joey gave him some great results. Well damn, now to decide where to spend my limited (self) Christmas budget.

Thank you all. Wishing you a Happy Holidays!

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Maybe Serious Detecting is not the only larger metal detecting supply company that will have a sale on PI coils. Also, if you get the TDI Pro, the Razorback and Miner Johns coils may work better for small gold. The TDI SL lacks the needed raw voltage power to hit really small gold targets compared to the TDI Pro which can be run pretty hot.

Check with Gerry at Gerry's Detectors. He often has several used PI coils for sale. Good luck. 

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