Coils for Whites TDI Pro Oz Series

[Ridge Runner]

My 2 cents worth, keeping in mind I have an SL - I bought a MJ 7x11 folded mono and testing it in ground and in air against the sadie there was no comparison. Sadie was deeper on all targets & stronger clearer signal.

Also a key point for me was that the MJ hot spot ie the fold, is only in the very nose and about the size of a small coffee cup, so whilst you are sweeping an 11" wide strip, you are only sweeping the first 2.5" at max sensitivity. I know that we all overlap sweeps and that the hot spot is smaller at depth anyway but with the folded design you are starting behind the 8 ball.

The Razorback is the better option In Australia, The MJ is more suited to U.S. conditions, But saying that they are both pretty hot coils,

 

[ronniecruisin]

Just to clear up one point. My Pro Oz is an unmodded original later model TDI Pro Oz.

 

[grubstake]

My 2 cents worth, keeping in mind I have an SL - I bought a MJ 7x11 folded mono and testing it in ground and in air against the sadie there was no comparison. Sadie was deeper on all targets & stronger clearer signal.

Karelian's detailed testing gave similar results:

 

[karelian65]

Looking at the chart, the Razorback 10 x 6 Longreach mono coil is nipping at the heals of the Sadie all the way. It is simple to mount on the White's lower rod, is lighter and waterproof, very pointy and beautifully balanced. That depth test don't say is that it is easy to ground balance, well behaved and handles the ground well. A beautiful coil that works well on both the Pro and SL. This size coil has a smaller 'footprint' and in hot ground is easier to ground balance, quieter to run and whilst still good on larger deeper targets is very good on the smaller gold. Its performance and light weight are a great combination with the size being just right. Mounted on the Sl it makes for a super light and well balanced rig that whilst not quite a Sadie it comes very close in performance and has better handling. I got it without a coil cover, Miner John gave me one for 'free' later when I purchased other items. Gotta love that..

 

[karelian65]

The reality today is that most of the gold is small. When using a Whites Tdi Pro or Tdi Sl, there is an argument to be made for using a smaller coil. Mount a larger coil on the machine and it will find chunky gold a depth, but most of the gold is closer to a gram than an ounce.. Hence the popularity of the higher frequency VLF machines like the 24k, Fisher Goldbug and Minelab Goldmonster. I like the 24k and have my eye on it or the GMX in the near future. For those who wish to stay on board with a Tdi, go with a smaller coil. The Sadie is very good, but there are also other options to explore. My advice is something between six and eight inches, folded mono or mono. Quieter, easier to ground balance and sensitive to smaller gold whilst still hitting larger gold to reasonable depths.. The Vlf machines may be a bit noisy in hot ground and will not punch as deep as a PI machine, but for those small sub grammers they work well.

 

[PhaseTech]

The flat wound monos make the TDI come alive in my limited experience, but I guess hot ground would make things a little more difficult?
The 12" Evo and 14x9" Evo left all others for dead on my test patch. The 11" Ultra was also very good and quiet running.

Have always been curious how a TDI with 12x8" Evo or 9" Elite would go on very small gold.......

 

[XLOOX]

I picked up a 14x9 Evo from OBP on NFs Xmas deal. Cost $525 but got a free sadie which I sold for $220 so $305 for a new 14x9 Evo - cant complain about that !!

I have done some air testing which has made me quite impressed - basically for small gold the Evo looks as good as the Sadie - Yes really, and as expected for bigger stuff, the depth increases significantly.

Both with 16V battery, 10us, All, 8 gain, 8 GB, 320Ohm phones. Sadie is 1st number, 14x9 Evo 2nd number :

1grain Au ingot 70mm, 70mm
0.5g Au coin 180mm, 215mm
Oz penny 245mm,315mm
Oz 50c 370mm, 480mm ( GPX5000 gets ~500mm in hot ground)
massive iron 650mm, 850mm

I wasn't going to report back until after winter when I would have a chance to give her a good go, do some ground tests & see ground handling, as I am a little worried she might be tooooo sensitive a coil. Lets see......

 

[PhaseTech]

Have you had a chance to try an 11" Detech Ultra, or 14x9" Evo on your TDI?

 

[ronniecruisin]

Hi. Nenad. No. I haven't . I'd like to. Money's a bit tight for more toys though. I suspect they'd work quite well.

 

[Found-It]

Thank you for posting the detailed testing chart. I'm still learning a lot about detecting so appreciate it!

 

[kadir6141]

Hi. Td dual field coil cable connector how tx to rx pin. Can you help me.

 

[XLOOX]

ALL coils from mine lab, coiltek,nugget finder and others that are for Minelab GP and GPX series detectors will fit and work on the Whites TDI series, including SL and SPP. That includes mono and DD coils.

BUT coils over about 14in will need the delay adjusted as they will not work at delay below 12us. that means they wont find tiny nuggets but will find anything bigger than about 0.4g.

 

[XLOOX]

kadir,.i have that info but am in WA until Feb and info is in qld .
if noone replies by Feb I will get back to you then.

 

[XLOOX]

I vaguely remember reading something by TDI guru Reg Sniff on another forum ( cant remember which one) that the SPP PCB is same as SL but uses fixed resistor rather than a potentiometer to control delay.

I have a post here in PA in Whites section with a photo that shows size of delay pot and where it is connected on the PCB.

If you want to use larger coils on SPP then converting it to an SL is prob the go.