Tdi Pro VS Tdi SL

[Way2go]

I had a couple of miners johns coils when I had my TDI OZ Pro. I found the coils to be good, easy to GB and had no issues with them at all.

 

[Greglz86]

Might stick with looking at the NF now that I think of it. If I decided to go with a gpx5000/4500 in the future I can stills use them and they seem to have a good reputation to them.
From what I understand the miner John coils cant be used on minelab detectors

 

[Ship of fools]

I have a Longreach 14x9 (now Minor Johns) and a Minor Johns folded 8 11x7, the 12 inch Evo leaves them pushed into a corner.
For that matter the Sadie is better.
If you want to buy them I would be happy to sell them.
Matt T

 

[grubstake]

What are your thoughts on the miner John folded mono coils? I see they sell them with the latest tdi sl with the fancy new paint.

PA member Karelian's very extensive TDI coil testing included some of these, but their results weren't very impressive:
https://www.prospectingaustralia.com/forum/viewtopic.php?id=21209

Here's the summary chart - the Nugget Finder Sadie trumped them!
https://www.prospectingaustralia.com/forum/viewtopic.php?pid=319934#p319934

 

[Greglz86]

Thanks guys and thanks to karelian for putting in the time and effort for making such a extensive comparison to such a large range of coils. :Y:

 

[PhaseTech]

Yes agree with Ship Of Fools, the Evo coils are brilliant on the TDI's, as is the Detech 11" Ultra. I'd say for hotter soils I'd go the 12" round, but if you want a bit more Sensitivity the 14x9" is the go. Haven't used the 12x8" Evo on a TDI yet but assume it would go great too, but maybe not in real bad ground?

 

[Greglz86]

Well I ripped the band aid off and purchased a Sadie. Should be here before my trip out next weekend.
The reason I chose a Sadie ove a larger coil is simply the size is more suited to the terrain I plan to detect

 

[Greglz86]

Well it works. I used the advice mentioned on this forum from time to time in regards to keeping the threshold just off audible.
Gain as high as it could go.
Kept the pulse delay at 10.
Target conductivity on low.
Frequency at whatever seemed to work. Their was only one position it didnt help at all. The best position seemed to be as far from that spot as possible. Ended up being all the way to the left.
Ground balancing was a pain in the bum. But I stayed patient and i seem to be doing it right.
The Sadie is good but Ill be looking into something that has a little more ground coverage in the future.
Running the threshold quite had me constantly wondering if it was ground balanced correctly or even turned on at times but the occasional target kept me interested. I would have been happier if I was picking up bits of bird shot and the usual small junk as Im starting to think Ive possibly missed smaller bits. Probably from not keeping ground balanced as often as I should.
All in all Im happy with the outcome

 

[ProspectorPete]

Well done Greg, pretty good results and some great lessons learned too by the sounds of it, you must be pretty happy erfect:

 

[Greglz86]

Also this is the first time Ive taken a detector out and brought something home on its first day. So Im pretty stoked about that

 

[Ridge Runner]

Congrats, keeping the threshold so you can only just hear it is the key, Coiltek make a nice 14" coil for the soley for the TDI and it seems pretty good.

 

[Heatho]

Nice piece Greg well done. :Y:

 

[Ship of fools]

Thats a nice piece! Well done.
The ground balance is fairly simple, if its quiet you have it right, if you get a low tone turn it down (just a bit), if its a high tone turn it up. Some spots get a bit tricky with both hot and cold ground very close together but a I think a good target will still be heard.
Matt T

 

[DrDuck]

Great stuff Greggles!

 

[Greglz86]

Thanks guys :Y:

Congrats, keeping the threshold so you can only just hear it is the key, Coiltek make a nice 14" coil for the soley for the TDI and it seems pretty good.

I tried a few things when our yesterday in regards to the threshold but each had a problem that I suspected was stopping me from using it at its full potential.
One thing I tried was keeping the threshold at a low hum. However I had to reduce the gain significantly to reduce the warbling. The frequency knob did bugger all to help
I tried then turning the threshold up so is was passed the warbling and seemed to be working ok but was suspecting I was missing smaller targets.
Having the threshold run just off audible seemed to be the way to go yesterday. Probably not ideal To only do that in the future.
I would like to try and get more gain when operating it with a low hum. Is this something that the mod would help fix.

 

[Greglz86]

Thats a nice piece! Well done.
The ground balance is fairly simple, if its quiet you have it right, if you get a low tone turn it down (just a bit), if its a high tone turn it up. Some spots get a bit tricky with both hot and cold ground very close together but a I think a good target will still be heard.
Matt T

Cheers mate.
Yep there were a few times I realised it wasnt set up right when I found myself digging phantom targets. The worst was the wet clay/mud that was a few inches down in some spots. Id try the ground in the bank and creek and consistently found myself digging up lumps of wet stuff that gave off a pretty strong signal. One stage I even had it in my scoop then every time I reduced the dirt by half the signal would reduce as well. Then I had two targets :argh:

 

[Ship of fools]

You do have to spend a lot of time digging!
A thing I do to help identify hot spots of dirt is Pinpoint, if it doesn't pin point accuratly it's hot dirt or multiple targets, clear an inch off the top so your coil is closer, if the signal gets stronger then your on! If not it probably hot dirt (Don't let me tell you not to dig, I may be walking away from gold!)
Matt T

 

[Ridge Runner]

Thanks guys :Y:

Congrats, keeping the threshold so you can only just hear it is the key, Coiltek make a nice 14" coil for the soley for the TDI and it seems pretty good.

I tried a few things when our yesterday in regards to the threshold but each had a problem that I suspected was stopping me from using it at its full potential.
One thing I tried was keeping the threshold at a low hum. However I had to reduce the gain significantly to reduce the warbling. The frequency knob did bugger all to help
I tried then turning the threshold up so is was passed the warbling and seemed to be working ok but was suspecting I was missing smaller targets.
Having the threshold run just off audible seemed to be the way to go yesterday. Probably not ideal To only do that in the future.
I would like to try and get more gain when operating it with a low hum. Is this something that the mod would help fix.

To get the Pro to quieten down you might have to select Low or High conductivity but "Not" ALL, the Pro gets very noisy when set to ALL. Then try and tune the frequency control then you can run the Gain up higher, I use to be able to run my Pro in ALL in the city and it was very stable indeed, The SL is a whole different beast, Nothing seems to phase the SL even in Thunder Storms in the City they still behave, But I use to be able to run my Pro flat out in ALL in the City which is pretty rare, but don't be too worried if you have to turn the Gain down because you won't loose too much depth, Ok.

One odd thing is that the Pro goes deeper when you run it with the GB turned off where conditions allow like on the Beach but the SL goes deeper with the GB turned on On the beach.

How that helps.

 

[Greglz86]

Hey guys. For those who use the 12 inch evo on the tdi. How well do you guys go in regards to sub gram nuggets? Whats your smallest bit?

 

[Ridge Runner]

I don't know mate I have never used one of their coils