General information and depth for the TDI SL 12 PI?

[RockRaven]

Reading up on various PI machines, wondering about the difference between the less expensive and often waterproof PI machines and the TDI SL? Obviously a bit lighter than many of the dive-ready machines, wondering about the various modes and features on the TDI SL as compared to the simpler machines especially the Surf PI Dual Field and the Tesoro Sand Shark. Also interested in the Large Item mode on the TDI SL and what sort of real world experiences with depth, also very interested to know if the machine has any greater ability at metal or conductivity ID compared with simpler PI machines. Thanks in advance

 

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[Gold Itch]

Reading up on various PI machines, wondering about the difference between the less expensive and often waterproof PI machines and the TDI SL? Obviously a bit lighter than many of the dive-ready machines, wondering about the various modes and features on the TDI SL as compared to the simpler machines especially the Surf PI Dual Field and the Tesoro Sand Shark. Also interested in the Large Item mode on the TDI SL and what sort of real world experiences with depth, also very interested to know if the machine has any greater ability at metal or conductivity ID compared with simpler PI machines. Thanks in advance

Are you Sure that You really Want to Dig That Deep On A Big Item, lol. I found the Steel Supports to a Subway Tunnel with It that was Many Feet Down, Does that Count??, Or A 6"Aluminum Foil Pie Tray At 4 Feet, Or with the Gain Set to ZERO it picks up the same Item At 2 FEET and Blowing Your Ears Off At 20 Inches,

Unless you Own A Mini Digger/Back Hoe, You won't be able to Dig In One Day How Deep the SL Can Go With The Standard 12" DF Coil On Large Items. There is One thing that NO ONE Ever Thinks Of about When Discussing the TDI Range of Machines Is, Unlike the Others Whether they Are PI's or VLF's and That Is that The TDI's Can and Do ID the Target as To Whether It Is A Low Conductivity or High Conductivity Item AT FULL Depth and Although It Is A Crude form of Discrimination It Works and works well.

hope this helps

 

[Johnnoh]

The TDI SL has a sophisticated ground balance circuit that allows you to switch between high/low conductive targets - or both. I think that is the main difference between the a TDI and lower end units. I do not find much difference in depth with coin size objects with the ground balance on as compared to a decent VLF machine - in good ground.

 

[Gold Itch]

The TDI SL has a sophisticated ground balance circuit that allows you to switch between high/low conductive targets - or both. I think that is the main difference between the a TDI and lower end units. I do not find much difference in depth with coin size objects with the ground balance on as compared to a decent VLF machine - in good ground.

Maybe the coins weren't any deeper, They seem to find tiny stuff very Deep way beyond what a VLF Can, As One of our members just posted, I would Like to spend 3 months solid 24/7 just testing and writing down the results, These Machines are A Bit of A Dark Horse.

But they seem to be Hot on Low Conductive Items,

 

[RockRaven]

Four feet on a 6" pie tray is exactly the type of information that I am looking for in regards to both sensitivity and depth. Although I am primarily interested in the TDI as a nugget shooting machine, the many adjustments and features plus quite a bit of raw power attract me verses only seeming to have one negative that I have heard of which is rapid usage of the batteries. Although I can certainly be considered a newbie in regards to metal detecting, I am not new at digging holes at all. I do have some dirt-working equipment although not a mini-excavator, and I also blacksmith my own digging tools. Dug lots of holes and trenches as general contractor, best friends with a shovel while I was a hoddy

I work some areas with very little trash, almost zero on my VLF other than very than a few shell casings and occasional bullet, but very deep pocket gold both in streambeds and on hillsides. In the streambeds, finding iron means finding gold, last activity by prospectors was long ago, and the washed down iron will be in the same spots as gold nuggets or potential panning material, but often deep down due to an old time use of the bedrock up above as a sluice. Huge amounts of extremely good material were washed down into the lower streambeds by a hydro- tunnel they built long ago, with very little actual extraction of gold or nuggets from the material washed down. On the hillsides there is pretty much no trash at all, paleo-placer pockets that can be buried etc, but, when found, are exceptionally valuable.

My final interest in "deep" is for cleaning up relic hunting sites once I go over them with a VLF to find large objects and for areas with possible caches but low trash, and the TDI looks like the right tool for the job yet again, two box type of detectors will not be much use for most of what I am looking for. Thanks for the information everyone

 

[Johnnoh]

I ran my TDI SL with the RNB 2900 pack in 30* temps for 4 hours straight and was still showing 11 volts when I got home. You definitely want to upgrade the battery as the TDI will perform better with higher voltage.

 

[Gold Itch]

I ran my TDI SL with the RNB 2900 pack in 30* temps for 4 hours straight and was still showing 11 volts when I got home. You definitely want to upgrade the battery as the TDI will perform better with higher voltage.

I have done Tests with Batteries here's what I Got,

1) The Standard HD 2200mah NiMh Pack 4 hours 20 minutes
2) The Dry Cell Pack Fitted with 8 X 2650 mah NiMh AAs =(11.63 volts) 6 hours 37 minutes
3) Modified Dry Cell Pack to Fit 9 x 2700 mah NiMh AAs =(13.009 volts) 6 hours 38 minutes

NOW IF YOU USE:- Righto If you use 2900 mah NiMh Batteries you should get Around 7 and A half to 8 Hours Run time, which is more than enough with out Taking A Break, So My Advise to All You Fellow TDI SL Brothers and Sisters, Is To Use the Dry Cell Pack with either 2650s, 2700s or 2900s As Your Main Pack and use your Standard HD 2200 Factory Pack As Your Backup,
Using the 2650s and the 2700s works out 4 X Cheaper than Buying the RNB Pack.

NOW YOU:- Now You might of noticed that I Modified the Dry Cell Pack To Except 9 X AA's, Why you might Ask??, Well many People have Claimed that By Increasing the Input Voltage That you would Get More Depth?? Well It Did To A Degree But it helps the Sensitivity more than depth because it is running at A Peak Voltage, Is it worth the $10.00s to buy an extra Battery and the Single Battery Holder, Maybe?? But for ease of Use I am Going back to using 8 X 2700+ Batteries, Although I was Running A Higher Voltage It did Not Give me more Run Time as I expected, Because when you increase the Input Voltage that has A Down Side, Because The TDIs will Consume more Amperage as with all things Do although that 13.00 volts does give you a Happy feeling Inside,

If you are going to Carry Disposable Batteries then Only Use Energizer Lithium's as they have A Much higher Voltage than Duracell's and Normal Energizers at 1.61 Volts, Where AS The Energizer Lithium's Have 1.83 volts which @ 8 X 1.83 = 14.64 Volts, DON'T PANIC Because the TDI SL Can Run 16.00 Volts Safely, OK,
NOW These Energizer Lithium's Have A 10 Year Shelf Life, and have Working Temperature of -40*c to + 40*c++, and they are the only Battery that Is Guaranteed Not To Leak, So If you Own ANYTHING of Value to YOU Only Use these Batteries In It and Even more So with your Detectors because The High Voltage Makes the Machine A Bit Deeper and A Little More Sensitive and A Longer Run Time than Normal Energizers or Duracell,

Please Note That Duracell's work Better than the Normal Energizers because Duracell's power slowly goes down, Where as Normal Energizers stay Bright and then the Voltage suddenly drops Fast and if you are using them in a flash light/Torch Then Don't Be Surprized if you find your self in the Dark,

Anyways I hope this Helps,

 

[Gold Itch]

Four feet on a 6" pie tray is exactly the type of information that I am looking for in regards to both sensitivity and depth. Although I am primarily interested in the TDI as a nugget shooting machine, the many adjustments and features plus quite a bit of raw power attract me verses only seeming to have one negative that I have heard of which is rapid usage of the batteries. Although I can certainly be considered a newbie in regards to metal detecting, I am not new at digging holes at all. I do have some dirt-working equipment although not a mini-excavator, and I also blacksmith my own digging tools. Dug lots of holes and trenches as general contractor, best friends with a shovel while I was a hoddy

I work some areas with very little trash, almost zero on my VLF other than very than a few shell casings and occasional bullet, but very deep pocket gold both in streambeds and on hillsides. In the streambeds, finding iron means finding gold, last activity by prospectors was long ago, and the washed down iron will be in the same spots as gold nuggets or potential panning material, but often deep down due to an old time use of the bedrock up above as a sluice. Huge amounts of extremely good material were washed down into the lower streambeds by a hydro- tunnel they built long ago, with very little actual extraction of gold or nuggets from the material washed down. On the hillsides there is pretty much no trash at all, paleo-placer pockets that can be buried etc, but, when found, are exceptionally valuable.

My final interest in "deep" is for cleaning up relic hunting sites once I go over them with a VLF to find large objects and for areas with possible caches but low trash, and the TDI looks like the right tool for the job yet again, two box type of detectors will not be much use for most of what I am looking for. Thanks for the information everyone

Sorry I did not Answer All your Questions as For Nugget Hunting The Standard 12" DF Coil will Pick up Items the Size of 0.10 Grams or 0.004 ozt or 0.06 dwt or 1.6 Grains,
But If you really want the upper hand on Small Gold then Get the Miner John 9x5 folded mono Coil because There are tests by Luke on YT showing him using the TDI SPP and the Pro picking up A 0.03 gram Nugget, NOW That is Tiny, and more like GMT and GB II Territory But with A PI Machine,
Also the Miner John Razorback 12x7 ?? Longreach Coil Is A Good one to get as an All Rounder, The Razorback coils are white so they reflect the heat and don't suffer from heat making the coil start Falsing,, But that Little Black Folded Mono Is the Weapon of Choice when searching for Fine Gold, Ok.

Good Luck.

 

[Hard Prospector]

Your experimentation of battery supply options for the TDI is impressive John, thanks for passing on this knowledge. The TDI 9x5 folded over mono (Miner John), Whites TDI 7.5 Oz Mono and the 4x6 TDI shooter have been the best small gold producer coils for me by far.

 

[Gold Itch]

Your experimentation of battery supply options for the TDI is impressive John, thanks for passing on this knowledge. The TDI 9x5 folded over mono (Miner John), Whites TDI 7.5 Oz Mono and the 4x6 TDI shooter have been the best small gold producer coils for me by far.

I have the 7.5 DF Coil which is supposed to be good on Tiny nuggets, Not the 7.5 OZ Mono and I am not Sure what to make of it as of yet, I have never seen the 4x6 TDI Shooter Coil, so I have to rely on After market Coils at the moment,

I am still working on the battery system and I need some true 2900s to get the full 8 hours from them,

John