Waterproof White's TDI

[steve herschbach]

I have every detector angle I want pretty well covered but there is one gaping hole in my tool box - a submersible PI detector. Since I am into prospecting I want one that can ground balance, and right now that leaves only one option - the Garrett Infinium. Now I have used the Infinium a lot, and it is a good unit, but I have really done battle with it in saltwater environments and in areas with electrical interference. Not issues really for prospecting but if I have a waterproof PI I would like to also use it in saltwater or anywhere else for that matter.

The White's TDI addresses the issues but until now there has not been a waterproof version, despite that being a much requested thing ever since the TDI came out. There were various technical issues to overcome but it has been something on the backburner for some time. Carl at White's has stated on another forum that "It's no secret that White's is working on a waterproof TDI. Actually, it's my personal project. All-new case, all-new circuit. Goal is 6us, so it might not run Coiltek coils">

So short of Minelab cramming a GPX 5000 into a CTX 3030 housing (I am not holding my breath) a submersible TDI is number one on my wish list for 2013. I have a summer of gold dredging planned and am hoping I will have a waterproof TDI along to use scanning the sides and bottom of our work area as we go. I have a myriad other uses besides but mask and snokel work in creeks is high on my list of uses for a waterproof TDI. If a shorter pulse delay can be achieved in a production unit it should be pretty hot for a PI on small gold. I hope we have a chance to find out before summer.

Steve Herschbach

 

[Arizona Slim]

Won't 6us be too hot for saltwater use? It would be great in freshwater!

 

[Hoser John]

Tesoro has made 2 great units that are time proven over many years-one pulse and one vlf for underwater useage....John

 

[steve herschbach]

Sand Shark will not work for me - no ground balance. Great little detector though and would do the trick for most people. Ground balance is critical for me though.

The TDI unlike the Infinium offers the option to run without ground balance to get max depth in low mineral ground, but activate the ground balance when the going gets tough. Hopefully this ability to switch modes will be retained in a waterproof version.

I am not trying to convince anyone they need a waterproof TDI. I am saying I want a waterproof TDI. Hopefully it will have GB on or off, adjustable pulse delay, and interchangeable coils. If one does not come available by spring I will get another Infinium instead.

Steve Herschbach

 

[steve herschbach]

If the unit is locked at 6us it would be too hot for salt water for sure. Which is why I believe it will offer an adjustable pulse delay. It would make no sense to limit the market to fresh water only.

Steve Herschbach

 

[seeker41]

would also be usable at 8, 8.5, or 9us. i am a beach goldhunter and anxiously await a machine that will work in the salt enviroment at or near 8us!!!!!! if you have ever seen a eric foster aquastar II(8-8.5us) in action on the beach you would be ammazed!!!!!
there are things in the works from a few manufacturers and possibly one individual and a realization of the un-tapped market. the big question is probably who will get one to market first rather than if they will!!
keep the faith steve, im with you on this one!!!!!!!!!
chuck.

 

[tvanwho]

I thought you might have a custom waterproof TDi to show us Steve, after your MXT conversion?
If they do come out with a unit like this, how expensive do you figger it will be?

-Tom V.

 

[steve herschbach]

Hi Tom,

No, I really prefer factory built. I have no idea what a waterproof TDI would retail for either. I am the odd guy out always hoping for high power premium price detectors so from my perspective less expensive is not always a good thing.

Steve Herschbach

 

[parrott]

Steve.... 6us?.... May not work... chex with Reg. I have an early hole #13 off the line... Did good with it
under high lines at Stringer... epithermal... (ref photo pg 100 ...."Three Hours to Gold from Southern California).
Being first is everything.

 

[starvin]

A waterproof TDI. It was something of an idea I would like. Called White's and asked Mary. She said it would be awhile. No denial, but not confirming either. Interesting...

 

[steve herschbach]

n/t

 

[Reg]

Jim,

By changing coil design, 6 usec is possible. I have a coil working fine at 8 usec on the bench now and it could run at 6 usec if I changed the timing circuitry.

One other big advantage of this idea is a reduction of noise. I am in the process of trying something different that may further reduce noise. If my idea works, it will have the potential to be used on all TDI's as a way of reducing noise if the special coil is used.

One note though and that is, the maximum noise reduction would also require the changing of the preamp.

Reg

 

[steve herschbach]

As you know I have always been "TDI friendly". I have been waiting for a waterproof TDI ever since I ran the prototype in Hawaii. I hope I do not have to wait much longer but I am a patient fellow. I am hoping that a waterproof version will also work well enough above water that it can be my one and only TDI. I am trying to get my number of machines down to a reasonable level.

Steve Herschbach

 

[tvanwho]

I was gonna take my new used Platypus waterproof coil for a spin with my TDI until I noticed the ears on the coil have issues with the Tdi stem. I had to drill the ears out so the Tdi bolt would fit thru them.
Unfortunately, the stock nylon Tdi black bolt is also too short for the Platypus ears and it needs 2 FAT washers in between the ears and the Tdi stem. My local hardware store has nylon
bolts but nothing even close to the Tdi bolt and I need one an inch longer than the stock bolt? Any suggestions? I am assuming metal bolts are a no- no?
Thanks.

-Tom V.

 

[steve herschbach]

I suggest you use a Minelab lower rod with the coil. The rod will slide just fine into the White's upper rod and can be snugged up with the twist lock. I would not drill or modify the coil.

Steve Herschbach

 

[tvanwho]

Can I buy the Minelab lower rod and bolt from AMDS or where? Can you get me a price with shipping to zip 60502?Maybe send me a pm.

Thanks,

-Tom

 

[Reg]

TomV,

I build most of my own coils now and the hole on the housings is small compared to the White's coil bolt. I use 1/4" nylon bolt and nylon wing nuts and have yet to have one fail, but I do carry some with me all the time just in case. You can buy the nylon bolts at various lengths so it is an easy thing for me to change coils and even try a ML coil if I so desire. Since I do have a couple of ML coils and test them once in a while, a simple cheap approach works for me.

Steve's suggestion works well if you have easy access to a ML lower shaft. Unfortunately, where I live there is no shop carrying ML equipment and I normally do not use a ML coil, so the easiest thing for me to do is what you indicate, use a White's lower rod and a smaller longer bolt. BTW, I made some heavy washers for spacers out of some thick rubber matting. It worked well for my purposes.

Reg

 

[steve herschbach]

I admit that I assumed Tom had a Minelab lower rod laying around since he had a Minelab compatible coil. Much cheaper just to do as you suggest than buy a lower rod. Like everything else Minelab they are not cheap.

Steve Herschbach

 

[tvanwho]

McMaster Carr online catalog,page 3152 ,has plastic bolts in larger sizes than my hardware store has,altho they come in packages of 10-25,not just one? Which one should i buy? Is it 3/8 x 16 threads or what? They' re not showing plastic nuts so I may need to reuse the Whites plastic nuts. These bolts do have hex heads tho. Since I have already drilled out the Platypus coil ears,getting a Minelab lower rod probably won't fix my issues?

-Tom

 

[Reg]

Tom,

You might check ebay. I think you should be able to find small quantities of what you want.

Reg