Jump to content
Nugget Shooter Forums

Recommended Posts

The TDI SL scores again! This time, it's a really nice one.

Here's the story. Working a hydraulic pit in the Sierras, I was working slowly up along a stacked pile of tailings. It was a narrow, flat "trail" where in the old days, they had placed either the sluice or the hydraulic pipes. It was a flat area of decomposed bedrock, filled in with rubble to make it smooth. Right at the edge of the rock pile, I got a very weak "woo" signal. It took a bit to break up and get down into the decomposing bedrock. The signal remained weak, since the hole was small and I could barely get the point of the loop into the hole. Once the target was out, it was a booming signal.

Now, the reason why such a big nugget gave such a weak response is simple; it was on edge, wedged into the bedrock sideways. It was only about 6 inches deep and I couldn't get enough room to sweep from all sides. But, I heard it and dug it as you must do with all weak signals. Especially in an area like this. The conditions were ideal; bedrock, old tailings, mild ground. I was using the 10x6 Jimmy loop with the settings at the standard for nugget hunting. Wt of the nugget; 5.6 dwt.

Pictured also is the two largest nuggets I've gotten this month with this machine.

Digger Bob

post-413-0-85985600-1317154146_thumb.jpg

post-413-0-90577200-1317154157_thumb.jpg

post-413-0-42811900-1317154172_thumb.jpg

Link to post
Share on other sites
  • 2 months later...

Strange there is not more--almost any--posts really about them on many forums?? TDI been out quite awhile and silence mostly. Great lookn' gold though and thanx much-John

Link to post
Share on other sites

Strange there is not more--almost any--posts really about them on many forums?? TDI been out quite awhile and silence mostly. Great lookn' gold though and thanx much-John

Hate to be bruatally honest... but I think the reason there's not many posts about the SL is because it's very inferior to the TDI and TDI pro. I hunt along side two guys with SL's and I have the Pro. We did some tests. On a course (pitted) 3 dwt hugget I can detect it at 10", the SL's at about 4-5". On a little 1/4 grammer, I can get 3-4", the SL has to be right on top of it to pick it up. Both have the stock 12" duel field coil.

Those are the tests we did and consistantly the SL came up short. Funny thing is, after that the guy with the SL went out and bought a 5000.

I bought the SL and then traded up for the pro. I'm sorry to say, but the SL is a dumbed down version of the TDI... and the the TDI compared to a minelab... well... the guy that found that 3 dwt nugget found it at 15-16" with a 4500 in highly miniralized ground. No TDI is going to hear that at all.

Link to post
Share on other sites

Up here in the golden crescent-highly mineralized area-the new GB Pro are kickn' butt all over the place. Old patches that have been pounded by minelabs,whites,tesoro and all producing GREAT finds again. TAU has sent me dozens of pix and WOW is all I can say. But silence on TDI is indeed baffling??? Merry Christmas to one and all-John

Link to post
Share on other sites

The tdi sl does much better with small gold if u use the 7.5 inch whites coil. also much smoother threshold, and much more comfortable to swing than the pro due to its light weight.

Link to post
Share on other sites

Hate to be bruatally honest... but I think the reason there's not many posts about the SL is because it's very inferior to the TDI and TDI pro. I hunt along side two guys with SL's and I have the Pro. We did some tests. On a course (pitted) 3 dwt hugget I can detect it at 10", the SL's at about 4-5". On a little 1/4 grammer, I can get 3-4", the SL has to be right on top of it to pick it up. Both have the stock 12" duel field coil.

Those are the tests we did and consistantly the SL came up short. Funny thing is, after that the guy with the SL went out and bought a 5000.

I bought the SL and then traded up for the pro. I'm sorry to say, but the SL is a dumbed down version of the TDI... and the the TDI compared to a minelab... well... the guy that found that 3 dwt nugget found it at 15-16" with a 4500 in highly miniralized ground. No TDI is going to hear that at all.

The holidays have kept me from commenting on some of this silliness, so here goes...

First of all, it's true the standard TDI and PRO do get a bit more depth than the SL. HOWEVER, it is not as great a difference as some would believe. In the hands of an experienced operator, the difference is only about 10 to 15 %. This is on virgin targets, not planted.

Secondly, any one who has detected long and been successful at it, will tell you that raw depth is only one aspect of ANY detectors overall performance. If all you want is depth, then pay $5000 for a Minelab, knowing it is heavy, with dangling cords that get hung up on brush, and with a less than steller repair record. Or pay less than half that and get a machine that will find 90% of what a Minelab will.

Thirdly, the addition of the quieting circuitry on the SL means you can hunt at Max gain, even in All Conductivity, even under power lines and near other detectors. The smooth, steady threshold means you can hear those whispers of signals that are masked by the warbling threshold of the standard TDI. To get that smoothness on a TDI, one must reduce the gain to half. Even at that it gets impressive depth, but try to run it at max and those whispers are masked by the instability.

There is no perfect detector that does everything. Those of us who hunt a lot and have been for a long time usually have 2 or three machines, in addition to a stable of loops. I have 3; a Goldmaster for those little bread and butter nuggets near the surface. A Minelab 3500 for those big deep ones. And a TDI SL for all the rest. It has become my grab and go machine for most conditions. It will handle any ground I have tried and at max gain. I've yet to find any it can't balance out with ease, even that nasty stuff down by Mariposa that Grubstake took me to.

Many opinion polls on several forums over the years have asked the same question. "What's the adverage depth that you find nuggets?" The response among experts is the same - 6 inches. That's 50%. That means 25% is shallower and 25% are deeper. So right off the bat, the TDI SLwill detect 75% of the detectable gold that is out there. And it certainly will go deeper than 6 inches, so that brings the total up to, let's say, 85% What makes up the other 15%? Too small or too deep, and there's where the other machines come in. I have already demonstrated the SL will detect a 1 grain nugget, and that's with the stock 12" loop.

Put a small loop on and it stands out even more. That's darn small for a pulse machine. And the SL will detect smaller gold than the TDI or PRO.

A dumbed down version? Hardly! Is an 8" loop a dumbed down version of an 11" loop? Is a 4500 a dumbed down version of a 5000? Is the TDI a dumber vesion of the Pro? No to all. What you have are differences, not inferiority. Different products for different applications, price ranges and markets. The entire TDI line is designed around those differences. Put me and my SL in the same field with someone using a TDI and depending on the condtions, we'll come out even. He may get a little more depth, but I'll dig less trash, and be less tired at the end of the day. It's smaller, lighter, smoother, easier to adjust, and simply more comfortable to use. We knew we were sacrificing a bit of depth by adding the quieting circuitry. But I felt that it was worth it given what we gained in stability.

If one takes the time to learn the machine, use the proper balancing and hunting techniques, practice and patience will pay off. Amatuers get impatient and easily frustrated by a lack of instant success. They see what the experts are finding and think they can grab a detector and go right out and get rich. A machine is only as good as it's operator who takes the time to learn it's capabilites as well as it's drawbacks. Then there are those who claim to be experts because they have an agenda of their own, like selling aftermarket accessories. Ask them some pointed questions and you may soon learn they really don't know that much, just think they do.

Finally, remember this old Axim: "It's a poor mechanic who blames his tools."

Digger Bob

Link to post
Share on other sites

Thanks for the post Bob! I have a couple of Whites detectors myself(original TDI and a GMT) and enjoy reading about others finding stuff. I bought the TDI honestly because of price and Whites stand up warranty. For the few times a year I really get to use it, I could not justify the cost of a minelab. I would love to have one.... but the reality is, it's not gonna happen anytime soon.

Hope to hear more from you on here.... with more Whites nuggets!

Link to post
Share on other sites

The holidays have kept me from commenting on some of this silliness, so here goes...

First of all, it's true the standard TDI and PRO do get a bit more depth than the SL. HOWEVER, it is not as great a difference as some would believe. In the hands of an experienced operator, the difference is only about 10 to 15 %. This is on virgin targets, not planted.

Look, I was giving my opinion of some simple test we did after seeing the SL was losing quite a bit of depth compared to the pro. Yes they were planted tests packed back over with dirt, and then we did some on top of the ground tests. It was still apples and apples. And 10 to 15%? Hardly. On a small picker if the pro can get 3" and the sl has to almost scrape the coil on the nugget, that's not 15%. I also noticed that the drop off rate of a response if very sharp on the sl compared to the pro. The pro would gradually fade away the target but with the sl it would be there and then gone.

Secondly, any one who has detected long and been successful at it, will tell you that raw depth is only one aspect of ANY detectors overall performance. If all you want is depth, then pay $5000 for a Minelab, knowing it is heavy, with dangling cords that get hung up on brush, and with a less than steller repair record. Or pay less than half that and get a machine that will find 90% of what a Minelab will.

I think depth is an imortant factor these days. I don't know about you but all the places I go to have been hammered, by minelabs no less. So depth is important. I don't want to argue with you but if you're saying the SL will find 90% of what a minelab will, then... Wow

Finally, remember this old Axim: "It's a poor mechanic who blames his tools.

It's also a poor machanic that uses the wrong tools for the job. I can bang all day on a brake drum with a screwdriver to break it free. Will I get the drum off? Sure. But could have accomplished that task so much easier with a hammer.

I'm only posting my opinion of what I saw first hand, just for other peoples information. They can believe it, or not, look into it further, whatever. It's not like I sell detectors or coils so I really have no alterior motive for saying one thing or another about any detector. Just giving my opinion. I appoligize if that bothered you for whatever reason...

Link to post
Share on other sites

I really hadn't planned on responding but it is time. First of all, I have a question for wjbell and that is, is that your TDI Pro for sale over on the Nuggethunting forum?

Next, Digger Bob is correct on the possible depth difference between the SL and its big brothers. How do I know? Well, I have enough technical documentation to determine this from an engineering standpoint and I have verified how the SL works and compares to other TDI versions by testing of the SL prototype sent to me for evaluation.

The primary reason for any depth difference is the fact the SL does use a slightly lower voltage battery. Under the worst case conditions, the battery difference can be quite a difference in voltage applied to the pulse. This could result in a small depth loss. Outside of that, the fundamental design of the SL and the other TDI units are similar enough that little or no depth to all sizes of gold should be lost.

With that said, any other difference of any significance would be a matter of adjustment of one or more controls, swing speed, or the possibility of a defective unit. One adjustment seldom checked is the frequency adjustment designed to reduce noise. On the SL, there is a special circuit built in that is there to fundamentally minimize noise in the threshold. This circuit works great but in doing so, can have an impact on depth if the frequency control isn't properly adjusted. Under normal condtions, this depth loss is not significant but could be noticeable.

I do agree that the smaller coil is probably the best for the SL also. However, I use a smaller coil even on my TDI which has several mods to enhance it to the Pro version in many aspects.

As I have said multiple times, the TDI is not for everyone. It is not designed to compete with detectors costing 2 to 3 times as much. It does take time to fully learn and that can't happen in a few weeks or even a few months for that matter. Yes, it will work fine from the getgo but to get the most out of the detector takes work, practice and patience.

Reg

Link to post
Share on other sites

I really hadn't planned on responding but it is time. First of all, I have a question for wjbell and that is, is that your TDI Pro for sale over on the Nuggethunting forum?

I'm not sure how that's relevent, or so important that you had to mention it first on your list, but yes it is... or was. I actaually sold it today and bought a GP3000. Like I said earlier, it's not that important to me who uses what detector. We should all use what works for us. Throughout my time with the TDI SL, TDI pro and using friends' Minelabs I have seen what they can do and which direction I want to head. But my original post was just my observations, and the observations of some experienced guys that have been doing this for 20+ years. As a guy in the hobby along with everyone else, I just want to share my experience on the forum so that it may help others.

Are you a White's tech guy? Just curious.

Link to post
Share on other sites

wjbell,

I do not work for White's and have no personal or financial interests in the company except to say that I do a lot of engineering work on detectors as many of the readers on this forum know. As it turns out I suggested a lot of ideas to Eric Foster and he provided a lot of technical information over the years.

So, when Whites purchased the rights to the GS 5 to design the TDI I was the person here in the US that was most familiar with the design. As such, White's asked if I had any other suggestions. Since then I have offered a few technical ideas and designs including the basis for the one that was added that reduces the noise on the SL. This is why I know exactly how that design works.

It is why I ended up with a prototype so I could further develop a couple of other ideas.

Over the years, other members of this forum such as Bill Southern and several others have seen some of my ideas including a low powered ground balancing PI I built for my dad to use because he could no longer swing his ML. Nothing like it existed prior to that design that was low power and could detect smaller gold than any other PI.

Now, one more item and that is using a detector for years means little when it comes to changing from a VLF to a PI. In fact, it can be a major problem because people expect the PI to act like their VLF's and it won't. So, time with use of a detector means very little in my opinion.

Personally, I would prefer to train a newbie on how to use a PI than someone who thinks they are an expert. The newbie is willing to learn. The "expert" knows it all or so they think.

Oh yeah, just for the record I own a ML PI and one of their VLF's along with about 30 other detectors, many of which I use from time to time.

Good luck with your ML.

Reg

PS: Just for the record, I began using detectors in the 60's and began modifiying them shortly after. Over those years, I have seen a lot of changes and as such stumbled into a lot of the mistakes people make. One of the biggest with VLF's was when the change came from the snake killers to the ultra slow motion machines. In bad ground failure to change sweep speeds led to big disasters for those wanting to find something.

Changing from a VLF to a PI is even worse.

Link to post
Share on other sites

Reg you have taught me MUCH over the years and remember the time years ago you used one of your modded Goldscan detectors to find a pin head size nugget under those power lines near Wickenburg? That was back when I was using a SD 2100 and couldn't hear that nugget through all that EMI no matter what I tried.

Few years after that and right before Whites got the GS5 I was helping with some field testing for Bill C. and Eric F.

Lot has changed since then especially in the PI world.....

Happy New Year Reg!

  • Like 1
Link to post
Share on other sites

Happy New Year to you Bill!!!!

Boy, how time flies. I didn't realize how long ago that was when I had to find my little nugget again.

A lot of changes have transpired over those years, all of which make nugget hunting easier. ML has made great strides reducing the noise that used to plague them so much. As we all know, a quiet machine is much easier to operate for long periods of time.

Anyway, I wish you and all the rest of the forum members the best for the up and coming new year.

Reg

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Recently Browsing   0 members

    No registered users viewing this page.

×
×
  • Create New...