tboykin

Reg - I will look into these. As far as the pulse delay, it's not possible to lower it any more than 10usec due to the processor speed. Swapping the processor will unravel the sweater, so to speak. But the other mods with a small folded mono coil should address the instrument's response to small gold. If we can do these mods cost effectively they are worth it, but it makes sense to invest more $ in new tech. The idea is to squeeze a few more inches/grams out of this machine before the next generation hits shelves. Thank you for your input.

We have our hands full here with some of our own projects. But if a QED showed up at the factory and ticked all the boxes I could put in a good word or two. After reading through the history of this project I would say I'm skeptical. But any advances in the industry are welcome, whether it's from the big guys or built in a garage somewhere. As long as it helps people find gold!

Brian that is very kind of you. We are the closest manufacturer to your neck of the woods and I hope to see you out there when I head down to NV next year! Initial test with a 14.8 volt battery (overcharged to 16+) showed the TDI SL within an inch of the PRO on nickel and larger-sized targets and neck and neck on smaller targets. This was with the stock 12" coil and also the smaller 7.5" DF. Wide open on both machines, GB off, delay of 10usec. But the SL was a lot smoother at full throttle. You can try it yourself for proof. I need to test it with more aftermarket coils like the MJD and Coiltek, but I would guess that results will be similar. You can make your own battery pack with a set of 4 18650's and some clever wiring but we hope to have a proper version soon. Such a simple change, and the bonus is it will fit all of our other machines that use that style of battery!

Looking forward to it. Quartzville is my second favorite place, first is Josephine County serpentine contact zone. My mom's side is from JC, used to spend a lot of time on River Rd, at the JC pond, and haircuts at the old barber shop in town.

Tested with 4 18650's.... Interesting results at 16+ volts fully charged. Eight cells is unnecessary (and too heavy).

The great thing about these changes is they cost very little and improve the performance enough for one last hurrah before the next generation of machines comes out.... if they were to come out. Maybe we will just re-release all of the classics! I have heard a lot about you in my short time here. You are a smart dude, and I would love to shake hands with ya some day. Next time you're in the valley let me know. As far as that platform I have no idea what you're talking about... Maybe it got boxed up and forgotten. Going forward our detectors will be bulkier, heavier, shallower, and have a shorter battery life than any other machine. Here is a picture of the next generation of machines from White's, it runs on forty 9v batteries and hits a nickel at 2 inches---

Rob, thank you for the suggestions. The SL can safely handle up to 16 volts, and I've tested it with higher voltage batteries with a good increase in performance. The issue with an 8usec delay is choosing a coil that can operate smoothly at that setting. Gotta go with a smaller coil at that low of a pulse delay. A small folded mono with a hot battery and 8usec delay... You will be closer to GMT-sized nuggets with that combo.

Rod, you could always head down to Armadillo Mining in Grants Pass (or another dealer) and find out yourself. I just mention Armadillo because Sam really knows the SL and is a multi-line dealer. She is way less biased than I am!

I appreciate the Aussie banter! Just looking to make the most out of a machine that doesn't cost big bikkies. I will look into why the mark-up is so high on our machines. Those prices are venturing a little too close to Codan levels.... Although it is good to hear you guys are back to using proper money after this....

Chuck, thanks for your thoughts. Over the past year I have learned that is best to wait until you have something that is ready to sell before hyping it up. I don't think there will be much for heavy-hitters (heh, heavy swingers I guess...) to be excited about until some kind of new technology is released. Otherwise it is just rehashing old ground. Pumping a little life into the TDI SL wouldn't beat a GPZ's performance. But it would give regular folks a chance to get into an easy to use, decent P.I. for not much more than a GMT. And you could take it places the Z would be too cumbersome to follow. Still a rehash, or maybe an improvement you could say. I will say this - if I post an ambiguous thread asking for testers next year, it might be worth getting excited about. But we will see what happens.

There are a few easy things we can do to improve performance, wondering what you think about them: 1. Include a hotter battery (with charger). This bumps up the depth closer to a Pro, and in practical, in-ground use (keeping in mind things like a smooth threshold/noise and target identifiability) it really is almost a wash with higher voltage. Talking an inch difference or so based on initial testing. 2. Replace stock coil with a different design for better ground rejection and sensitivity to small gold. Coil technology for the TDI series has come a long way in the past few years thanks to guys like Miner John. 3. Decrease weight even further and include built-in options for chest mount. This would make it the lightest pulse on the market, and ideal for backpacking in. Not a big deal for older guys who like to stay within a stone's throw of their car or ATV. But that kind of detecting isn't for them. I know for a select few U.S. prospectors money is no issue. But for the rest of the world things like weight, cost, and portability are bigger factors. If you are hitting the same areas that have been hammered for decades, obviously you will need the deepest, most expensive detector just to find 3 DWT in a week's time. The guys who are beating the brush (or freshly opened gold fields in Brazil, Africa, or OZ) need something that they can drop, scratch, pack-in, and will find them gold in harsh ground. The GMT struggles in areas like serpentine zones, ironstone, basalt, etc. My gut feeling is that the SL has a stink about it based on hearsay (not actual use), and that with a little bit of attention will make an excellent working man's pulse machine. The reason I wanted to ask you guys is I have been talking to SL owners and dealers recently, and they are quick to sing its praises. And these are people who use the machine regularly! The only knocks on it have been on forums and they say the same three things (which would be improved by the previously-mentioned list)- 1. Not as deep as Pro (insert other machines like GPX/Z depending on forum) 2. Not as good on small gold as VLF/MF 3. Doesn't work well in red-hot ground I think it's worth looking at and maybe tailoring it more to the blue collar guys who don't have 2k+ for a machine. Or a backup beater/slamhog detector for when you don't want to scuff up your shiny Lamborghini. There are a lot of great ideas in this thread, and I welcome more input. A lot easier asking the pros directly than shooting in the dark!

I will believe it when I see a nugget dug with it --- the QED has been on the verge of release for 6 years!

Thank you for this, will take this to heart and I hope to make it so next year.

I am curious what you guys think about the TDI SL. To start off - I KNOW it's not a GPZ! Price, weight, usability... it seems to have em covered as far as the under 1.5k pulse market goes. Maybe it's just under-marketed. Hope it's ok to ask here, I really appreciate what a resource this board has been for me in my first year at White's. I figure what better way to get an answer to a question than go straight to the folks who know best. So - let me know what you think about the ol' SL. Good. Bad. In-between. Open to suggestions.

WOW. Great pics!

Been getting into macro photography, here are some close-ups of nuggets found with a GMT in Northern California by the factory's own Steve Howard. What's your best nugget picture? Interested in seeing different photographic techniques... might steal some ideas from those with more experience. I know "size matters" so having a reference like a US Quarter is good, but I think there is a lot of beauty in seeing just the nuggets - texture, structure, color, that sort of thing.

Chuck Taylors are my shoes! Ah, gear. I used to work on movies and I must have spent $20k+ on custom workstations, monitors, mixers, microphones, etc. Tax time helped out a lot and I still use it for my second job which is doing sound design and mixing for commercials. I took a job at White's and told them I could bring my audio gear but they would have to buy a camera. When I lived in Los Angeles I worked with Panavision 35mm/16mm film cameras, Red, Alexa, and other traditional large-format cinema cameras with heavy primes. Of course I did a lot of gigs with lil' DSLRs but I just think they give a very "plastic" look and aren't good for handheld work. I remember on one set I saw a DP push a camera dolly with a brand new prototype Red camera with I believe a Canon CN-E 30-300mm... not realising the dolly track had not been "locked"... The camera and lens went sideways, there was glass and bits of electronics everywhere. I think the total bill for that goof was over $100k and the union was not happy. I like heavy stuff that can take a beating (and don't really like syncing sound) so here is what I use- Sony HXR-NX100 with Manfrotto sticks Sony NEX 5T for B cam when needed GoPro Hero Session 4 Sennheiser MKH60 (best shotgun mic IMO, very warm sound and low EMI response) Sennheiser G3 with PSC Millimic (prefer Lectrosonics but they are Minelab-level in terms of cost) Personally I would shy away from DSLR's. The audio is usually unusable (with few options for piping in good mics to the camera), the motion looks jelly-like, and any slight movement creates a very cheap image. Also, you had better be Johnny On The Spot with your focus pulls. The large sensors create a very shallow depth of field, which is pretty but requires a sharp eye, quick hand, and years of practice to keep objects SHARP. If you'd like to talk more about video gear please PM me so we don't clog up the board. Now back to your regularly scheduled programming related to inches, volts, and VDI...

That is true. I haven't found a way to make invisible soil yet, though I have a few ideas... I don't expect to convince anyone with a video like this due to a thing called "confirmation bias," but some people have asked for this kind of test specifically so I wanted to provide it for them. If you have any specific requests and there is a supporting demand for that type of video from others I will gladly shoot it. Up next I think I will do one on Audio Modulation and Sensitivity, since the two are related.

My $2000 camera, $1200 microphone, and $40 Chuck Taylors are not

How many nails can one machine take? I ran out - If you guys would like to see something specific for a video please let me know! I have a vial of nuggies I can use to show gold response next. But its pouring up here so I might have to wait for a break in the weather.

It depends on voltage, ground, and coil choice. A folded mono coil like the MJD will be more sensitive on smaller nuggets (and porous ones too). You will lose some depth, but using a "hot-rod" battery pack will help make up for it. I have seen guys use as high as a 14.8 volt battery pack for extra punch, which seems to get the SL closer to the Pro in terms of depth. In my own testing a modified battery holder (9 AA's instead of 8 for 13.5 volts) got me an extra 1-1.5" with the stock 12" coil on a nickel-sized target. Worth looking into further I think...

Very easy to modify it to a straight shaft (even carbon fiber). FWIW I prefer a hip/chest mount. Makes climbing cliffs much easier.

I think for the price you will not find a better pulse machine. But I could be wrong.

The Pro was a solid performer in terms of depth, though you had to fight the threshold to get it. The reason it is discontinued is the components are obsolete/prohibitively expensive. What improvements would you like to see in the TDI SL?

Currently that is correct.