TDI LOW DELAY

[eclipse]

The SL is just easier to produce - absolutely no critical trimmers to adjust. MCU controlled timings also don't need to be adjusted.
The LT1112 amplifiers don't need offset adjustment.
Matched gain resistor chip in the preamp to avoid exact value matching, single ended integrators additionally simplify things.
If the whole audio stage is made with a micro-controller this is going to be the best DIY PI in the world.

[Jim in Idaho]

Versions TDI before TDI SL deeper ? I would say based on the view schemes TDI pro and TDI -SL that it is deeper TDI course -sl is quieter .
Otherwise I was writing my hex code for TDI-SL starting at 5us up to 30 us ...

If you run the SL with a 4-cell battery pack, there's very little difference in depth between it and the other TDI's. And, the SL's smoother threshold probably compensates for that.
Jim

[Orbit]

If you run the SL with a 4-cell battery pack, there's very little difference in depth between it and the other TDI's. And, the SL's smoother threshold probably compensates for that.
Jim

You were comparing **?

[Rocketdemon]

So whats going on inside the new TDI Beach Hunter?

[Carl-NC]

So whats going on inside the new TDI Beach Hunter?

Should be identical to the SL.

[Jim in Idaho]

You were comparing **?

I have not done a direct comparison, but I know what my SL will do, and I have yet to see a video, or hear a discussion where a TDI Pro did any better. But, my SL is modded, to, so that helps. I also have read posts by Whites people that suggested in unmodified form, and with the stock 12v battery pack, there's only about 1/2" difference in depth capability. I know from my own testing that the 16v pack adds that much in an air test using a 1 grain gold bar. An air test isn't prof, but is suggestive.
Jim

[Orbit]

I have not done a direct comparison, but I know what my SL will do, and I have yet to see a video, or hear a discussion where a TDI Pro did any better. But, my SL is modded, to, so that helps. I also have read posts by Whites people that suggested in unmodified form, and with the stock 12v battery pack, there's only about 1/2" difference in depth capability. I know from my own testing that the 16v pack adds that much in an air test using a 1 grain gold bar. An air test isn't prof, but is suggestive.
Jim

Thank you Jim!

[Jim in Idaho]

Thank you Jim!

You're very welcome, of course. It may be that Daverave's TDI is better yet, with his 8us delay. At some point, I'd like to have a TDI to fool around with.
Jim

[green]

I have not done a direct comparison, but I know what my SL will do, and I have yet to see a video, or hear a discussion where a TDI Pro did any better. But, my SL is modded, to, so that helps. I also have read posts by Whites people that suggested in unmodified form, and with the stock 12v battery pack, there's only about 1/2" difference in depth capability. I know from my own testing that the 16v pack adds that much in an air test using a 1 grain gold bar. An air test isn't prof, but is suggestive.
Jim

1grain gold bar or 1gram gold bar?

[Jim in Idaho]

1grain gold bar or 1gram gold bar?

1 GRAIN

[green]

1 GRAIN

Where did you purchase it? Found a site that sells 1gram bars but didn't find one that sells 1grain bars.

[Jim in Idaho]

Tell you the truth, I don't remember. I bought it several years ago when I started doing testing of my TDI SL with various coils, and the higher voltage battery pack. The card it's on is a "Certificate of Authentiicity" for whetever that's worth. It says "Proud members of, Jewelers Vigilance Committee. The bar is roughly 3mm x 6mm.
EDIT: It took me 30 seconds to find them on Ebay. For some reason, I couldn't post a link.
Jim

[daverave]

all you need is an early TDI or goldscan 5 to experiment...its really the coil thats important to get a low delay...i have used mono coils to get the extra depth but would like to try a dual field coil sometime in the future...hope you can get a early TDI and do some tinkering Jim.

[Jim in Idaho]

all you need is an early TDI or goldscan 5 to experiment...its really the coil thats important to get a low delay...i have used mono coils to get the extra depth but would like to try a dual field coil sometime in the future...hope you can get a early TDI and do some tinkering Jim.

Thanks, Dave, me too! But, I've always got so many projects going on , it's hard to find the time. I'm going to keep causally looking for one, at a price I can afford. We'll see how it goes. I hope you can find a 12"DF, too. You've got some good insights into these detectors.
Jim

[green]

Tell you the truth, I don't remember. I bought it several years ago when I started doing testing of my TDI SL with various coils, and the higher voltage battery pack. The card it's on is a "Certificate of Authentiicity" for whetever that's worth. It says "Proud members of, Jewelers Vigilance Committee. The bar is roughly 3mm x 6mm.
EDIT: It took me 30 seconds to find them on Ebay. For some reason, I couldn't post a link.
Jim

Thanks for the reply. Was thinking 1grain of gold would have a time constant 1us or less and would be hard to detect with a 10us delay. I had looked at a couple sites that sell metal, didn't have 1grain gold bars. Like you takes about 30 seconds to find them if I search for 1grain gold bars. Some times I over look the obvious when using a computer. I keep wondering if I haven't asked you the same question in the past, apologize if I have. Found a formula that I had written down, calculates 2.5us time constant for the 1grain gold bar(3x6x.186mm). Maybe someone could calculate the time constant for a 1grain gold bar. 2.5us time constant would make it easier to detect.