Looking For Whites TDI Mod Info

[machinesmith]

Here is the schematic of the mod that you asked for. Sorry its been years since I talked to Reg, he just dropped off the face of the earth around 2016 or 2017 and he stopped communicating. Hope this helps.

 

[Steve Herschbach]

Eric Foster is the guy whose name you can't remember who built the Goldscan, which was the basic design for the TDI. He died last year.

Reg Sniff passed away in 2020. They will both be missed. It appears you may have information that nobody else has now that they are both gone, so thank you for sharing it with us.

[Compass]

I thought that there would be a bigger reaction to this schematic but perhaps I'm missing something. The TDI Pulse Scan and TDI Pro have intrigued me for some time and now a Pulse Scan is on its way to me.                              My understanding is that this mod will smooth out a "warbly" threshold thus allowing the detectors to be operated at a higher gain for better performance. I'm no expert when it comes to electronics work but adding these additional components doesn't look too daunting of a task. However, would the detector need to be "calibrated" after the mod was done? If so, then maybe it is beyond my current capabilities. Perhaps I missed it but I didn't see any specifications for those additional diodes and resistor unless it's obvious to some of you by looking at the pictures?                Anyways, I find this whole subject of detector mods strangely alluring like some magical secrets only known to a few people.

 

 

 

[Cascade Steven]

Machinesmith

thanks for the additional information and schematic.  I am curious if these mods were included in the TDI SL at the factory?  Just intellectual curiosity.

[Jim in Idaho]

1 hour ago, Cascade Steven said:

Machinesmith

thanks for the additional information and schematic.  I am curious if these mods were included in the TDI SL at the factory?  Just intellectual curiosity.

Different machines. Only similar circuits, not identical, Mods on original TDI are not the same mods on TDI SL.

Jim

[machinesmith]

Steve,

Thanks for the update, and of course, you're correct. Eric foster was the guy who's name i couldn't remember (Jim Foster is the guy from Coiltek, lol, I messed that up), which is strange considering how much I talked to Eric and Reg over the years, but Eric met some girl according to Reg and went absolutely nuts over her and pretty much vanished, lost all interest in mods and fixes etc.... Im glad he found someone, but I was a bit miffed he stopped taking my calls and apparently Reg's too.

I have the TDI Pro Oz series... Previously I had the Goldscan 5C, but I sold that after I lost contact with Eric and Reg.

My TDI has been modernized since all those the old mods were done, and uses more modern parts now than we had access to back then. Technology really is amazing.

Even though I have a GPX5000, unless I'm literally out the middle of nowhere, I prefer the TDI because I can use a mono coil and detect right alongside a fence or directly beside or under a mobile tower where the minelabs can't even work. I don't have to worry about emi at all. I use the TDI because it just goes places where the Minelabs simply CANNOT get to because even using a DD with cancel activated on the minelab, its still nowhere near as effective as the TDI. Its just TOO noisy. The TDI aslo has excellent discrimination all while using mono coils. Thats why I'm partial towards it. I haven't tried the new axiom but I'd be interested to see how it performs against my old machine.   

Jim is 100% correct. Fow whatever reason (my guess the calibration with the analog timers, would have been the reason they moved to a microcontroller in the SL).

Is the code for it available ? I never worked on one at all, I knew it was being produced, but i wasn't involved with it, though at a guess I'd say a few of the fixes we did back then made it to the SL as it made a fair difference in performance.
But I'm not as familar with the SL as I am with the pro, I preferred the Pro version because it was completely analog and you could do so much more with it. But I'm pretty sure they would have left most of the primary stuff the same, so Im sure I could do some modding on that machine too.
Is there a schematic available for it ? I only have the Goldscan schematics, I can't find my TDI schematic.. Its honestly been years since Ive played with it apart from wiring in a different op amp than the one Reg used and making some changes to the audio section with more modern parts to help reduce noise. The goldscan was a great machine, but the TDI version surpassed it in a lot of ways. 

 

[Geotech]

On 11/30/2023 at 9:19 PM, machinesmith said:

Jim is 100% correct. Fow whatever reason (my guess the calibration with the analog timers, would have been the reason they moved to a microcontroller in the SL).

Except for the first 200 units, the TDI also used a micro. A micro is simpler and cheaper. I wrote the code for both and recently reconstructed the code to do some experimental work.

[karelian]

I've taken some images of a Tdi Pro Oz machine that was modified by 'Luke'. All I know is that the threshold is a bit smoother and there is a very very... small difference in performance.  Again for those who are interested I hope it is of some value.

I have no understanding or knowledge of what was done other than it relates to threshold smoothness and sensitivity.. for those who are interested, all the best. Selling the machine so it was a last opportunity to take some photographs.

[RickUK]

@karelian,are you selling all your TDI detectors or just this one as you had been possibly one of the most knowledgeable people on the TDI range especially with your coil knowledge and the tremendous indepth testing of about every coil going for the TDI range......must admit i would like to thank you for sharing all your help and advice.

[karelian]

Just selling surplus machines, but keeping my Tdi Pro for the beach. Finding more gold on my local beach than the actual goldfields and it is only a few minutes away by car... All the best.