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.

It looks like a calcified fossil. Nice find man! It's quite beautiful

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.

We also changed some capacitors to reduce the response time of detecting a target, but it looks like he's shared that one. But i'm not familar with the newer machines. The original was all analog. The booster is basically a voltage increase for the detector, but rather than putting all the power through the detector, it just adds a bigger front end to the existing front end. The one i had was 24V-36V but in all honesty i don't recall it making a huge difference, probably took it from a 2100-2200 equiv to a 3500 performance wise or something like that. But that was before we'd done more adjustments on the machine too, so there is that. I didn't get much chance to test it, I was a bit worried at the power it was putting out... Its a giant transmitter, and yes, it finds gold deeper, however, it isn't legal here (or probably anywhere lol). And yes, he shared the schematics with me. I think his name was Jim foster, we talked a lot about tx rx stuff and i missed the chance to meet him when when he came from America to test his original goldscan prototype here in Australia. He was a nice guy.

I didn't know people were still modding these machines...! I could have given you the schematic of that mod. Its removing some of the additions that reg made when he converted the goldscan to the tdi. I found it was much quieter and reg shared the schematics with me and we worked out where the issues were. We also did some other mods to make use of more recent parts. But after his death I kept modding my machine. It only works in the original TDI prro machines. It removes some filters he had put in. I also have one of the boosters for this machine that uh, i forget his name, the guy that invented the Goldscan built. Its just a larger front end and the its the timing adjustments on the tdi that allow for it to work.