Geotech

I had a GTI2500 a long time ago. I used it once relic hunting with the 12.5 imaging coil, it's the only detector that has ever injured me. It was so heavy that, after a 1 day hunt, my shoulder had a sharp searing pain and I could barely sleep that night. However, at the time (15 yrs ago or more) it was the deepest all-metal mode detector I had ever used. Disc mode, not as impressive. I eventually sold it. I had, and still have, the 2-box attachment for it. I remember testing it and not being very impressed with it. The best 2-box I've used is the TM-808, which is probably a rarity now that White's has closed. It's one of the few models I think Garrett should strongly consider producing. A better choice for void detection is the Discovery TF900. Good luck finding one of those.

FBS is the same as BBS. V3 MF was never patented. I doubt Apex used BBS tech. The rumor is*, NM named it the Lightning because, instead of a vibrate option, it has a conductive handle that delivers an electric shock when you go over a good target. Especially noticeable when hunting in salt water. *Because I'm starting the rumor.

I don't think it's heat build-up, one unit failed on a cold start-up. I think is a bad solder joint on a chip where thermal cycling eventually breaks the connection and... pfzzt.

I'll tell you what I know, which ain't much. I have no idea how an AQ ended up in India, maybe FTP sent it or maybe he got it through some back channel. But that YouTube channel isn't run by FTP, someone else created it. Also, the website & Facebook page Steve mentions don't belong to FTP. I'm pretty sure the website belongs to Alexandre. A problem has developed with the AQ Ltd in that a voltage regulator has burned out in 3 customer units. Production is suspended until the problem is identified and corrected. They wanted El Paso people to do the analysis but that has not yielded any results so I'm hopeful Alexandre & I will get some material to analyze. Meanwhile, the mechanical design has been changed to eliminate the external battery pack and put the batteries in the tube. Probably when the AQ goes back in production it will be with this scheme and the Ltd will be done. I agree, this whole thing has been poorly executed. Sorry, wish it had been different. Wishing is about all I can do these days.

The 16V limit applied to the TDI, some people probably assumed the SL was the same. They are different designs. The FQT7N10 are FET transistors, used as reverse battery protection. Unfortunately I see they have a max voltage of 25V. It is not an easy matter to find a higher voltage rating, but would be easy to hack the board to reduce the voltage by splitting R41. It will require some documentation and photos and my SL is indisposed at the moment. Meanwhile, anyone intending to run the SL above 20V I recommend swapping some caps. They are: C2, C4, C5, C8: 1000uF@35V C33, C34, C35: 100uF@35V These are probably SMT and are buggers to get off. There are a couple of 16V caps in the audio stage but they are on a regulator that maintains 11.2V regardless of battery. I did that so audio volume remains the same if you use a bigger battery.

The original TDI was limited to a max battery voltage of 16V. I designed the SL so it could take 20V and will probably be OK up to 25V. That's the rating of the power supply caps and anyone not comfortable running caps all the way to their rating (I'm not) can swap them out for 35V caps. The next limitation are the voltage regulators which have a max rating of 30V.

As I recall, XP was the first to have integrated wireless headphones in the GoldMaxx. They were/are proprietary. White's was second, also proprietary. Then Garrett, proprietary again. Minelab's first wireless was also proprietary. And the non-integrated AirHeads were also proprietary. All this because e.g. Bluetooth of the day had too much latency. There was no other way to do it. Then CSR introduced Bluetooth with AptX-LL which has low enough latency to work with detectors. Minelab adopted this in their new wireless. I think some others have as well. And the latest BT 5.2 has an integrated low-latency audio that beats even AptX-LL. So I expect going forward detectors will move to BT 5.x. Meanwhile, those old detectors with proprietary wireless are what they are, and there's no fixing them.

If you still have a problem with disc shift then a worn pot can definitely cause that in the Tejon design.

It's not a "4.7," it's a "Y.7." This means it's pre-release beta software. The only released version was 1.0, there were no updates.

White's wireless HPs use a proprietary comms protocol. Nothing else will work.

I wish I weren't the only person at FTP reading this thread.

GB = 50k (I've also seen 10k) Sens = 100k Thresh = 100k Disc1/2 = 100k VCO - don't know that one. Pots are often marked, you may have to pull them to see the markings.

You can't change the password without help from the "factory." Since the factory is closed, that's now either Garrett or Todd Marshall. I'd put my money on Todd.

I know how to create new programs, but you are correct. It's not top secret, it's Top Secret. Shhhh, don't tell anyone!

If you know how to create a new program, then you know how to get Top Secret access. 😉