Geotech

Pulse delay & Frequency are 10k, although 100k will also work. Gain is 50k. Ground balance is 100k. Threshold is 100k. As I recall the PCB is marked where everything plugs in.

If I read it right, someone posted that the single F modes were the same as the Eq. But the Eq MF modes use different frequencies than the SF modes (2.6, 7.8, 39) and I suspect that 2.6 is for ground analysis. If I were to guess then I would say it's expanded on the low end to favor deep silver. Maybe there's a new boosted 1.56kHz component. That would also explain the incompatible coil. But then, I would also expect to see a lower SF mode, maybe 2kHz.

Most any coil that will work on a TDI/GPX will work on the AQ. A potential problem is that a lot of those coils may not work down to 7us. I once put an AQ coil on a TDI and could then run the TDI down to 7us, but with the stock TDI coil 10us was the limit.

Generally whatever you can do in time-domain system you can do in a frequency-domain system, just differently. You could determine target ferrousity in MIQ by looking at phase linearity through the response so I wouldn't be surprised to see that the Manticore does FE/CO with much the same waveform as MIQ. Also, it's difficult to mix simultaneous MF with sequential MF due to signal discontinuities that will screw up the channelization filters in the simultaneous side. Probably you could hook up a BFO coil to the Manticore and it wouldn't physically burn it up. I took Tom's comment to be more tongue-in-cheek than literal. A typical VLF TX coil current might be in the 100mA range yet battery current may only be 25mA. This happens because the coil is resonated with a capacitor and the TX energy is mostly recycled, with the periodic energy loss due mostly to coil resistance. This is obviously true with a sinusoidal TX but it is also true with a square-wave-ish MF TX. With an ideal coil (R=0) the power delivered to the coil is zero even if the TX current is 100mA. So when someone says "this TX has 50% more power" I don't know what that even means unless it's a total-loss PI transmitter. I assume ML's "50% power" statement actually means 50% more current which also means a 50% higher voltage drive. I think Tom mentioned this results in only a 7% depth increase which is right assuming a 6th power signal loss, which is close. But, hey, 7% is 7%. The V3 had a TX Boost option which kicked the TX drive from 10V to 30V, a 3x increase. This added about 1" of depth to most coins but cut battery life in about half because the TX coil resistance wasn't all that good. And in an MF detector (and really, any detector) TX coil resistance determines the lowest practical frequency you can run due to power losses. This could be why the Manticore's coils are different, they focused on a lower R to run a lower frequency and/or higher drive voltage. Although MIQ runs at 2.6/7.8/39kHz the 2.6kHz component appears to me to be weak and is probably mostly used for ground analysis, not target detection. That's why BBS/FBS was better for deep coins, it was dominated by 3kHz. So if Manticore can run a much stronger 2.6kHz you'll see deeper coins. On the display... It appears to me that the manual brightness goes down to 1 but not 0. This suggests that the display is a transmissive type which (like most cell phones) always requires some level of backlight or you can't read it at all. The CTX and V3 used a transflective display which was sunlight-readable even with the backlight completely off. But very few companies make transflective displays because, in a showroom where sales are made, they tend to look washed out next to an eye-popping transmissive display. Transmissive displays obviously chew up more battery power and any color display is far worse than the near-zero power of a segmented LCD such as used in most detectors. So the Manticore is going to have a higher batter draw just due to the display.

Brightness is now fixed but you can turn it off.

I would start with Todd at Centerville-NW. As I recall White's ran out of the exact displays several years ago so if Todd doesn't have them poke around DigiKey, Mouser, or eBay. There are several compatible displays that more-or-less should be an exact fit. They run $10-15 each.

To clarify on Aureous' post, I modified a TDI to test out an idea I had, it was a lot easier than trying to mod an Impulse. To do this I had to write new micro code from scratch. The idea worked but needs more effort. The code includes a switch to exactly replicate the original TDI timing and I sent a few chips to someone with a bunch of dead TDIs but he says the chips were acting squirrely so, again, needs more work.

Nothing White's had while I was there.

The TekPoint & F-Pulse are identical except for color.

The "New & Improved" is a matter of opinion. I made some minor tweaks to the circuitry to improve consistency but was also asked to remove some features and change the interface to make it simpler to use. Personally, I don't think it's any simpler and I particularly liked the Turbo modes that are no more. Also can't do audio-only any more. Otherwise, it performs the same as before.

For your purpose the Gemini has 2 major drawbacks. First, it's a classic TR design (not VLF-ground balancing) so it is more affected by soil mineralization. Second, it runs at 82kHz which is even more sensitive to mineralization. So it may have problems inside a cave. Probably a better choice (if you really want to use a 2-box style) is the TM808 which is a VLF-GB design running at 6.6kHz.

Yep, the missing components were for a bipolar version. Alexandre was convinced that this was the best approach but I convinced him to consider an H-bridge drive which is what he is now playing with. There is a way to use a twin-coil drive to cancel salt but I don't think that was his intent. Rather, it naturally cancels EFE and allows you to run a higher pulse rate.

Battery is 76WHrs, so it's 330mA@14.4V or 660mA@7.2V.

From Brent's exploded view it looks rain resistant but not waterproof. Doesn't look like anything White's was working on. Looks like it uses a 4-pin microphone-style connector. This means it's not compatible with older Minelab coils but on the bright side it means the coil isn't chipped.

Any rumors on pricing?

JP is right. The TDI-SL was specifically designed as a $1000 detector for the African market. Lightweight, cheap, and ran on AA's but fell a bit short in sensitivity. When we pitched it to various people in Africa the only question we ever heard was, "Does it go as deep as Minelab?" It did not, so we then sent a bunch of free detectors to Africa in the hope that some people would find gold and it would kick-start sales. Never happened.

Yeah, I agree, I think the TDI is at the end of the road. I had designed it with some hooks for ground tracking & performance upgrades but the ATX is a better platform. To Tom's post, one day I would like to see half-sine make it at least to field testing. I think it has a lot of potential. Yup, agreed.

And a Garrett coil. This thing sells for $850 on Ali Express, can't imagine there are too many people willing to pay that much for very questionable performance.

I think it began with the Lobo ST. The Cortes, deLeon, Golden, Tejon, Vaquero, Cibola, and Sandshark all have digital audio. Not sure about the Tiger Shark or Silver, never had one. Compadre was likely still all-analog.

All the last-generation Tesoro designs had digital audio.

I can't speak to what coils might be available. The only ones mentioned so far are the 8" (stock, I assume) and a 12", both solid disc style. There is nothing to prevent aftermarket coils but they are difficult to make and with a much smaller market share we'll see if anyone jumps in. But right now we need to finish the design and then see if FTP can manufacture it.

No,we will at least build out the remaining 40 or so we have parts for and then decide where to go with it.

The beach version is what Alexandre had focused on and was ready first. It did not have the small sensitivity of the (e.g.) SDC2300 and we didn't know how tough that would be to solve. Turns out dropping delay from 7us to 3us wasn't as hard as I feared, although it remains to be seen if FTP can manufacture it.

It is light and a breeze to swing. No idea on the price, that hasn't been decided yet. I've lobbied for $2k. No discrimination, it happily finds those rotten can flakes. In most places I did not find the manual GB to be an issue. But in one locale the ground varied by the meter and I found myself tweaking the GB every few swings. Once I swap the locations of the fine/coarse knobs then it will be fairly easy to use the thumb to tweak the GB control on-the-fly. As I recall, the QED has to be placed in a particular mode to adjust GB which makes it difficult & tedious. Impulse GB works in any mode.

It's strictly manual, no grab. GPX coils might work (I haven't tried it yet) but you won't get the minimum delay of 3us using them.