Geotech

Now that I think about it, the GMZ may have used a Classic board design. I was thinking it was GMT-based but it was not. Dan Geyer designed it just for kicks and it worked pretty well, so White's decided to sell them. I think he took a Classic, bumped it up to 48kHz, and added a manual GB.

The PCB doesn't look like a GMZ, I think it's a Classic-SL.

I'd say the person who wrote this quiz is working a bit beyond their knowledge.

I exchanged a few emails with Richard early on and my impression was that he was the sole designer. The TNet "associates" gave input on desired features/performance and were to eventually field test the design, but it doesn't appear to have reached that stage. I don't think anyone was ever asked to pony-up any money. Some of the associates were adamant that this was going to be a game-changer. I never understood if they actually saw anything demonstrated or if it was all based on verbal promises. At this point I assume next-of-kin will figure out what to do with the thing, assuming they a

I had an unenforceable (badly written) 2 year NDA but even if enforceable would not have prevented me from designing a similar product, meaning a VLF pinpointer. Just not the same design. And since I did not write the TRX micro code, it would have been guaranteed to be a different design. But it still might have looked a bit dodgy so I chose a PI design to avoid any semblance of dodginess.

It's a good story, but not reality. I worked there, and still kept tabs after I left. Sales were falling continuously. Every time I dropped by, there were fewer and fewer cars in the parking lot. Yes, there was a couple of years quite a while back where sales in Africa exploded, then the Chinese counterfeits put a stop to that. The owners were irrelevant because they did very little in the company. Once upon a time there was talk of an employee buy-out but in the end there wasn't much for them to buy out.

What you see for sale is a bunch of older generic stuff that practically no one who might buy "the company" would want to mess with. What is not for sale is all the key equipment for making detectors. I suspect they are still trying to strike a deal on an overall sale. For the most part, there is nothing preventing a company from making the same detectors as White's was making. Replicating the circuit design is easy, but they would also need the micro source code. Source code repositories are on the company server with limited access so it's not a matter of anyone's "know-how," it's a mat

The last 2 items are the "PulseScan2" and the "GMT Super Pulse." The PulseScan2 is what I initially called the TDI-SL before it became the SL. So this would be a 1st build unit I probably sent Reg for his help in the SL design effort. The GMT Super Pulse has nothing to do with GMT, it is a TDI-SL intended for the African market that fizzled. I think we built 100 units and the majority were remanufactured back into TDI-SLs making this a very scarce item. It lacks the pulse delay and the conductivity switch, but the guts are standard TDI-SL. "GMT" is prominent in the name because GMT had a histo

Lee Harris owned it last, and I think he ran it for a very long time, maybe back to '79 when it switched from Long John Latham's. I would assume he got the rights to all the LJL articles since he often recycled them in later issues. In any case, most everything prior to 1978 falls under the 1909 copyright act which provided 28 years of copyright protection. You could renew for an additional 28 years but most likely none of the magazine articles were renewed. Back then they had to be physically registered and that would have been a lot of work for a magazine.

The "Sensational... 12T" -- I have one of those. There was another Texas company called Jetco that competed with Relco in cheap BFOs. "Jetco" was named for the owner, John E. Turner. Does anyone know where the name Relco came from?

Actually, the last pulse delay (11.5) is actually 15us. It was a last second change to better accommodate full submersion.

"Centreville Electronics Northwest" is actually Todd Marshall who ran the factory service dept for many years.

I expect Todd can, but not Centerville.

That has more to do with recovery speed than number of frequencies.

Yes, he will.