A good read - White’s MXT Engineering Guide

[www.detectorprospector.com]

Dave Johnson’s work and still a model of clear and open description of how and why a particular detector was designed.

Dave is about the smartest person I have ever met, and I have been fortunate to have known and worked with some pretty bright people. He has been “Chief Designer” (or whatever other title he chooses) at First Texas in El Paso for a long time now.

I started reading the paper and was struck up front by a couple of things.

The MXT has an autotracking system. No detector made by FT has one And Dave has written that he abandoned that for the “track and grab on command” type - usually called “ground grab”. It will be interesting to see what future FT units have.

The other thing in the early part of the white paper was this.....

‘During the fall of 1999, we decided to tackle the problem of desert heat head-on. A lot of gold prospecting is done in desert heat in full sun. I set up a crude but effective, thermal engineering laboratory, measuring the temperatures reached inside housings of various configurations and colors in full sun. Then began the task of finding an LCD, which would handle the heat. Because the LCD display is an important feature of the MXT, we revisited the whole issue of display. The manufacturers of LCD display had expanded their product offerings. We found a larger one, and changed the mechanical design of the MXT to accommodate it. A FSTN 0160 F was selected, (There are more to choose from nowadays, so we used a bigger one than the GMT in the MXT.)”

Given the screen fade in heat problems of the Nox, somebody in OZ ought to have read this.

Thanks TNSS

Rick Kempf
Gold Canyon AZ- where there is no gold



Edited 1 time(s). Last edit at 09/20/2018 09:47PM by lytle78.

One thing Dave could use right now is another " Hit" detector.

lytle78 Wrote:
-------------------------------------------------------

>
> Given the screen fade in heat problems of the Nox, somebody in OZ ought to have read this.
>

Yes Dave Johnson is a very intelligent engineer, as is Carl and a few others FTP have on staff. This is why it befuddles me as to why they haven't come up with anything that interesting in the past ten years.

Haven't heard of this knock against the Nox, and I read most posts here and on a few other forums Nox related. I recently spent five days in the Nevada desert with 100F temps using both my Multi Kruzer and Equinox 800, and didn't experience any issues with the LCD display, so I'm curious where this info originated?

Cal, here’s a few

[www.treasurenet.com]

[metaldetectingforum.com]

[www.detectorprospector.com]

Now displays going dark due to overheat are not unusual. Have to wonder however how that tiny case, crammed with active electronics, sitting on top of a lion battery will hold up in the long run with high internal case temps.

As far as FT’s lack of new stuff - well may you wonder. My pet theory is that they see multifreakers as the way forward, but that it’s a darned tough nut to crack. ML has the most experience, yet the Nox is arguably just a light, great value for money, fast processor, waterproof iteration of their basic multifreaker approach. No doubt there is some new processing going on, but it hasn’t - apart from its price, weight and waterproffness - made any stunning breakthrough. Not criticizing the Nox - I’ve got one - just trying to support my thesis that doing something truly NEW in our little world is darned difficult.

Rick Kempf
Gold Canyon AZ- where there is no gold



Edited 1 time(s). Last edit at 09/20/2018 11:43PM by lytle78.

Thanks Rick, I'll take a look when I get home from work and try to read Dave's MXT write-up. I've emailed with Dave over the years, very nice guy, and he tells it like it is, and I appreciate that.

I didn’t mean to make it a big-time “knock on the Nox” - just thought it was a bit ironic. I have demonstrated - to my own satisfaction at least - that Minelab outsources their mechanical design. That ain’t the high road, but it gives you dramatic designs - like the SDC and theGo Find - dramatic, but sometimes darned impractical for our work.

Dave and I once had an email back and forth about Swedish and Norwegian farm girls’ technique for calling the cows back from the woods - called (in Norwegian) kulning. My now deceased mother-in-law from North Norway was good at it. Dave came back with an analysis of the phase and pitch shift of the vocals and the highly effective transmittal of a low bit-rate message through a forest landscape with high attenuation and multi-path issues due to tree trunks, limbs, and foliage. Wow.

[www.deezer-blog.com]

Anna, my mother-in-law didn’t have an easy life. Growing up on a tiny farm in arctic Norway - 6 German soldiers living in the downstairs kitchen of their house from 1941 - 1944 (they were perfect gentlemen, she said, till they got rotated out and a bunch back from the Russian Front showed up - not so nice). Later a widow with two small kids, Whenever there would be a more or less serious problem, her response was always - “Det er ikke ei ku” - “It’s not a cow”. Cows were vital .

Rick Kempf
Gold Canyon AZ- where there is no gold



Edited 3 time(s). Last edit at 09/21/2018 12:07AM by lytle78.

The MXT Pro with the 8 x 6 SEF search coil attached is a formidable detector and is super fun to use. Dave Johnson did a great job designing this one.


tabman

Rick.as always, with some interesting worldly info---Thanks.