I have found alot of detectors on the used market at fair prices but not sure if I should by one. I know laptops, PCs, cell phones and other electronic items are quickly out dated these days .....
.... There has been no real change in single frequency VLF metal detectors or their ability to discriminate since 1985. Machines have gotten lighter, coils have become better.
Terry's answer is spot on. That unlike the light-year's of evolution seen in the decade of 1965 to 75, and 1975 to 85 yet ... since then the progress slowed way down. In those prior years , you had a DINOSAUR if your machine was a mere few years old. But notice now, that various 10 or 15 yrs. old machines are every bit as capable as what's currently offered.
So ever since the mid to late 1980s, the only things coming out are more whistle and bells, and only *slight* improvements.
The reason is, that your analogy to laptops, PC's, cell phones, and other electronics, is lacking in comparison. Yes it's true that those things shrink every year, and double capacity and speed every few years, etc.... But those are all just functions of "smaller and faster".
The same can not be said for md'ing ability. Because of one big major problem: The impediment of the ground we must see through. And NO AMOUNT of "smaller and faster" can change the laws of physics. There is only so much information you can get out of signals bounced into and out of the ground. So unless some new method of what we're pumping into the ground (and what we're deciphering on the receive end) comes out, I'm afraid we're at a standstill.
Unlike the changes of BFO to TR, and TR to VLF, and VLF to MF, and pulse vs VLF, etc.... Those are all "new mousetraps", that yes, pushed us light years ahead. And sure, some nickel and dime improvements come within each of those. But at a certain point, you've reached the laws of physics, and no amount of 'smaller and faster' is going to change that.
There would need to be an altogether new system of detecting technology. NOT just "whistles and bells" added on to the older machines. Assuming of course, we're talking something of the last 10 or 20 yrs. For a machine from the 1980s to be still relevent and competitive, it would be something of that era like certain Teknetics, perhaps the Fisher cz6, perhaps the 6000 Di pro, etc.... Others from the 1980s are indeed "dated".
