A thing of beauty it ain't, and it ain't got the hots and features of a $500 machine. But, what it does, it does very well. I've occasionally told the boss "Y'know, I could redesign it and....." the boss cuts me short and says, "First, show me an unhappy customer". There are people on these forums who have high-end machines in their arsenal who got started with a TK4 and won't let go of it, they still keep it as a backup machine and loaner.
Since I came to work here in 2003 I've re-engineered all our products but that particular one. It's the one the boss won't let me touch, because "if it ain't broke, don't fix it".
The variable phase tone discrimination system that's proven so popular on our new Gold Bug Pro and Tek G2 machines, was adapted from the TK4 because so many past and present TK4 users reported how desirable that feature is. Features on new products are usually trickle-down, but that one was trickle-up.
I used to know a guy in Colorado who tried to get into metal detecting and bought (sequentially) several medium to high priced metal detectors, and never learned to like any of 'em. So he gave up. His wife saw how disappointed he was without a metal detector and got the crazy idea of buying him a cheepie TK4 for Christmas, just to give it one last shot. Well, he tried it out, and it clicked with him. He used it in parks and schoolyards where lots of depth is useless since you can't be digging deep in those kinds of places, what you have to do is to beep and dig shallow stuff and ignore the trash. He learned every sound the machine made, and pretty soon was cleaning up. Every now and then he'd run into someone with a high-end machine and follow in their footsteps cleaning up more than what they were finding themselves, teaching them a lesson or two, even ID'ing their targets for them by ear with his TK4 (they had computerized target ID machines). He told me that his helpfulness somehow failed to earn him any new friends.
The TK4 is a good machine. You may eventually get hooked on the hobby and start spending a lot more on metal detectors, but the TK4 is an excellent way to get started. May not be pretty, may be priced cheap, may not be high horsepower, may have no newfangled stuff, but -- it's survived over the years because some basic stuff was gotten very right. The things you learn on a TK4 are adaptable to future higher performance machines you may move up to, because the TK4's design teaches you to pay attention to the sounds and to dig targets that sound good. Most of the high end machines have a lot of fancy features including computerized target ID, but those features can't replace basic beepering skills, and the TK4 does an excellent job of teaching you those skills. It's no miracle that so many people who are using $1,000 metal detectors now got started with a lowly TK4 and they still have it.
For all this talk about what a great product the TK4 is, I didn't design it, didn't even get permission to redesign it. Heck, I don't even know who originally engineered the thing, although I suspect it was the legendary George Payne. I speak highly of it because it has stood the test of time as a very good product. Given its lack of beauty and its low-tech flavor, I'm not sure why people who are unfamiliar with metal detectors even buy the thing, but they do. A lot of 'em. And I'm glad they do, because (as I already pointed out) it's almost impossible to find an unhappy customer. .......That's extremely important in this business where margin is only a few dollars and all it takes is one customer return or having to deal with one customer problem to erase the profit from selling a whole stack of the gizmos.
BTW, the meter isn't much more than a hood ornament. I recommend don't spend a lot of time trying to figure it out.
And, Merry Christmas!
--Dave J. (chief engineer of FTP-Fisher, manufacturer of the BH product line)
PS: A few forum old-timers have seen me spend an inordinate amount of time posting on what a great product the TK4 is. It's not like those posts are going to drum up a huge pile of sales, since most TK4 customers are people who never saw this forum or for that matter any metal detector forum. And, there are products I could brag about that I designed that made the companies that manufactured them a lot of money. The TK4 is an odd duck: the lowly beeper that I didn't design, that I wouldn't have designed, and that doesn't really click with me personally........ that I still have to get excited about because it is such a good product from the standpoint of customer satisfaction and because we're the company who makes the darn thing.