tight discriminate pattern experiment...

[Knipper]

I'm hesitant to ask this to many who favor all metal searching or something close to it, but here goes...

Back in the day with the old analog machines, when we were confronted with super trashy areas that we knew held good coins, we cranked up the discrimination quite a bit and sometimes even turned down the sensitivity. What we found was that, the machine, when not given a 'choice' as to how to respond to a target, would give good readable signals on coins in, below, next to and above the trashy targets mixed in the matrix. In other words, we set the machine so trash wouldn't respond at all. If there was even a HINT of a good target, we would get some audio or increase on the analog meter. It worked well under those conditions, even though the machine was 'nulling' most of the time.

In Andy's books, he mentions this several times as a means of dealing with super trashy areas, or testing areas that you want to initially cherry pick to see what's there, and determine the potential for the site. One type of site that comes to mind are old fairgrounds. There seems to be no end of varied and different kinds of iron and aluminum trash at these sites.

So, has anyone 'hit the gravel' and other super trashy areas with a tight pattern (basically programmed to allow coins only, entered through the "learn" function..) and found that when you tell the Explorer not to 'speak' unless it hits one of the programmed accept areas, you still get some signals through the null? Next time I'm out, I have such an area in mind to test this. I've programmed in some settings that are comprised of all my good 'keepers' over the years, including large cents, two center's, IH's , V nickels and even a few gold cons thrown in, and of course all silver coins.

I'm curious if anyone else has tried this...

Knipper

 

[Nick A]

Yes, I did something like this when I fist got the Explorer. The tones were overwhelming at first, so I used learn and set it up just for silver dimes and quarters. Worked like a pip, got a lot of quarters from trashy sites, quite a few silver coins and gained confidence in the machine and slowly kept opening up the discrim window. If I were doing this, to me, the most important thing would be to go slow, so those good sounds can filter through and you can hear them. You certainly have nothing to lose by trying it, that's for sure. I will be curious to see how well you do with it. I think it will work well.

 

[Chris(SoCenWI)]

is when I'm hunting a site with alot of aluminum pulltabs and more modern high conductive trash.

I usually hunt almost open screen, only have bottlecaps disc'ed out in the lower right hand corner. I run ferrous tones in manual with the sensitivity just before it goes nutty. And this works fine as long as the bulk of the trash is iron; which it is in most locals. I'm a firm unbeliever in tight learned-in patterns. They can work in relatively virgin areas, or if you are a claddist. Although this technique will occasionally get an more obvious signal in worked out areas(and hence why some people think it works just fine), for the most part the remaining goodies in heavily worked out parks are still there because they don't give a "classic" response and there is a low probability that it will fall in an area you learned in.

In areas with heavy modern conductive trash this doesn't work as well because one needs to keep looking at the screen and see where the target icon is hitting. Really slows you down. Instead of learning in targets I just disc out the bottom half of the screen, or even the bottom and left half and leave the right upper quadrant open.

Basically not worth learning in nickels, gold, and other lower conductivity targets. If you have lots of time on your machine you will probably have noticed nickels have a much bigger area of bounce than copper/silver. They can more easily be influenced by other nearby targets and mineralization. If you program in a small window that chances of anything more than a couple of inches down hitting in the right spot is quite slim.

And yes, if the undiscriminated target is a strong signal it will break the machine out of a null. Last year I was doing a neighbors house. Typical in town situation with powerlines nearby. I was surprised by how high I could run the sens and still get a good signal to break out from the pinball sounds of EMI from the powerlines. Twas a type one Standing Liberty quarter. However if the signal was a fainter one I doubt it would have overrode the noise. I think discrimination works the same, if the good signal is stronger than the nearby disced out target you may get an indication. I'm not sure if Minelab tweaked the algorithm so a higher conductor/low ferrous target is favored.

Chris

 

[dewcon4414]

Im one of those guys that do use an old coin pattern that works for me. I dont use it in worked out areas, just because for those locations its fairly simple hunting. In fact i used it in Florida this winter and found some things i just walked over or didnt get a signal on. I DONT use it all the time, but find it helpfull in trashy areas ive hunted before.... and like Chris said when the sounds just get over whelming or the EMI is so high. You can teach yourself to hunt anyway and get very good at it. If i find a location difficult to hunt I try verious things... change from Cond to Ferr, go manual from auto, use a pattern or disc out certain trash. To me thats what its all about ... improving your odds. With the Explorer there are several ways to hunt... once learned you can compet with the best of them. BUT... expect to loose some coins like Chris said and maybe even depth if in auto if you arent using an expanded pattern. Not all coins will sounds off at say a perfect 00-29 especially OLD DEEP ones. Also, you may find you are getting chirps and end up checking them with IM... that takes time.

Dew