|
Title: dissapearing signals Post by: david995 on August 05, 2014, 09:10:42 AM I'm finding there are a few targets that get a signal with the detector but not with the garret probe.
outwardly appears to be a kind of hard plastic but obviously can't be if being detected by the detector , so my question is what can give a signal to the detector but not to the prope ? might explain a lot of dissapearing targets ( as well as the usual dropping deeper in the whole so out or range or the halo effect broken etc Title: Re: dissapearing signals Post by: Chef Geoff on August 05, 2014, 10:55:48 AM Where about on the smart screen does it register David?
Title: Re: dissapearing signals Post by: david995 on August 05, 2014, 02:59:10 PM hi geoff , just checked now , its right at the bottom and dead centre of the smart screen but it does nt make the BRRRR low sound you would expect from there but a mid tone like you would get if gold or lead ( im on conductive sounds ) ??? very iodd
Title: Re: dissapearing signals Post by: Val Beechey on August 05, 2014, 03:33:35 PM David, have you double checked the hole after removing the suspected target. Could be there are more than one item in the hole and you haven't quite reached the one that registers on the detector.
Also check sides and spoil and shovel. Val p.s. Had another thought about mineralised ground. There are many Iron Ore seams throughout Wales. I had a couple of fields that kept registering iron by the bucket load. Even tried digging some but never found anything. The land owner told me about the Iron Ore mining back in the 1700/1800's. If that's what was there it made detecting almost impossible. Could be you have the same problem. Title: Re: dissapearing signals Post by: david995 on August 05, 2014, 03:39:45 PM hi val , i have recovered the items but they don' t register on the prope but do obviously on the detector
the nulling is because the ground has lots of small iron, its red soil caused by the iron i have around 15 farms affected like that, so not a one off other farms i have are fine no problem Title: Re: dissapearing signals Post by: Val Beechey on August 05, 2014, 03:49:51 PM Sounds like very old ground that hasn't had much cultivation. I've got an old farm like that. Was sold about 3 years ago and the new owner ploughed all the fields. 1st time in a life time, or even 2. I think. I could see patches the red soil especially in one field.
I seemed to have double trouble there because I found chunks of very old charcoal and slag, which indicated Iron working. Combined with the age factor it made for very hard work and little to show for it. We live and learn. Val Title: Re: dissapearing signals Post by: david995 on August 05, 2014, 04:18:50 PM some of the problem farms have been ploughed a lot its just the solil im afraid ,
i see from other posts they have a similar problem in areas in the usa ie red ground same problem lots of nulling as geoff has said only answer is to lower sensitivity and gain and smaller coil or go all metal , the other way is to have a machine without the sensiivifity of the explorer and not be aware your missing lots of good stuff when the machine is nulling !! |