I put a couple of videos up about the MD20 the other day. You may find them helpful. The thread is an old one about a hunk of rock I have and whether it might contain gold. I revisited the topic after getting my falcon recently.
https://www.prospectingaustralia.com/forum/viewtopic.php?id=3377
I have had it for about a month, and I like it's ability to find very small pieces of metal, not necessarily gold though.
Having said that, it is hit and miss as far as performance goes, though I haven't worked out yet if it is the way that I am setting it up, or if the machine is in fact the Anti-Christ.
The instructions say that it should work well if the ground balance and sensitivity are set to about 12:30ish, with the copper ring slid around the black and red line marks of the handpiece.
I still can't find a sweetspot anywhere in that range. It seems to depend on a mix of variables, i.e. the humidity on the day, if I am wearing my wedding ring, if the cheese on the Moon has melted.... etc. Some days I have to slide the copper ring down a couple of inches away from the marks, once I had to slip it off completely and let if hang on the cable....actually worked very well like that. But the next day it had to be slide back up closer to the marks.
Then you get the times when Satan climbs on board and it just won't stop sounding constantly, no matter how the set up is.
It isn't useful as a "pinpointer" IMO, it lacks the depth of an XPointer or ProPointer.
If the sensitivity is set at the low end it has a lot of tolerance and doesn't seem to false at all. In that respect it acts like a coin detector, sounding off on targets. If the sensitivity is set higher it develops a thresh-hold and you can hear the variation in pitch as a target is approached and recedes. At this level though, it doesn't take much movement or any nearby large metal objects from sending the tone into constant sound, and the sensitivity must be reduced to get the machine back to a neutral mode.
I have used it in the field, and it performed very well that day, finding one small piece of gold in a piece of stone / clay... but I mean real small, flour gold. Because of the way it works, you can discriminate on the basis of it's either metal or mineral. Anyway, it is only new to me and I have a lot to learn about it in the future. And it is only one of the tools available, so I won't be hanging my hat on it.
It seems like a sturdy enough unit, with obvious weak points though (the cable, the connection.... and don't drop the box in the creek!). If you get the belt holster, best you get a couple of rubber o rings to fit under the knobs to give them some resistance against inadvertent bumping against your beer gut (no offence meant).
My experience in actually coming to own one was not a smooth journey as some here will know. I tried one agent (not named) and just didn't get replies to my enquiries about getting one. That directed me to the infamous Brad from Aussie detectors. I wouldn't recommend his services to anyone. Had it not been for some advice for the kind people on this forum, he would have fleeced me good. I ended up ordering on eBay from Joey Wilson (
www.prospectingchannel.com). Took 11 days from the States to my door. My only worry will be if things go wrong with the unit, as there have been some horror stories about sending the unit back and never seeing it again. (fingers crossed it lives forever :lol: .)
Hope some of that make sense and helps you
TT.............ps. edited to advise sea sickness tablets prior to watching the videos.....TT Spielberg I am not :8