Jim. said:
I'm just wondering how the new SDC2300 handles basalt?
Jim & Kerrie
Bit of an update Jim:
I didn't sell the GPX but did end up getting a reasonably priced used SDC, not to use in basalt areas as such, but for other purposes. I did however take it out today to get a good few hours detecting in with it. I wasn't really expecting too much gold wise from this spot but it is a good little testing field as it goes from quite mild yellow clay, shale & a bit of scattered ironstone to orange/red clays, shale & heavy ironstone/red quartz then down closer to the creek to the more milder yellowish clay, ironstone, quartz & lots of volcanic rock I.e. basalt. There is also a nearby powerline just as a further test on EMI.
The SDC2300 passed on all fronts but does still signal on some basalt from bantam chook egg size to fist or bigger sized bits. While there is literally thousands if not millions of these rocks about the area I think I got about 8 that signalled on the SDC. Obviously these pieces would be of a higher iron content than the norm as they were all picked up in amongst other various sized bits of the basalt that didn't register. I've experienced similar with a SD2200D in the same ground although felt it was probably more prone to have a broader type signal on more pieces while the SDC signalled on fewer pieces but gave a harder to distinguish signal - faint on smaller bits & sharper on the bigger bits. The GMT I used in the area also signalled more frequently but also gave a more distinguishable tone on them. Haven't bothered trying the GPX there due to the powerlines but having used it in another basalt area I already know it will signal on a few odd bits here & there too - like the others. So thats 4 x detectors I've tried on this stuff with none being a stand out on it but the SDC2300 appears to signal on fewer pieces albeit without any really good, distinguishable tone on them.
I did also, after getting one piece of the signalling basalt, ping a sub gram bit of gold at about 3" deep right next to the basalt. After getting the gold out I got another piece of the basalt about 6" away so it would appear to me that the SDC2300 doesn't loose sensitivity when ground balanced in this type of ground. I have never found gold with the other machines in the basalt littered ground but have got some in the higher up mild, yellow clay area.
In short the basalt dilemma still hasn't been fully taken out of the equation with the SDC but for the amount on the ground here the positive signals are fairly minimal & I could still ping some gold which is always good.
Be interesting to hear how the SPP goes with a low conductivity switch added? I do have a feeling though that there will still be some of the high iron content bits that will trouble most machines. Reason being is although they signal they are still low conductivity targets in relation to their size. Thankfully they are big enough to easily identify & quickly kick out of the way.
