Thanks PhaseTech that's good to know. My experience with the machine is limited.
Wednesday 13th September
I worked around 'Three Spikes' and down into Scorpion Gully. A very windy day with frequent showers. The SDC was the same as the other day. I poked around different heaps. I was happy enough as I was still picking up shot in areas that I had already done back in November/December with the Eureka. I was impressed with the fact that the SDC was unaffected by the hotter heaps. Half way through the day this generated an idea. During a rain delay I would go back to Mystery Reef and do the heap next to the one that had produced all the specimens. It has similar rock types on it but it is a bit hotter than the one that has produced all the results so far. There are more hot rocks and spots of pink clay here and there. The Eureka struggled a little on this heap due to the varying mineralisation I think. Right near the base of the heap I got a variation in the threshold. I thought it was just from moving off the slope onto the flat area of natural ground. Coming back from the flat to the slope of the heap the variation of threshold was still there. I scraped and scanned just the slope part of the heap. Yes a definite target. I'm sure I had covered this heap well with the Eureka but it had only produced a few bits of shot. Any way as I dug down the target got louder and louder to the point of almost an overload or blanking of the signal. It has to be trash being that loud. Down to dust and I could see a clear show of gold. A nice clean piece. My biggest bit yet at 0.302 grams.https://www.prospectingaustralia.com/forum/img/member-images/628/1505721566_sdc_0.302g..jpg
So only my second time out with the SDC and a personal best from a heap done with the Eureka. Going over more of the heap produced some quite deep bits of shot. Time to retire the Eureka some would say. But today was not suitable for a head to head test as rain threatened all day and once again the Eureka stayed in the car. I was impressed at the depth and wondered if the Eureka would have found this piece or had I already put the Eureka over this spot and dismissed the signal as ground noise. Lots of unanswered questions but any day finding gold is a good day. What about the Eureka. Well that story is coming.
Cheers Bob.