14 inch Field Reports

A Field Report on the 14 inch DD

Coiltek elliptical and 14" DD results...(long) Posted by Steve in KB July 09, 1999 at 06:55:04

G'day All,

Returned this evening from a prospecting trip. Tried the Coiltek 14" DD for the first time and did a bit more with the elliptical coil. This was a different type of ground to where I'd first tested the elliptical coil. I recently posted the results of that trip, describing how I found a little over 13 grams of small nuggets in noisy ground in 4 hours wandering (Chaining it shortly afterwards produced another 6.1 grams, by the way).

Anyway, the ground in this last spot was generally fairly quiet except for the odd concentration of noisy clay and a fair few hot rocks. It was a patch where someone had done some scraping on a flat quite a few years ago. I knew some people who'd tried the spot since, using a Minelab 11" DD coil, but they hadn't found anything. Oldtimer workings are minimal in the area, with only the occasional test dig here and there and just the one shaft in the vicinity, a few hundred yards away. Thankfully, not too much junk!

I put on the elliptical coil for starters and it wasn't long before I got a good signal which ended up being a 0.8 grammer about 5" deep on a slope in a run of decomposed quartz about 30 yards from the scrapings. Another hour produced no more from this spot so I headed off skidding with the 18" DD to try for a virgin patch, but after a few hours I hadn't jagged a piece so went back to boil the billy and consider a change of tactics.

I decided to put the elliptical coil back on and try it on the scraped area. After about an hour, I'd already dug a few hot rocks when I got another signal that sounded slightly different and I knew it was a nugget when it started screaming when I was down a few inches. At 5" a nice little 2.1 gram nugget popped out. Another few hours produced a further 3 nuggets, two of them at about 5 - 6" depth and one 0.8 grammer at only 2".

Then I decided to change to the 14" DD and give it a go. The first signal ended up being a 1.1 gram nugget at 6". About half an hour later, I got a very faint signal and I dug down to almost 8" before it was out of the hole. I was astonished to find that it was only a 0.9 gram nugget! I found one hot rock with the 14" DD but it was on the surface. Dug about 12 hot rocks when using the elliptical coil and some of them were a few inches deep. The hot clay patches fooled the elliptical coil a few times but not the 14" DD.

By this stage I had worked out the boundaries of the productive area and was intending to chain the spot, but the upper body movement of swinging the coil was causing the loose plug connections on my old amplifier to crackle badly and the only way around it was to put the skid back on and spend the rest of the day searching for virgin patches.

But this weekend I'll be heading out there again, armed with my brand new Koss amplifier, to mop up the rest of those nuggets. The spot yielded 7 nuggets for 8.5 grams this trip. The size and depth of the last two nuggets indicated that I could have found all the others with the 14" DD, so that's what I'll be using when I return.

I really didn't think the 14" DD would have been capable of finding small nuggets that deep. That's why I was using the elliptical coil and putting up with hot rocks and noisy clay patches. Don't get me wrong, the elliptical coil is a little beauty, but I reckon with it and the 14" DD and the 18" DD on the skid, I've just about got all bases covered. The only thing I need now is a larger coil that proves itself to have a definite advantage over the 18" DD, plus a pinpointing probe.

Although I'll wait a few more weeks to make the decision, in case there's a niche for them that presents itself which I can't think of at the moment, I'll be selling my Minelab 11" DD and 8" mono coils. The only Minelab coil I envision hanging onto at this stage is the 18" mono, but that will also go if a more effective 24" DD coil comes along.

So if you see me advertising my Minelab coils for sale on the Treaurenet Forum, you'll know why.

Cheers,

Steve