Hi Au.
I hope you really get to like your unit. Only one other comes close, the 705 when set up correctly.
I'll have a crack at your questions for sure, just bare in mind that what I say suits me 100%, and you may like to set up or detect quite differently once you get the feel of your unit and how you like to go about things.
1.
If you only have the stock 10x5 then I'd definently only start detecting an area in 20khz.
That frequency will pick up pieces for you at a depth that the 60khz simply cannot reach far enough to respond to in any way.
You may work out in the end, as I did when I held a compulsive addiction to very small gold many years ago, that detecting in 60khz from the start in an area, will have you bypassing signals that you would've picked up on by the lower frequency's.
In 60khz, you are really only detecting an inch or so for very very small gold, (and wait till you have that sound working way up in your hearing, you can actually hear the internals of the machine tickling around every grain of dirt, it's like another dimension)
The only exception of coarse is larger pieces a bit deeper that it will hit. But the slightly deeper ones than that will be missed by the 60khz.
But, in 60khz, you will pick up many very very small pieces that 20khz will not.
2.
As for settings in any frequency, top volume, top sensitivity, the same tracking speed I was using on that ground type if it still suits the immediate area, normal signal - never fine or boost, and never in Fixed Balance as both tracking speeds will not be thrown off if the coil swing speed on that immediate ground suits the tracking speed your in.
Fixed Balance cannot change for you on a foot long swing, so you will not pick up a soft signal, mainly dropouts of threshold signals, in Fixed Balance when that ground changes, and it will change.
You gotta trust that tracking.
3.
What all call a Patch, but I call a Run, is I don't think ever quite 'cleaned out'.
But if the Eureka is only used there to start with, before bringing in other units, the 15" the 11" and the new 6" Coiltek coming out in a couple of weeks, and in the frequency's that suit each coil.
But more importantly is the coverage. The 15" has a 4" sweet spot at depth, It's located at the centre of the coil. So if you move each swing more forward than 4" further each swing with that coil you'll leave deep or soft signals un-heard. The 11" has around a 2.5" sweet spot at depth, the 10"x5" has quite a slim 1", and the new Coiltek 6" will have nearly an inch. Any further swing forward than those measurements will miss signals.
Then you have to detect by swinging N/S as well E/W with all those combinations. You just won't be able to stop yourself from doing that.
4.
Yep both those Minelab 11" and Coiltek WOT, best coil ever made, more sensitive than the 11" somehow, and much much deeper. It's the ideal size for depth too on a low frequency Vlf. That's the cut off point for coil size as any bigger and no more depth is obtained by making a larger one.
5.
I have a thing about talking about finds or selling local au.
I'd probably start a war if I told you the depth difference between one of these in particular that I've set up, in comparison to my gpx and sd's. But only with a detectable surface of fingernail size and up.
But I can tell you after years of changing coils and frequency's over targets, that I only detect with the 15" in 6.4khz, sometimes in 20khz but not often. And that this combination is the best to use.
I only use the Eureka on very hot ground.
The new 6" coil just may give me back an addiction to tiny gold, who knows.
The Eureka isn't the only unit I use, but It's one of the only 3 gold Vlf's I would ever bother to take out, it and the 305 and 705. But it is the best Vlf for gold detecting that's currently on the market today.
Made for hot ground, but mis-used by many.
