I'm getting only about 5-6" inches ,depth with on sensitivity setting of 15. And when my wife or I run a hand down the coil the machine detects it and sounds off. Also,,can't say I'm a big fan of the teardrop coil can't came with it,is there a coil of close to the same size that would perform better??
By Mike Hillis
Been thinking about my 8500
Now the 8500 has it warts, but it has some good things about it too. One of the 8500 warts is that it really works better with concentric coils. I don't know if it was designed that way or not but that is just the way it is, so I don't put DD coils on it any more. My frustration level with the 8500 is way higher when running DD coils. So I quit using them on the 8500. My preferred concentric coil on the 8500 is the 8" round Tek coil. It gives the best stability and target id accuracy, including on nickels.
Another wart of the 8500 is the 8500 operating manual, in particularly regarding sensitivity settings. The Omega 8000 manual tells you what is going on with the sensitivity control settings. The 8500 manual doesn't and so you get in trouble right away. On the 8500, just like on the 8000, Sensitivity settings of 1 to 70 are GAIN settings. 1 is lowest Gain, 70 is highest Gain. In other words, a Sensitivity setting of 70 is MAX GAIN. If site conditions (EMI, trash, ground minerals) allow, you can raise the Sensitivity settings above MAX GAIN into the HYPER THRESHOLD settings of 71 to 99. Since the operating manual doesn't spell this out, the tendency is to try and run up into the HYPER THRESHOLD settings thinking you are only running 75% to 80% power when in reality your are running 100% plus, and in most cases, site conditions don't allow for it, resulting in some major frustration.
I find that sensitivity settings around 55 to 65 work best for most sites in Deep 1,2, and 3. Deep 0 setting often allows the most use of HYPER THRESHOLD settings but Deep 1, 2, and 3 work best if you keep below Max Gain (70).
A sensitivity setting of 55 in d5 (non modulated audio tones) with the 8" round concentric is good for a hard hitting 8" dime, which is pretty decent, and leaves room for power increases if the site allows.
Some of the pluses I like about the 8500 is the full control of the segment audio. Instead of the normal disc or notch discrimination, I can just manage each segments audio volume. This gives me disc/notch capability while still seeing full display responses. When I combine this with the Primary and Secondary TID feature it allows me to focus on what I'm hunting for, which for me is nice gold jewelry.
I've already found some nice gold with the 8500 but now I think I'm going to specialize the 8500 as a large gold ring finder. Just going to cut the audio to all the segments except the Tab and Screw Caps segments, put it in VCO and hunt matching Primary and Secondary TID signals in places where men are most likely to loose a ring. Should be a successful strategy for larger gold.
Gonna find out. I'll let you know how it goes.
(might be a few weeks before I report back, forgot this weekend is going to be rainy and honey-do's are already lined out for me.
Teknetics Omega 8500 Data & Reviews
By Steve Herschbach
ATX, TDI, GPX. What is it with detector companies and three letter acronyms? I liked it more when they were called Coinmaster or Goldmaster. At least that gave you a clue about what the detector was supposed to do.
The three detectors representing the state of the art in ground balancing pulse induction (GBPI) metal detectors. The Garrett ATX, White's TDI, and Minelab GPX 5000. You rarely see them all pictured together so I thought I would post one.
Garrett ATX, White's TDI, Minelab GPX 5000
These three detectors are all very good at what they are basically made for, which is dealing with ground mineralization and hot rocks that make using VLF detectors very difficult. In particular VLF performance is severely impeded in extremely mineralized ground. In low mineral ground a good VLF prospecting detector running in all metal mode can deliver results rivaling PI detectors with the added benefit of having good discrimination options. Anybody doing much prospecting, however, will eventually run into locations where ground mineralization and hot rocks makes using a VLF such a challenge that a good ground balancing pulse induction detector is the only real option.
The GPX 5000 represents the current state of the art, and is the easy option if money is no object. It is well designed for long hours of prospecting, has an incredible variety of optional coils, and can handle most any ground conditions with many tuning options.
The Garrett ATX provides performance that comes close to the GPX at a much lower price, with the added benefit of being waterproof to ten feet. Actually, this is only a benefit if you need it. Otherwise it makes the detector heavier than need be and limits the available coil options. Still, if the GPX is not an option the ATX would be my next choice in a new detector with a warranty. For those needed waterproof it is the only real option along with its predecessor, the Garrett Infinium.
The White's TDI is an older design but still very capable. It costs less than the other two options, and unlike the Garrett it has light weight versions and models that can be hip or chest mounted. It is a good option to explore for those on a budget or needing the most ergonomic solution. The TDI is also a very respected beach detector, like the ATX above, but it has no waterproof option.
I'm a bit puzzled on timings, I've pretty much left mine in sensitive extra since getting it and it seems the go-to timing for around here. I only use mono coils and I'm basically chasing tiny gold in soils with very low mineralisation, 1 gram is huge for me so we are talking 0.0X to 0.3 gram bits on average that I am chasing. I was looking at timings charts on this site here and found the two best options for me below, I think. Sharp appears to be best if using a DD, does that mean I'd be best off sticking with my sensitive extra seeing I use a mono coil or is a DD coil worth considering?
I'm trying to see if there is a way I can scratch out a bit more depth on these little nuggets.
This chart is the one that throws me out the most, basically no timings are "Excellent" for mono coils except Fine Gold, Enhance and Sens Smooth which are more for mineralised soils, only DD coils seem to have Excellent for the timings I'm trying to use for the small gold in mild soils..... ?
And this chart below describes the two timings I think might be best for me.