Steve Have you ever heard of this problem and tell me if you think you know what it is... I have a Equinox 600 and I got vdi issues where I will be swinging the Detector hit a signal and then not want to dig that and keep swinging and it will show another vdi and then freezes up while I'm still swinging and then -- will show and then after six seconds or so 00 and then go again and same thing and I have turned sensitivity to 20, recovery speed 3 iron bias 2 and ground balance on auto tracking.... I also will swing over a vdi and it will jump and lower and jump and lower. And on pinpointer mode it sometimes won't have audio but I back out and try again it does. This is for sure a bug. Right?
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
Here is my problem. I bought this used and I know it's older then 3 years and it was working fine. I can hear the threshold but I can't hear the target response. In this case the target is a gram nugget. I have a metal fire pit in my backyard and I have to put the coil about 6 inches from before I hear a response. This problem comes and goes for what it's worth. I have tried different coils with the same results, used those same coils on my 3000 and everything is dandy. On the front panel I have the switches set as Fixed, Double D, Normal, and General. ( I was using Double D coils) I have tried the Factory preset and the problem is still there. Any ideas before I sent this off to Minelab?
By Steve Herschbach
There is a previous thread with a lot of speculation about just what is going on with a couple of the Nokta Impact all metal modes, the Gen(D) and Sta(D) modes. The thought was that they are mixed modes - in other words modes that are running both all metal and disc in parallel.
The speculation garnered attention and we have now been provided this explanation directly from Nokta Software Team Leader Alper Tozan regarding these 2 modes:
''I read a lot of comments about Gen (D) and STA (D) modes in some forums and firstly, I want to thank you about all your positive thoughts. On the other hand, I want to clarify one thing. In some forum discussions, these modes are defined as ‘’mix modes’’. These modes are not mix modes as mix modes typically result from at least two different software algorithms or hardware circuits working at the same time for decision making to discriminate and detect metals. These mix modes also show characteristics of two or more different modes at the same time including handicaps of each signal processing.
Gen (D) mode, on the other hand, is a true threshold based all metal mode with motion that can discriminate metal without needing any other hardware or higher order software process level. So it always behaves like a classical true threshold based all metal mode but with iron tone and tone break.''
Frankly, for me that raises almost as many questions as it answers. Is an all metal mode that discriminates an all metal mode? Is it not instead a different kind of ferrous/non-ferrous discrimination mode? Whatever it is, it is unique, and that's enough for me! So I will do what I normally do and ignore what is going on under the hood and pay attention to just what it is these modes actually achieve by way of useful results in the field. More on that at a later date.
From Nokta Impact Owners Manual, pages 12-13:
Static Mode (STA)
This is a non-motion mode. In other words, the device will generate an audio response when you hold the coil stationary without swinging over the target. The audio response increases in volume as the coil approaches the target. This mode is recommended for larger and deeper metals.
In the STA mode, the device will generate the same audio tone for all metals and it will display the target ID on screen. At the same time, the ID scale will fill up to the right in proportion to the signal strength.
Target ID range is 00-99. 00-40 are ferrous and 41-99 are non-ferrous metals. You can discriminate out all IDs below a certain ID by using the Disc. setting and simply avoid these metals in the field.
When the device detects a discriminated metal, it will not produce an audio response or an ID. However, the ID scale will fill up to the right in proportion to the signal strength.
The threshold in this mode is internal and cannot be adjusted by the user. Changes in the ground and temperature may lead to drifts in the threshold. Threshold drifts will be reflected in the ID scale either in the positive way (right side) or the negative way (left side). The device may emit an audible response in the positive drifts but not in the negative ones. When the threshold drifts, pull the trigger once to retune the detector. Retuning periodically while searching in this mode is recommended.
IMPORTANT! For a more stable operation, try keeping the coil consistently at the same height above the ground where you retuned the detector.
IMPORTANT! If you retune the detector over a target, the threshold will drift to the negative side and the device will no longer detect the target until the detector is retuned. In addition, the depth of the detector will also decrease.
If the drifts are substantial and retuning does not improve the situation, increase the iSAT setting in the Expert Settings to a level where the drifts are eliminated (for detailed information on iSAT please refer to page 24). As the iSAT is increased, the device may detect weaker signals but will not be able to detect the targets anymore if you hold the coil stationary or sweep back and forth over the target. If the drifts still continue frequently, drop the gain to 39, decrease the iSAT and re-ground balance.
Static Delta Mode (STA (D))
In principle, it works the same as the static mode. The difference is that the static delta mode will generate the same tone for ferrous and non-ferrous targets at fringe depths but it will discriminate the shallow ferrous targets by emitting a low iron tone. Also, Disc. setting is not available in this mode.
Please refer to Table 2 at the end of the manual for different settings used in STA and STA (D) modes.
General Search (GEN)
Different than the other modes, this mode features a threshold tone which is continuously heard in the background.
General Search (GEN) mode is used in 2 different ways in the IMPACT: 1) with the Disc. setting disabled at 0 2) with Disc. enabled (non-zero). When the device is first turned on, Disc. setting will be off. When the Disc. is set at 0, the device does not discriminate targets and detects all targets (metals, mineralized rocks etc.). ID of the detected target is shown on the display (except for negative hot rocks) and the same audio tone is provided for all targets. The audio tone increases in pitch as the coil approaches the target. This is the typical All Metal mode found in most detectors.
When using the Disc. Setting in this mode, the device will emit a low ferrous tone for all targets below the Disc. Setting, and a higher tone for all targets above the Disc. setting which changes in pitch as the coil approaches the target. Let's say you set the Disc. to 20. The device will generate a low iron tone for all metals with 0-20 ID and a higher tone for all targets with 21-99 ID. Upon target detection, the threshold will momentarily go silent and only the target audio response will be heard. The duration of the threshold's silence is directly related to the level of the iSAT.
Gain, threshold and iSAT settings in this mode are optimized to provide the best performance on different terrains. You can modify these settings based on ground conditions.
We recommend using the GEN mode when discrimination is not important and not using it in heavy trash areas or areas containing many hot rocks.
Audio Boost in the General Search Mode
This feature is not included in the settings on screen. Boosts the sound of weak signals received from small or deep targets making it easier for you to detect those uncertain targets. It is recommended that audio boost should be used on a temporary or as-needed basis because it will not only boost the target signal audio but it will also boost the volume of ground noise and false signals along with the threshold hum.
Audio Boost consists of 5 levels (b1-b5). At start up, the Audio Boost level is set to low (b1). To increase the Audio Boost level, pull the trigger and press the minus (-) button simultaneously. Audio Boost will only work in the GEN mode.
General Search Delta (GEN (D))
In principle, it works the same as GEN mode. The difference is that the Gen (D) mode will generate the same tone for ferrous and non-ferrous targets at fringe depths but it will discriminate the shallow ferrous targets by emitting a low iron tone.
By Nokta Detectors
Below is the link to the manual as promised.
I am sorry it took so long but we went thru several edits.
Thank you all who helped us with the manual.