Here you will find a review of Teknetics Omega 8500 metal detector. From the article you will find out about what differs this model from other metal detectors in the product line, what operating frequency the device uses, what kind of searchcoil it has, if headphones are included into the device package set, how long it works using one battery set and other important information.
What was the device designed for?
Teknetics Omega 8500 metal detector is a flagship model of the product line (Alpha 2000, Delta 4000, Gamma 6000 are also devices from this product line). This is a semi-professional ground search metal detector with a full set of functions: discrimination, 4 sound tones, pinpoint, VDI, manual ground balance, GROUND GRAB function, displaying soil mineralization level on the LCD, etc.
|Model||Teknetics Omega 8500|
|Weight||2.5 lbs (1.1 kg)|
|Length (Adjustable)||43” – 53”|
|Batteries||9-Volt Alkaline (not included)|
|Standard Searchcoil||10” (25 cm) Concentric|
|Operating Frequencies (kHz)||7.69 kHz|
|Water resistance||Waterproof coil|
|Discrimination||8 Categories + Notch|
|VDI (0 to 99 scale)||Yes|
- User-friendly metal detector ideal for coin shooting, relic hunting, and gold prospecting
- Large, easy-to-read LCD display with 2-digit numerical target ID system
- Running depth indicator identifies target depths from 0 to 8 inches
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Teknetics Omega 8500 was designed using 3 section shaft, but unlike the earlier models, the control unit of the metal detector is attached not to the upper shaft section, but it is mounted on a special handler covered with polyurethane.
On the upper shaft section you can find an armrest with a cuff, the latter is included into the standard device package set. The armrest can be shifted along the shaft to adjust it to the user’s individual parameters.
The upper and the middle shaft sections are made from light weighted aluminum alloy and covered with a powder paint. The bottom shaft section is made from solid plastic (carbon). Therefore, there is no need to worry that after long-term usage the shaft sections will lose their initial appearance.
The middle shaft section has eight adjustment holes, due to which the user can adjust the shaft length to his height. All the construction is assembled by means of spring buttons (which serve for preliminary fixation) and camlocks with swivel washers.
When assembled the metal detector has quite acceptable weight – just 2.3 pounds.
Teknetics Omega 8500 uses 7.8 kHz operation frequency. The metal detector includes 11 inch elliptical concentric coil in its standard package set.
The searchcoil is protected with a monolith plastic case, which protects the sensor from hitting obstacles and wearing as well as it makes the coil completely waterproof.
The searchcoil cable has a thick elastic braid, which doesn’t get hard at low temperatures. The cable is fixated around the shaft sections by means of two soft clamps made of touch and close fastener.
The jack plug has a threaded swivel nut, so there is no chance that it accidentally unplugs during the treasure hunting process.
We should mention, that this searchcoil doesn’t need some special additional protection, since its bottom is protected by means of the monolithic plastic case. It protects the sensor from wearing and also ensures that the coil is completely protected from water and moisture ingress.
Headphones are not included into the metal detector package set. On the back of the control unit there is a battery holder; on the left side of the control unit there are two input jacks to connect any kind of stereo headphones.
The metal detector uses one 9V battery as a power supply. At normal temperature conditions one alkaline battery is enough for 20 hours of continuous operation of the device. If you use headphones, the operation time will increase correspondingly. You can also use accumulator batteries, though the metal detector operation time will decrease in this case and it will be about 8-10 hours in a row.
The control unit
Teknetics Omega 8500 control unit is rigidly fixed to the handle, but the metal detector is rather small sized, so it can be carried and stored in a standard backpack.
Under the display you will find the following control elements: two potentiometers and seven touch sensitive buttons, which are hidden under the plastic panel and this way are protected from dirt and dust ingress.
The left potentiometer is used to turn the device on/off as well as to adjust the sensitivity level of the metal detector.
The right potentiometer also has two functions. If you turn it to the left (i.e. contraclockwise) till it goes click, the metal detector will switch to AUTO TUNE mode, which is a search mode with automatic target response adjustment.
Between the potentiometers there are buttons to control the metal detector. Buttons “+” and “-” as well as GND GRAB are responsible for ground balance function adjustment.
PINPOINT button switches the metal detector into a static mode of target center detection.
On the right you will see FREQ button (it is responsible for the operation frequency adjustment), TONES (by means of this button the user changes the number of tones in the response signal), and NOTCH button (it turns on the mode of selective discrimination).
The metal detector has two basic search modes – discrimination and All metal mode. Switching between them us performed by the potentiometer located on the right.
When the discrimination mode is on, you can select between two options of discrimination scale adjustment which is displayed as a semicircular diagram.
You can discriminate metals one by one or select those from eight discrimination segments, which you don’t need by means of NOTCH mode.
In case when you exclude discrimination segments sequentially, metal objects will be the first the device stops detecting, since this is the metal with the lowest conductivity. Then you can exclude foil from the detection range and so on.
However, there may be situations when you have to exclude some specific target type, for example, bullets. To do this, you should use NOTCH mode, and exclude the objects you don’t need and leave only objects low and high conductivity.
Professional diggers use All metal mode more often. The thing is that in this case you will receive signals from all metal objects, and though they don’t have different tone signals you can identify them using visual indication with the help of the digital indicator and the marker on targets scale that becomes highlighted.
All metal mode provides essential increase of the device detection depth, since the target signal don’t pass through all the filters and its is displayed directly on the LCD.
The main visual indicator is VDI number displayed as a two digits number in the middle of the LCD display. When the numbers are close to zero, we can say that there is an iron object in the ground and when VDI numbers are close to 90, we can suppose that the object is made of silver, for example, or copper.
At the each VDI number has a targets sector corresponding to it. Each of the sectors has a sign, which gives approximate characteristics to the group of objects that can include the object being studied.
Maximum number of response signal tones is four. At that low tone corresponds to targets made of iron and the highest tone is received from targets with high conductivity (silver or golden coins).
If you don’t need four tone response signals, you can decrease the number of tones and leave just two tones, for example. One of them you will hear in case of detection some iron target and the other – for objects made from non-ferrous metals and alloys.
The user can see between desirable and unwanted targets with the help of the constant background sound that the metal detector produces, which is called a threshold tone.
When you use it, you hear constant noise and studying the way it changes you can make conclusions if there some deep or small metal objects in the ground, which due to their physical properties and location can’t produce their own signal.
Detection depth of the metal detector depends on the properly adjusted ground balance function. Metal detectors with fixed ground balance value demonstrate average detection depth, Teknetics Omega 8500 is capable of significantly higher performance.
Ground balance in this device can be adjusted both automatically and manually.
Teknetics Omega 8500 has several systems to control the ground parameters. First of all, you can see how mineralized the soil is by looking at the scale in the top right corner of the display; i.e. you can evaluate the prospects of your search at this specific area before you start adjusting the metal detector settings.
Besides, to maintain constant level of ground balance, there are two scales – you can see them in the left side of the display. Ground balance value is displayed in the bottom right corner of the display, to make sure that the user can follow how the value changes within the selected search area.
In most cases it’s not a problem to adjust the ground balance properly, but when the soil is complex, stony or there is a lot of ferriferous oxides, saline minerals in it, the metal detector will have to do its best to ensure proper performance.
Teknetics Omega 8500 has one more function that can be useful for those who go treasure hunting next to objects producing electromagnetic waves, near power transmission lines, underground utility systems, etc. In this case, you can shift the operating frequency anytime to suppress the noise and continue working.
Shifting the operation frequency doesn’t affect the metal detector performance, but it ensures that you easily get rid of the electric noise. This function is very useful in case when there are several Teknetics metal detectors around working using the same operation frequency as well as during some digger competitions.
As for my personal impressions from using this metal detector: it is very quiet, it produces signals only in case if there is really something under the searchcoil, if there is no target around it is just silent and I even checked if the device is still on by moving the shovel under the coil.
The discrimination function performs rather accurately – what you see on the screen you will find under the coil. I didn’t dig any object made of ferrous metals (first, I waited till I get used to the device, however there were some targets of this kind, but very few of them).
The device produces very prompt target response: I don’t look at the display at all, since I use the tone signal (first I receive the tone signal and then some information appears on the display). The metal detector is good for finding small and very small objects (sometimes I spent half an hour on searching for some tiny copper plate or non-ferrous metal chips).
The metal detector is quite user-friendly in terms of settings.