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To make the most of your metal detector, it’s better to have multiple search coils to use them in a different location.
This is expensive. But the recovery rate will increase and you’ll be happy with the investment you’ve made.
There are many search coils on the market with different shapes and sizes. Each one of them is suitable for a certain environment.
The best search coil for trashy areas should small coil (less than 6 inches) and should be a double D.
Why are small DD ones the best?
Coils differ by their sizes and configurations (the way the transmitter and the receiver are placed next to each other).
The search coil size
The coil size has an impact on the volume of the magnetic field it can produce. The larger the coil the larger the field.
This means that the depth range of large coils is greater than smaller ones. Roughly, the depth a coil can reach is equal to its diameter.
- Search coils come in different sizes ranging from 5 to 11 inches and beyond.
Small coils (less than 6 inches) are the best for trashy areas. They are light and comfortable to use. The lighter the metal detector, the longer you can use it without getting tired.
They fit in tight spots like under the bushes. And they are sensitive for small targets.
But their depth range is limited. And they cover a small area every time you swing the metal detector.
- Large search coils (more than 11 inches) can detect deeper large objects (like caches). They cover a larger area per sweep.
Their greater depth range and coverage don’t mean necessarily that the recovery rate increases.
In the case of the Garrett AT Pro, many detectorists said that they found more coins using a small sniper coil than with the stock bigger coil.
Lager coils are less sensitive to small objects. Maybe this why using a small coil results in recovering more coins. And they are not suitable for trashy areas.
To conclude, small coils are better for trashy areas.
Any search coil is formed by two types of coils: a receiver and a transmitter.
The transmitter emits a magnetic field. And if you swing the detector and a metal object is nearby, a current will be induced in the object.
This current creates a magnetic field which is detected by the receiver coil. And you hear the Beeps.
The receiver and the transmitter can be placed in two ways.
- In the double D search coil, the transmitter and the receiver coils are side by side with some overlap. The shape of each one of them is a D.
It’s good for the trashy and mineralized ground. Its field has the shape of a book.
- For the concentric coil, the receiver and the transmitter are concentric. The latter is on the outside and the receiver is on the inside. Its detection field is a cone.
Pinpointing with this type of coils is easier. However, it’s not suitable for highly mineralized ground.
Tips to deal with trashy areas
If your metal detector has a target ID, it may shift a little bit after mounting the new smaller coil.
The target ID is a number displayed in the screen of the detector that helps you identify the buried metal object based on its conductivity.
That way, you will decide whether you dig a hole to recover the target or not. In most cases, this is a time saver.
Because you will dig a plug only if you expect to find a valuable item.
However, in trashy areas, you will find a lot of pull tabs. Many metal detectors will have hard times distinguishing between them and gold rings.
So, it’s up to you to decide whether or not to dig a plug any time you get the digital ID of a pull tab or a ring.
To get used to the shift in the target ID, grab some metal objects and pass them in front of the coil and note the new target ID.
Many detectors have a different tone for each conductivity range. So you may notice that the audio signal for certain metals shifted as well.
When you hunt in trashy areas, lower the sensitivity until there are no false signals.
Small coils are great for trashy parks. But Their depth range is slightly less than the larger ones.
You can stick it to the ground to go for an extra half an inch. And to avoid damaging it, use a coil cover.
If trashy parks are annoying you, pick the smallest double D coil you can get for your metal detector.
Don’t forget to relearn the meaning of the target ID and the audio signals.