One of the most frequently asked question by metal detectors’ users is what is the best way to wrap the coil’s cable around the stem?
Every user has his own preference. In this article, I will try to get some answers.
Why wrapping from the first place?
Before answering the main question of this article about the best way to wrap the coil’s cable, we should wonder why should we wind the cord around the shaft from the first place?
So, I sent an email to the Fisher labs and to Garrett metal detectors.
I read the user’s manual. You recommend wrapping the coil’s cable around the shaft.
What is the reason behind this? Why can’t we just straighten the cable from the coil up to the control housing? Does the wrapping direction of the cable matter (clockwise or not)?
This what I got from Fisher labs
The coil cable is 7’ long and if not wrapped around the stem it will be hanging loose, which can cause false signals. It does not matter which way it is wrapped around the stem.
And this is what I received from Garrett
Wrapping the cable, with the first loop close to the coil going over the top of the shaft is the recommended set up for all Garrett detectors. While running the cable straight up would work decently near the coil, it would leave you with slack in the cord near the control box which would flop around and potentially catch on branches, etc. when you are detecting. Wrapping the coil cord with the first loop going below the shaft near the coil put the wire in that cable very close to the top of the coil and potentially within the detection field which could cause false signals.
US Hobby Customer Service
Wrapping the cable around the shaft or straightening it from the coil to the control box does not really matter.
So why do we have to wrap the cable around the rod?
Simply because it is longer than the shaft. And, the only way to keep it from dangling and causing false signals is to wrap it around it.
The cord is longer than the stem. Because the length of the latter is adjustable. And, you only get one cable which should be long enough to connect the coil and the control box.
For Fisher labs, the winding direction does not matter. But for Garrett, you should do it clockwise to avoid possible interference.
This is not directly related to direction. If you wrap the cable anticlockwise, the first loop will be too close to the coil and you may get false signals.
What is the best way to wrap the cable?
Start by installing the coil and adjusting the length of the shaft. Then wind the cable around the stem.
The cable must be wrapped tightly to prevent it from hitting the rod and causing false readings.
Leave enough slack at the bottom of the stem so that you can adjust the angle of the search coil. You may need to do that if you are metal detecting on uneven ground.
You don’t need to use duct tape, Velcro plastic, zip ties, electrical tape or anything to hold the cable. Just don’t let it flap around.
But if you want, you can use Velcro to hold the cable snuggly. Avoid using duct tape, because it will be more difficult to replace the coil.
Keep the direction clockwise. This is recommended by Garrett even if your detector is from another brand unless the user’s manual says otherwise.
Don’t wind the cable too tight so that you could change the coil easily if you wanted to.
This video has helpful information that you may like.
Some common misconceptions
Some people think that it is better to run the cable straight up few inches from the coil. Then start warping it until you reach the control housing.
They think (this not the only reason) that this helps them to avoid false signals caused by the electromagnetic field coming from the cable.
Because if you wrap it around the stem, you make a coil. There is an electric current in the cable, which creates an electromagnetic field.
The latter may interfere with the field of the search coil. Thus, causing false signals.
However, this is not true. The cable is balanced which means it will produce magnetic fields that will cancel out.
Second, the coil has a lot more turns. This means that its magnetic field is much stronger than the cable’s field (if it exists).
So, wrapping or running the cable straight along the lower stem doesn’t have any effect and cannot cause false signals.
But you still can wrap it that way if you want.
What to do if you get false signals?
Check if the coil’s cable is wrapped snugly. Wind or bushes can move it around and thus you may get false signals.
Lower the sensitivity. In order to detect, smaller and deeper metal object, you have to increase the sensitivity.
But, at a certain point, you will hear a lot of noise (false signals). This is when you should lower the sensitivity a little bit until the chatters fade away.
If you have an entry or a mid-level metal detector, it will take care of ground balancing automatically.
This type of detectors can handle many types of soil. But it can’t run with salt beach sand, ground full of mineral or dirt full of iron dioxide (rust).
So stay away from places with this type of soil to avoid false signals.
Metal detectors for more advanced users let you adjust ground balance manually. So if you hear a lot of noise, just adjust it.
The coil’s cable may be damaged from the inside (defective electrical connections). This video will show you how to fix it.
If you cannot fix it, just buy a new one. I do not know whether you can find the spare parts easily or not.
I hope you found this article helpful. Please, leave your question in the comment section down below. So what is your favorite winding method?