Good mood to you, dear readers of our blog. Today I want to talk to you about one of my favorite topics. This is a discussion about using large coils on a metal detector.
How did it all start?
Like most novice diggers, in the second month of my passion for digging, I began to think more and more often. “Why don’t I have as many finds as those bloggers on YouTube???” And, naturally, the first and “logical” answer that came to mind was “It’s all the metal detector’s fault.” And then, the mood deteriorated, and I began to look at the metal detector with a sidelong glance. “Eh… you didn’t live up to my hopes. And I bought you for that kind of money.”
Familiar feeling? Is not it? I had no desire to sell this device and buy another one, so I decided to go the more logical route for me and buy a larger coil. I ordered, paid, and on the weekend closest to the purchase, a comrade brought me the reel. We’ll leave the topic of how my hand fell off after a couple of hours of digging for another story, but the very essence, whether the 13-inch coil helped increase the depth gain – we’ll discuss that now.
Comparisons.
Undoubtedly and unequivocally, the total number of finds as a result of the day's digging has increased sharply. Coping began to bring pleasure and self-satisfaction. Moreover, in the fall, most of the fields in the vicinity of our village were plowed. So there was plenty of room for a cop.
I did not conduct separate testing of the trouser coil of my Fisher F-70 and the purchased NEL Tornado on a buried coin. Everything was more prosaic. He came to the field, put a large reel and went to dig, after a couple of hours he changed the reel to a small one and went to dig again for a couple of hours. The result in the total number of finds, including garbage, is a difference of two or three times in favor of NEL Tornado.
When did the doubts start?
I met an interesting fellow countryman. We talked about life, about politics, about history, and so, one day he told me that he had a Fisher F-75 SE Black lying idle in his garage for 6 years. And this, at that time, was my pipe dream. And if you have a dream, then you need to go towards it. In general, we agreed and my friend gave me this device to test until he (the device) needed it himself. I received Black in January and before the opening of the season, two months, I walked around and licked my lips in anticipation of how I would start collecting kilograms of coins in old places with this professional device.
However, reality turned out to be more real than those dreamy plans. On the very first day of digging, I suddenly discovered that with a large coil, the sensitivity of the device had to be lowered. If on a standard DD coil the device worked correctly at 99% sensitivity. Then, when placing a large coil on the 82% sensitivity, the device began to hum treacherously and react nervously to any phantom signals. And, yes, when changing the coil, as advised on the Internet, each time I rolled back the MD to the factory settings. But this did not help, the device continued to buzz when the sensitivity increased above 82%
What's the matter?
The Internet helps me, specialized forums, and there, it turns out, this topic has been discussed for a long time, so you don’t even need to write questions yourself. It turned out that the size of the coils to increase the detection depth was taken into account in the era of analog metal detectors. In modern metal detectors, an increase in detection depth is achieved through the operation of unique software.
Undoubtedly, all sorts of range tests by bloggers give indicators of an increase in depth when using larger reels. But these same gains are not as large as we would like.
Inputs.
If the increase in the depth of a large coil, when compared with working on a standard coil, is not that great, then why during my tests on a real field, the number of finds was two and three times greater? And here everything is simple. It's all about the size of the coil itself. A 13-inch coil scans twice as much surface in the same time. That is, the efficiency for the same time on a mine is twice as high.
If the fields are plowed deeply, then the surest tactic in a good place would be to quickly comb out the top and large signals before the field is sown. And in this case, the use of a large coil gives a sure increase in the total number of finds. If you are going to dig in an abandoned tract on old grass. Then a standard DD will give the same results as a large 13-inch coil. In such locations it is best to work with a slow wiring speed, and a heavy reel does not allow this.
In general, if you have an entry-level or semi-professional level device, then a large coil will undoubtedly increase the detection depth only due to the fact that such coils are equipped with an additional signal amplification board. In budget metal detectors, manufacturers sacrifice such a board in order to reduce the price. That's why they are budget MDs. Whereas, I don’t see the point in buying and installing large coils on expensive and professional models of metal detectors.
If you, dear readers, do not agree with me or, on the contrary, agree, write your opinions in the comments and we will discuss everything. And, of course, thank you very much for liking the note if it was useful to you.
