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Many designs of metal detector coils use different gauges of wire for the TX and RX coils - why is that? Does the wire thickness influence other parameters rather then just the resistance and current carrying capability?

ron vais
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    Ron, you've already asked this here: https://electronics.stackexchange.com/questions/637319/search-coils-in-metal-finders/637350#637350 – Andy aka Aug 12 '23 at 17:21
  • ron vais - As commented above, this question duplicates part of a previous question which seems to be from you too - that's a puzzling situation. || If you need help using the site, either ask in chat or flag one of your own existing posts, select "in need of moderator intervention" and explain what help you need. Thanks. – SamGibson Aug 12 '23 at 20:32

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The diameter of the wire will slightly affect the inductance and inter-winding capacitance of a coil. However, for a "wide" coil, like those found in metal detectors, these effects will be so small that they can be neglected.

The current in a metal detector coil will generally not large enough to cause significant heating.

So, we are left with two factors, the resistance of the coil, and the price of the wire. The receiving coil will have lower current, and therefore resistance will be of less concern. So, a cheaper wire is probably used in the receiving coil.

Math Keeps Me Busy
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  • Thankyou for the quick answer - is it possible that the added resistence is designed to create some specific dumpening effect? – ron vais Aug 12 '23 at 17:16
  • @ronvais higher coil resistance will lead to lower "Q factor", meaning higher damping ratio. Lower Q factor will lead to a wider pass band. It is possible that the a smaller wire was chosen to lower the Q, but I think economics and ergonomics probably played a larger role in the decision making. – Math Keeps Me Busy Aug 12 '23 at 17:23