Want to upgrade coil but have a quick question

[erdin]

I have a quick question! I have already ordered a better Metal detector, which leaves me with my cheap Maplin metal detector just sitting there. So what I would like to do whales I’m waiting for my new one, is to attempt to put a larger coil on it.
Providing I keep the inductance and resistance the same would I need to do anything else to the MD.
Sorry if it sounds silly I’m new to electronics and just want to experiment.


Thanks in advance.

[Sean_Goddard]

Which model do you have as Whites coils will fit SOME of the ones Maplin sold.

[erdin]

Its the cheap L45BH.

It appears to have a 6'' concentric coil.

It kept giveing me false readings so i opened the coil housing up today and found the coil was loosely winded, so I winded some PTFE plumbers tape round it. This cure the false reading.

So moving back to the topic. If i make a larger coil of around 8 or 10'' and keep the inductance and resistance the same as the original coil will i need to do any thing else.

or is there an other way of modifying the metal detector to give more depth?

[metal mania]

what were your readings by the way i was wondering the same thing any updates

[WM6]

For bigger coil you can keep the same inductance and approximatelly the same resistance of TX and RX windings.

But very likely you will (can) not keep the same inductive coupling between TX and RX windings, so bucking coil cannot be of the same L and R. Without proper bucking coil there will be hard to nulling coil (if we are speaking of CC coil as original one).

Try with DD coil, you do not need critical bucking coil there.

[metal mania]

O k thanks so move away from cc and use dd makes sense thanks