Upgrading Detector Shaft?

Hi, Can someone tell me whether you need to upgrade the shaft on a detector if you are using an 18 coil? Thanks

You don't really need to but some people that use large coils (of 18" or larger) do replace the standard Minelab upper shaft with an aftermarket composite shaft.

Hi Lindy, I run a 20" NF Advantage, or a 21 x 17 Detech SEF, and soon a 25" NF DDX. I've left my upper shaft as is, but I bought a longer after market lower shaft. I have read though that some people say you don't need to replace either of them. Maybe if I were using an NF 25" Mono Advantage instead things may be different, but I wear my pick behind my back and I don't have any problems with false signals or anything from either the pick, my keys or my phone in my back pockets so far.

Is there a reason for using a composite upper shaft mbasko? Is it just to reduce some weight?

Thanks for the reply guys - very helpful. will try with original shaft and see how we go. cheers all.

Deepseeker there is thought that the standard upper shaft can desensitise larger coils.
I think the main benefit is a little bit less weight.
My own opinion is that the upper shaft should be moving with the coil so in normal circumstances shouldn't affect the coil. If it did then so to would the coil cable, control box, arm cuff etc.

Sorry for late reply mbasko, only just checked back on this topic. Yes good point, and it does make a lot of sense what you say. There's a whole lot more metallic material it would pick up more than the upper shaft one would think.