True value in non-metallic lower rod?

[IDXKevin]

Hello all-this question may be for Carl as I absolutely trust in what you have done with Whites. I absolutely love my IDX Pros and want to squeeze every bit out of them. I understand they're a motion based detector and as long as there is no flex in the lower rod there won't be any falsing. But has it been proven that the aluminum lower rod takes away any,no matter how miniscule,performance from the machine because it has to compensate for the aluminum it sees during ground balancing? I ask because I see Whites offering the non-metallic lower rod recently. I have seen some discussion on this subject but would like an opinion from someone who knows for sure! (doesn't really matter who as long as it's definitive). Thanks so much for this great learning site!

Kevin D.

[Carl-NC]

An aluminum rod has no effect on target ID or ground balancing, assuming there is no motion of the rod relative to the coil. But it can affect the dynamic range of the coil by creating a large static signal, and if you're in heavily mineralized soil it can make overloading worse. Also, with the increases in sensitivity, I suspect modern detectors would pick up the slight movement of the rod from coil flexing.

[Qiaozhi]

On a similar line, the use of metal stem bolts is not recommended either.
As a practical example, the Laser Hawkeye has a metal stem bolt fitted as standard (as do other Tesoro detectors) and replacing this with a plastic bolt will greatly reduce unwanted chatter. Although the metal bolt does not affect ground balancing, it does distort the magnetic field of the coil and reduces sensitivity. It's like you're carrying around a metal target attached to the coil.

[IDXKevin]

Thanks guys! I live in southwestern WI where lead and zinc mining have had a storied history. Although I can easily stabilize my machines in any given site I hunt,it's good to know there is potential for the overall setup to be even better!