Makro CF77 - What coil for Gold?

Hi Guys -

I have a CF77 which I have had for quite some time now. I am wanting to make up a straight shaft for it and try to locate a small aftermarket coil to use for prospecting - Has anyone used the CF77 for gold hunting? - What would you recommend to use? - I am kinda wanting a small coil so I can hunt around rocks & bush -

Cheers & thanks -

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