Doc introduced the Gold Cyclone back around Feb/March of last year as a forum topic on his prospecting forum of which I am a member. There are numerous questions and promises to purchase but no user reports that I recall. This may be because the users/buyers are not members but I suspect probably because of poor sales.
I love the science based principles in the design and I am convinced it works as advertised. One downside is that the material still has to be screened after each step. If I had or was producing more than than a hobbyist amount of cons I would seriously consider getting one. It would be interesting to see how well it would work with beach cons. Doc says he has tested down to about 150 mesh but that is probably the upper level of average gold size on your beaches. In the demo, Doc says the smaller the gold the larger the amount of Hyd. Eqv. black sand, etc. there will be but if there is a significant reduction of them it would certainly ease the final recovery effort especially if, at that tiny size, it makes the cons easier to pan as it does the larger sizes. I would like to see testing results based exclusively on minus 100 mesh beach black sand concentrates.
I can see where it is feasible to build one and it may work ok. I think the water supply is necked down by a nozzle or some type of reducer to create a venturi effect and speed the water for the vortex action. The 200 mesh screen seems to be, mostly, to support the material at or just below where the vortex water is introduced as well as to prevent some migration of material through it. Or it may be part of the nozzle. If some does pass the screen it should pass back through during cleanout.
