hexohm v2

Yeah sure the 2.1 might be last years news, but for those out there that still love your 2.1 or maybe you bought a used one, I spent a night working out a small chart that fits rather nicely inside the battery compartment, that breaks down the voltage at each percentage of the potentiometer and...

i was thinking about buying a hexohm v 2.1, but i havent started using RDA´s yet. So i was woundering is it possible to use a sub ohm tank on the hexohm or would it be better if i started building my own coils before buying it? and what rda would you recomend me buying?