Since I got my Ithakas, I tried dual coils from time to time, just to confirm dual coils are not for me, I mean, I have the feeling that dual coils take more time to heat, of course, all depends on the final resistance and wire gauges used and in my personal opinion (and according to my experiments) is that dual coils are very aggressive for the batteries and the result is not much better than a good single coil configuration (I have tried duals in = and X mode).
Thinner gauges react faster but less turns around the wick (I have experimented with dual coils using nichrome 36 AWG, 34 AWG, 0.17 mm and Kanthal 32 AWG, always trying to achieve a final resistance of 0.8 - 0.9 ohms).
About flat or ribbon Kanthal:
I was playing with different sizes (gauges) of ribbon Kanthal last night, I have 0.3, 0.4 and 0.5 mm
I started with the 0.3 mm one, it gives little more heating surface than the 32 AWG round Kanthal wire, but as I use it around two wicks, it only takes a couple of turns around the wicks to achieve a final resitance of 1.3 to 1.5 ohms.
With the 0.5 mm one, you can achieve lower resistances with more turns and more heating surface, but at the same time there is more metal material, and I can notice it tooks more time to heat, so to get good results with this wire I have to make configurations with 1.1 - 1.0 ohms. In this case, I think there is not much benefit of having "many" turns of flat wire around the wicks, because air mostly hits at the center part of the wick.
Too low resistances = hotter vapor, but sometimes the mouthpiece gets very hot, also some liquids do not taste good at very low resistances.
The 0.4 mm one (the one that I'm currently using) is a balance between the above two, in configutations of 1.3 - 1.4 ohms.
Other important factors are the wicks, what diameter is it, quality of the wick, how tight are the coils around wicks, how fast with which the wick can supply liquid (you have liquid control, but there are cases in which the wick does not supply liquid fast enough, you open the liquid control to compensate it and it starts to gurgle), liquid density, etc. etc.
Yesterday I started to experiment, because I was using a RBA inside my UFS, the thing is that the resistance was 1.8 ohms, and I was having better results / performance (better flavor, better vapor production and vapor concentration) than with my Ithaka configured with a single 0.5 mm, 1.0 ohms ribbon Kanthal coil.
Then I started to remember about my iAttys, if you read some threads you will notice that a lot of GG old users said iAtty is the King, and it is its preferred GG atomizer, because the flavor, the vapor production and vapor concentration. Then, thinking about it, I remembered that at that time using a 1.5 ohms resitance in the iAtty was the thing (at least for me), I use to configure my iAtty with resistances of 2.0, 2.1 ohms, and I remembered what Imeo said long time ago, I do not remember textually, but it was related to the thing I wrote above, thinner wires react faster, due there is less material to heat.
Going back to the basics I configured one of my Ithakas with a single coil 1.5 ohms, 0.17 mm nichrome wire configuraton, the coil was around a single wick, in X configuration, with a wick without wire on top, it worked very good, the only thing is that the vapor was not warm.
Now, what have those two atomizers (RBA in UFS and iAtty) in common? The ceramic cup. It is so small than coils are very close each other, as the size for the coils is small, you have to use thin gauge wire (that reacts faster), also, due the small space, air hits practically all the coils, producing more concentrated vapor.
I was wondering how a Ithaka will perform with a smaller ceramic cup, with all its features.
I'm not saying nor implying Ithakas are not good, on the contrary they are very very good, with all the features, innovations, endless possibilities they provide, are simply the best atomizers, but you have to find your sweet spot. That is one of the nicest things of GG atomizers, they provide a endless set of possibilities, each one with its unique characteristics.
Of course, there are many many configurations I have to try, as microcoils and so on, I'll keep experimenting, I just wanted to share my experiences.
