JFET and MESFET structures, and processes of making same, for low voltage, high current and high frequency applications. An object is to provide high syngas conversion rate, minimum content of waxes in the products, high content of C10-C20 fractions per pass within a single reactor and avoidance of use of expensive catalyst components. Row decoding is performed in two levels. In a preferred embodiment, an air conditioning unit is mounted in the camper top. Another layer is at least partially formed from the first medium, such that the first and second layers share a common medium.