  The operation of resistively-coupled single-electron transistor (R-SET) is
studied quantitatively. Due to the Nyquist noise of the coupling resistance,
degradation of the R-SET performance is considerable at temperatures $T$ as
small as $10^{-3} e^2/C$ (where $C$ is the junction capacitance) while the
voltage gain becomes impossible at $T\agt 10^{-2}e^2/C$.
