The role of them=0 modal components on the reversed‐field‐pinch (RFP) dynamo effect is examined in the single fluid magnetohydrodynamic (MHD) model by comparing results with and without various nonlinear convolutions of them=0 spectrum. Results indicate that the dynamo effect comes directly from them=1 instabilities and the effect of other nonlinear convolutions is small. Scaling studies of &dgr;B/Bwith the Lundquist number (S) are also performed. It is found that &dgr;B/Bis independent ofS(diffusionlike scaling), which is consistent with the view that the dynamo effect arises directly from them=1 modes.