The phase behaviour of the binary systems ANBC(nC)-n-tetradecane, for nC = 8, 16 and 18, was examined using DSC, paying special attention to the role of the alkoxy chain of the ANBC molecule in the D phase. The dependence of the SmC-D and D-isotropic liquid transition temperatures upon the apparent average number of paraffinic carbon atoms closely resembles the nC dependence in the series of neat ANBCs, demonstrating that the alkoxy chain behaves, at least in part, like the solvent in lyotropic liquid crystals. The D phase was not detected in ANBC(8)-n-tetradecane.