This paper reports on preliminar frequency stability performances of a compact CPT-based Cs vapor cell atomic clock using the push-pull optical pumping technique (PPOP). This clock uses a single distributed feedback laser source externally modulated with a Mach-Zehnder intensity electro-optic modulation for optical sidebands generation. The clock short-term frequency stability is measured at a level of 3.0 × 10−13τ−1/2 up to 80 s averaging time, in good agreement with the signal-to-noise ratio limit. These short-term frequency stability results are encouraging and close to those of best vapor cell atomic clocks.