We demonstrate a high-stimulated-Brillouin-scattering-threshold monolithic pulsed fiber laser in a master oscillator power amplifier configuration that can operate over the C band. In the power amplifier stage, we used a newly developed single-mode, polarization maintaining, and highly Er/Yb codoped phosphate fiber with a core diameter of $25\mathrm{\mu m}$ . A single-frequency actively Q-switched fiber laser was used to generate pulses in the hundreds of nanoseconds at $1530\mathrm{nm}$ . We have achieved peak power of $1.2\mathrm{kW}$ for $105\mathrm{ns}$ pulses at a repetition rate of $8\mathrm{kHz}$ , corresponding to a pulse energy of $0.126\mathrm{mJ}$ , with transform-limited linewidth and diffraction-limited beam quality.