A compact, solid‐state radio frequency oscillator of low‐power consumption is described which allows quantitative measurement of the optogalvanic effect in low‐pressure gas discharges. The oscillator has been used to record a portion of the 2‐0 overtone band of nitric oxide at a pressure of ∼1 Torr using a tunable color‐center laser operating at 2.65 &mgr;m.