This rf probe is coupled with a fiber-optiCJ:able to the test equipment. It utilizes inexpensive components to improve probe performance at UHF frequencies. The receiving antenna in this probe feeds an envelope-detector diode. After amplification by the LF356 op amp, the low-frequency output modulates the LED, which in tum feeds the optical fiber.
The design facilitates the use of a single battery for the op amp, with voltage splitting by means of the 1-K!l potentiometer, and miniature 47-I"F tantalum capacitors to provide decoupling. The gain control is easily adjusted to give the best dynamic range for a specific LED.