A little over a year ago, I had a project that required driving an RF single-pole double-throw (SPDT) coaxial switch either by transistor-transistor-logic (TTL) pulses sent by an external source or by ...
Fig. 1: The modified control board, with the two ultra-bright LEDs. Harry Bingaman is former director of engineering for Sudbury Broadcasting in Pennsylvania. Harry retired last fall from the group ...