Simple Reed Servo Driver, by Bobby Hill
June 1968 American Aircraft Modeler

June 1968 American Aircraft Modeler

June 1968 American Aircraft Modeler magazine cover Table of Contents

These pages from vintage modeling magazines like American Aircraft Modeler, American Modeler, Air Trails, Flying Aces, Flying Models, Model Airplane News, & Young Men captured the era. All copyrights hereby acknowledged.

At the request of a website visitor Bobby Hill, I hunted down and scanned this Simple Reed Servo Drive circuit of his that was published on page 31 of the June 1968 American Aircraft Modeler magazine. It was part of a monthly column by Howard Mc Entee called Radio Control World.

Simple Reed Servo Driver

Simple reed servo driver: As was the case with his trim servo amplifier for converting reed servos, which we diagrammed in a past issue, the self-neutralizing amplifier shown here will fit inside a Crescent 15-pin plug, so doesn't even have to go inside the servo. Arrangement has been used by Bobby Hill (2125 18th St. S. E., Washington, D. C. 20020) with Duramite servos. Circuitry should be such that negative voltage is applied to the bases of the 2N1303 transistors, when a reed vibrates. The four positioning contact strips are all connected together as a safety factor, and to lower resistance.

Simple Reed Servo Driver - Airplanes and Rockets


Bobby Hill, a dedicated reed flyer, developed this remarkably simple reed servo drive amplifier that requires no bias battery. We needed this idea ten years ago! Other applications possible.