Standard RC receivers accept only 1000-2000uS PPM signals and your servo travels 90 degrees with this signal. 

This small circuit is expanding your servo travel 2 times for 180-degree for the pan-tilt applications, head trackers or camera mounts.

Features

• 30cm Servo cable with male and female connectors
• expanding the servo signal from 1-2mS to 0.5-2.5mS 

Important: 

• Servo resolution reduces 2 times when expanding and this may affect some servos as visible steps on the movement. 
• We are expanding the PPM signal only, your servo must support 180-degree travel for a full range of expander. We are suggesting analogue servos for usage. Because digital ones limiting the input signal between 90-120 degree range.