First of all, for those who didn’t own at least a television set or radio, please raise your hands up! Oh, it seems that everyone is living in the modern days (Thank goodness, no one here is living in prehistoric era).
Ok, if you’ve setup the HF antenna in the past few years ago, and you’re not getting satisfied with it, maybe it’s about time to build your own Servo Control Circuit.
For this project, you’re going to use some small gearmotors, as they’re for drive the inductor switch. In addition, two air variable capacitors are needed to be putted on an MFJ 1500W antenna tuner!
Well, the fun part about this project is you have to use Lego gears (Please refer to the above picture) to drive the tuner. If you’re in doubt, whether the Lego gears are durable or not, then you should stop questioning about it, as Lego gears have been approved and certified as a quality product, which is able to withstand to any toughest conditions of all!
By the way, you might choose to skip the regulators and replace it with center-tapped transformer and a rectifier, if you found that the circuit is insensitive to power supply variations!