I'm using the stock AM 27Mhz radio from Traxxas. It doesn't have a failsafe built in.

And, I already have a Duratrax failsafe on my truck, but I wanted to research a little more to understand how it works.

I mean, I'm not planning to replace a $20 failsafe that works great! But, it would be nice to know how to make one and "see"' the inside magic.