For FB group Building Transistor Radios
Bob Johansen
After building several of the regenerative receivers, I think I figured out the reason why regens are so difficult. The circuit has to do so much with very few parts. If one part value is changed to improve one thing, it adversely affects something else. The tickler coil has to make the Q of the circuit much higher, in order to get good selectivity. At the same time it has to amplify without oscillating. But then when it’s on the verge of oscillating, it’s unstable, so it has to be manually adjusted to keep from breaking into oscillating. All of this instability is what we who design and build our own circuits try to avoid by good design, and it goes against common sense things I’ve been doing for decades. I had one that worked so much better when I connected the ‘scope probe to it. That probe cannot be included in the final design!
I’ve been experimenting with superhet receivers and despite being more complex, they are so much better in so many ways. Regens are not for those who want to have a receiver that works with consistency and stability.