FET Regenerative Receiver

This week I built a regenerative receiver. The schematic is based on W1FB QRP notebook and the construction ugly style, with all the components soldered in a PCB ground plane board. This was another exercise of going back to the basics, but, as always with the simple things, it was lots of fun.

The tuning is range is from 4 to 11Mhz. It was possible to ear some short wave stations. The frequency range was measured by inserting the frequency counter in the antenna input! Weird? No! When the FET is oscillating some energy is radiated by the antenna. This is a nasty side effect. Be very careful when listening, because you can also be interfering with a nearby listener.

The regeneration control is very sensitive. You must very careful adjusting it before the thing goes into oscillation. The maximum sensitivity point is just before the start of oscillation.

The audio amplifier is a LM386. The sound quality is good but the volume is somewhat low.