All-bands single-signal filtered regenerative detector

This is a minimal all HF bands regenerative detector, I designed initially to be used as an ultra low components SDR receiver. However, because of it's low sensitivity, I mostly use it as a detector in lab projects. This is a filtered, regenerative detector, that is capable of receiving single signal (USB), due to it's very smooth regeneration. The crystal can be replaced by a ceramic resonator as well, if more tuning range is needed. The crystal/resonator, acts both as the resonator for the oscillator, as well as an RF filter. It should eliminate intermodulation products that could be caused by the strong signals, which could otherwise be detected by the active device. A varicap could be used in place of the variable capacitor, but I wanted minimum parts count, so I left the variable capacitor in place.