For FB group Building Transistor Radios
Darrell Darby (Schematic below)
What amazes me is the collector load resistor for the earphone stage is 100k. That’s more than ten times higher than usual, and it’s okay because the crystal earplug is very sensitive.
I would squeeze a bit more gain out of it by removing the 220k and changing the 1 meg to a 4.7 Meg or 10 Meg. The 2N4401 is a general purpose NPN, you can use a BC547, PN2222A or 2N3904.
