This circuit appeared in Amateur Radio Today in an issue and was found in a 1995 issue. The circuit is for the AM band up to 3 MHz. The transistors are general-purpose.
This circuit is from an old Japanese magazine from 1960. The circuit uses germanium transistors from the...
This is the factory setting (National Semiconductor) of the TDA2006 as an audio amplifier. The...
This circuit can use a pendulum sensor. We found this configuration in a 1994 publication. The...