Solar radio (CB20485E)

This circuit is from a 1991 publication. The integrated circuit used is an integrated radio from that era.

NE602 Converter (CB25304E)
This circuit converts signals from the longwave band of 350 kHz to 500 kHz to 4.35 to 5MHz. The...
LM741 100 Hz Second Order High Pass Filter (CB25934E)
This filter was found in the May 1989 issue of Radio Electronics magazine. The power supply must...
Word Compressor MC1490P (CB4497E)
The integrated circuit used is not very common today. Transistors can be replaced by more modern...