This receiver is from a 1924 Gernsback publication. The receiver has good efficiency when powered by the indicated voltages. Listening is through a high-impedance phone.
This power supply with transistor regulation was obtained in a 1995 documentation. The power...
This two-station intercom was found in documentation from 1966. R4 should be experimentally...
We found this circuit in a publication from 1966. The components are from the period. Complete...