This circuit is from documentation from 1965. However, it can be created with modern transistors. Power comes from two 9 V batteries.
We found this code switch circuit in the January 1999 Electronics Now magazine. Some of the...
January 2017 - Now available on Mouser Electronics, Texas Instruments' new LDC2114EVM Evaluation Module...
This circuit with a CA3018 from RCA at the time was found in the August 1970 issue of Radio...