PTT or Push to Talk is the control that switches the speak-hear function on a transceiver. This circuit was found in the magazine of radio amateurs 73, in an edition of the 90s.
We found this circuit in a European publication from the 1970s. The transistors are made of...
The TAA131 used in this circuit is not very easy to find today, but an equivalent low power audio...
This circuit was suggested by National Semiconductor in its Linear Application Handbook. The...