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.
This circuit is from an old manual, but can be easily assembled as the integrated one is still...
The simple transistor test shown in the figure can be powered by a 9V battery. The test is for...
This regulator can use BD'136 as the main transistor and as a reference next to a BC548 zener. The...