Using the 2N2646 this circuit was found in a Radio Electronics magazine from July 1968. The transistors are from the time and the lamp can be replaced by a high-power LED in a current version.
This circuit makes use of comparators and common operational amplifiers, having been found in...
Standing wave ratio or SWR is an important measure of whether all power from a transmitter is being...
A configuration using three of the four voltage comparators on the LM339 is shown in the figure and...