This circuit was found in a British documentation from 1969. It can be implemented with modern transistors. The pass band is 6 MHz.
This circuit was found in the November 1966 issue of Electronics Now magazine. It uses an LDR as a...
In the figure we show how a 2-pole x 2-position switch or HH should be connected to reverse the...
We found this circuit in the March 1980 Radio Electronics magazine. The circuit used is the HA2400...