Found in a 1988s Radio Electronics, this circuit uses transistors of general use to increase the intensity of signals up to about 30 MHz. The power can be done by battery because the consumption is low.
This circuit is from Popular Electronics from October 0, 1981. The diodes can also be 1N4004 and...
This switch or band selector for receivers was found in a Popular Electronics from the 1990s. The...
This circuit, published in 1978, can use any general purpose NPN transistor such as the BC548 and...