This amplifier for the 10 m (30 MHz) band has a gain of 12 to 15 dB having been found in an American documentation. Other RF transistors can be used like 2N2222 or 2N2218.
This circuit was found in a Texas Instruments optoelectronics documentation. The gain depends on...
This oscillator circuit is from a Radio Electronics magazine from September 1960. The frequency depends...
Using a reed relay, this protection circuit depends only on the adjustment of the closing point by a wire...