What attracts a lot of people to amateur radio is that it gives you the ability to make your own gear. Scratch-building hams usually start by making their own antennas, but eventually, the itch to … ...

Semiconductors, Photoconductivity, Electronic Transport, Amplitude Modulation. ... (IA) was built by using a field effect transistor OPAMP TL081 as shown in Figure 1. In such a circuit, if the I bias ...

The efficiecy of a class A amplifier is very low: 25% at maximum output amplitude and even less at low signal levels. The efficiency can be improved by using a symmetrical design with 2 transistors, ...