We’ve been loving the variety of entries to the 2025 One-Hertz Challenge. Many a clock has been entered, to be sure, but also some projects that step well outside simple timekeeping. Case in point, ...

The average textbook definition of modulation reads: modulation is a process in which the frequency, phase or amplitude of a carrier wave varies in step with the instantaneous value of the modulating ...

The author, WA2EWT, is a broadcast consultant in St. Petersburg, Fla. The FCC has formally approved a “green” technique for AM radio stations that want to reduce their operating costs. The technique ...

Last month we looked at contributions to the art made by amateur operators, in particular advancements in Amplitude Modulation, or AM, and how it came to give radio its voice. This month, we will look ...

The mode of operation of the amplitude-modulated transmitter Class-C output stage is discussed, with particular references to the case where the load impedance varies over the working frequency band; ...

The proposed CORDIC-less digital polar transmitter demonstrates superior power added efficiency (PAE) and system efficiency (SE) for similar modulation signals. It also supports wider bandwidths, ...