Ham Radio General Class Test 2026 – 400 Free Practice Questions to Pass the Exam

The term "software defined radio" (SDR) refers to a radio system where the majority of its signal processing functions are accomplished through software rather than traditional hardware components. This allows for greater flexibility and adaptability in managing and modifying radio operations.

With SDR, users can easily update and enhance the performance of the radio by changing the software rather than needing to physically alter or replace hardware components. This capability is particularly beneficial for amateur radio operators, as it allows them to experiment with different modulations, frequencies, and protocols by simply updating the software, keeping up with technological advancements more efficiently.

The other options highlight aspects related to radio technology but do not accurately define SDR. While automatic logging and interface capabilities, crystal filters, and computer simulations play important roles in radio operations, they do not encapsulate the primary characteristic of software defined radios, which is the reliance on software for core processing and functionality.