{"id":592,"date":"2025-11-12T11:57:10","date_gmt":"2025-11-12T10:57:10","guid":{"rendered":"https:\/\/www.hamlinux.it\/en\/?page_id=592"},"modified":"2026-03-23T13:40:51","modified_gmt":"2026-03-23T12:40:51","slug":"radio2","status":"publish","type":"page","link":"https:\/\/www.i8zse.it\/en\/radio\/radio2\/","title":{"rendered":"Choose the radio"},"content":{"rendered":"

The Heart of the Station: Choosing the Right Radio<\/h2>\n

As we\u2019ve seen, the radio transceiver is truly the heart of any amateur radio station<\/strong> \u2014 and thus deserves careful consideration according to the operator\u2019s goals and, of course, their budget.
\nThe market offers a wide range of new models as well as a very active second-hand ecosystem, which can be both a blessing and a source of confusion, especially for newcomers.<\/p>\n

Here I\u2019ll share my personal point of view on what I consider to be the most important aspects<\/strong> to evaluate, in order to provide a more objective way to compare different radios.
\nI should emphasize that all of these reflections are strictly personal<\/strong>: this space contains no advertising \u2014 neither direct nor disguised.<\/p>\n

This overview refers specifically to HF (High Frequency)<\/strong> equipment, which is usually the most fascinating range for those entering the world of amateur radio.<\/p>\n

\n

Architecture<\/h3>\n

The traditional superheterodyne<\/strong> design, despite being nearly a century old, remains a benchmark in receiver architecture.
\nThe incoming RF (radio frequency) signal is converted through one or more mixing stages<\/strong> to one or more fixed intermediate frequencies (IF)<\/strong>, where most of the amplification and filtering occur.<\/p>\n

SDR (Software Defined Radio)<\/strong> transceivers, on the other hand, represent a major paradigm shift, moving much of the signal processing from the analog to the digital domain.
\nAfter minimal analog conditioning, the RF signal is digitized<\/strong> and then processed entirely in software<\/strong>.<\/p>\n

The advantages of SDR architecture lie in its flexibility<\/strong>, upgradeability<\/strong>, and the ability to monitor wide portions of the spectrum<\/strong> simultaneously.
\nHowever, real-world performance still depends on implementation quality, as both architectures have specific strengths and limitations.<\/p>\n

\n

Sensitivity<\/h3>\n

When evaluating radios, I always prioritize the receiver section<\/strong>, since it\u2019s the most crucial: you must first hear<\/strong> the other station before you can work it.
\nThe main specification is sensitivity<\/strong>, or the ability to detect very weak signals.<\/p>\n

A sensitive receiver can discern faint signals even when they\u2019re close to the background noise level.
\nThis concept relates directly to the signal-to-noise ratio (S\/N)<\/strong> \u2014 like hearing a whisper in a quiet room versus trying to listen in heavy traffic.<\/p>\n

Sensitivity is therefore linked to the receiver\u2019s ability to maintain a good S\/N ratio with very low-level signals.
\nAnother important factor is bandwidth<\/strong>: the wider it is, the more noise passes along with the signal.
\nNarrower bandwidths reduce noise and improve sensitivity \u2014 but if the filter is too narrow, part of the signal itself is lost.<\/p>\n

For CW (Morse)<\/strong> operation, narrow filters yield excellent performance, while AM (Amplitude Modulation)<\/strong> requires wider filters, which naturally collect more noise.<\/p>\n

In summary, a receiver\u2019s sensitivity depends on:<\/p>\n