Band conditions
Clean Morse code almost never arrives on shortwave. Practice only under good conditions and you will think you are better than you are.
Why this is the real difference
Recognizing characters in a clean tone and recognizing them in noise are two skills. The second is the one that matters, and it can only be practiced when the noise is there.
The reason is not toughness but the way hearing works. Under interference the ear fills in what is missing - but only if it expects the character. Someone who knows the characters only clean has nothing to fill in with and hears fragments. That is why people who have practiced solely on a trainer often fall apart on their first real contact.
The eight conditions
- Clear. It never sounds like this. Still right for learning the characters.
- Weak signal. Noise beneath the tone - the most common case of all.
- Fading (QSB). The signal comes and goes as the path through the ionosphere shifts. Waiting helps more than turning it up.
- Atmospherics (QRN). Thunderstorm crashes. On 80 and 40 meters in summer, the normal state.
- Another station (QRM). Someone else alongside. Solvable, because they sit at a different pitch.
- Frequency offset. The tone is not where you expect it. Tuning across is enough - but you have to notice.
- Crowded band. Contest weekend: everything at once, none of it fatal.
- Extreme. So bad that giving up would be reasonable. Sometimes it still works.
Why the interfering stations sound different
The other stations deliberately do not sit at the same pitch as the wanted signal. That is exactly what makes QRM solvable: the ear separates by pitch better than by anything else, and once the filter is in your head you hear straight past it.
A receiver has a real filter for this, cutting away everything outside a narrow strip. The ear can do it too - it just has to be taught, and that is what this page is for.
What the difficulty means
The bar beside each condition is set, not measured. What is hard to hear depends on the ear, on practice and on the headphones, and cannot be computed.
The weights are in the source as numbers all the same, not merely as an order: noise and other stations weigh heaviest, a pitch offset least, because you tune it away and then it is gone. That way the grading is verifiable rather than claimed.
Frequently asked questions
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Which condition should I practice on?
The one that still just carries you. If you get everything on "weak", move to "fading". If you already fall apart on "clear", stay there - noise does not make a character easier that is not solid yet.
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Is that real noise?
It is white noise generated in the browser, not a recording. That is more honest than it sounds: real band noise is nothing else either, except that thunderstorms, power supplies and the neighbor join in. The crashes are added here on purpose.
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Why is "crowded band" not the hardest?
Because many stations do not mask one another as long as they sit at different pitches. What is genuinely hard is a weak signal with fading - there is nothing left for the ear to hold on to.