Identify two HF signals and describe how their reception differs.
Before you begin
Prerequisites
- A computer or phone with internet access
What you need
- A browser-based SDR with HF coverage
- Headphones (optional)
- A place to record frequency, time and mode
Work through the steps
Use the checks as a personal or mentor-led review. You can print this page and mark each one as you go.
Select a receiver
Open an available public WebSDR or KiwiSDR. Read the receiver rules and choose an HF amateur band.
Verify: You can tune and hear receiver audio.
Find voice activity
Try a band used for voice at the current time. For amateur SSB, select the appropriate sideband and adjust tuning until speech is intelligible.
Verify: You can record one frequency and the mode you heard.
Explore another band
Compare reception on a second band or at another time of day. Watch how signals and noise change.
Verify: You noted a second signal or a clear difference in activity.
Explain the observation
Write two sentences about distance, propagation, band occupancy or interference. Do not assume a single reception proves propagation conditions everywhere.
Verify: You can describe an observation and a plausible explanation separately.
Safety and operating limits
- This is receive-only; no amateur radio license is needed to listen where legally permitted.
- Do not rely on reception observations to predict emergency communications reliability.
Trusted starting references
Choose an internet-connected receiver and tune it in your browser. Listen through its remote antenna before buying equipment or making a transmission.
WebSDR directoryUse the map to choose a public KiwiSDR in another location. Compare what that receiver hears with a second site or a different time of day.
KiwiSDR public receivers
Where to go next
Compare propagation forecasts or pair this with a supervised HF station visit.