Listen first

You don't need a license to listen. You don't even need a radio: volunteers run hundreds of receivers around the world that you can tune from a browser. An hour of listening teaches you how real contacts sound, when bands are open, and what a POTA pileup feels like. It also makes the Technician exam questions make more sense.

Independent guide, not affiliated with WebSDR, KiwiSDR, OpenWebRX, RTL-SDR or any receiver owner. Online receivers are run by volunteers: be gentle with them.

Listen first v1.0 · written 2026-10-08 · links and satellite status checked as of Oct 2026

Three ways to listen

Online receivers

• WebSDR sites show a waterfall for each band. Click a signal to tune it. Many listeners can share one receiver at once. The list at websdr.org shows each site's location and bands. The University of Twente receiver in the Netherlands is the famous one.
• KiwiSDR receivers cover 0–30 MHz, and each one allows a few users at a time. The receiver list lets you pick one near a station you want to hear. If one is full, try the next.
• OpenWebRX is software some owners use for their receivers. It's the same idea, with a different look.

Pick a receiver far from the station you want to hear, because HF signals skip. A receiver 500–1,500 miles away usually hears a 40 m or 20 m station better than one next door.

What to tune for

Voice on HF uses single sideband: LSB below 10 MHz, USB above 10 MHz. 60 m is the exception and uses USB. If a voice sounds like a duck, you're on the wrong sideband or slightly off frequency.

Band edges and segments: ARRL band plan. How bands open and close: Technician HF & propagation.

Five listening exercises

1. Find a POTA activator. Open the spots on pota.app, pick an SSB spot on 20 m or 40 m, and tune a receiver a few states away to that frequency. Listen to how the activator runs the pileup: short exchanges, a park number and "QRZ?". Then read Hunt.
2. Copy a full contact. Write down both call signs, the signal reports and the names. That's what you'll log once you're on the air.
3. Listen to a contest weekend. The bands are packed and exchanges are seconds long. Good practice for hearing call signs through noise. See Contesting.
4. Follow a net. Hear how a net control station runs check-ins. See Clubs & Elmers.
5. Hear the ISS. When the space station runs an SSTV event or a school contact, you can hear it overhead on 2 m with a handheld or RTL-SDR. Check ARISS and our SSTV and Satellites pages.

RTL-SDR: a cheap software radio

An RTL-SDR is a USB dongle, originally a TV tuner, that turns a computer into a wide-band receiver. With a simple antenna it covers VHF and UHF well. Some models add an HF direct-sampling mode, which is usable but no match for a real HF receiver. The RTL-SDR quick start guide walks through drivers and software.

Good first projects:

• Local repeaters and simplex on 2 m and 70 cm. Get frequencies from RepeaterBook.
• NOAA Weather Radio around 162.4–162.55 MHz.
• Aircraft: voice on the airband, and ADS-B position reports at 1090 MHz plotted on a map.
• Satellites: FM amateur satellites and the ISS on 2 m and 70 cm. Old tutorials describe NOAA APT weather pictures at 137 MHz, but NOAA decommissioned the last of those satellites in 2025 (NOAA-19 on Aug 13 and NOAA-15 on Aug 19, after NOAA-18 was retired in June). NOAA NESDIS has the details. Don't buy gear for that project.

Receiving is fine without a license. Transmitting is not. An RTL-SDR can't transmit, so it's a safe toy.

Scanners, public safety and ships

• Scanners. Many police, fire and EMS agencies use trunked and digital systems such as P25, so an old analog scanner may hear nothing. The RadioReference database lists the systems and frequencies near you, which tells you which scanner you need. Broadcastify streams many of the same feeds online. Some agencies encrypt, and nothing legal will decode that.
• Know your state. A few states restrict scanners in vehicles, often exempting licensed hams. Federal law also limits what you may share or use from what you overhear. Listen, but don't repeat or act on it.
• Ships (AIS). Vessels broadcast their position on 161.975 and 162.025 MHz. An RTL-SDR with free decoder software can plot nearby ships on a map, the maritime version of ADS-B.

After you're licensed: hear yourself

Online receivers are just as useful once you transmit. Call CQ, then listen on a KiwiSDR or WebSDR a few hundred miles away to hear what your signal sounds like there. It's the fastest way to check an antenna or a park setup. For CW and digital modes, the automatic spotting networks do the same job. See Technician HF.

Next step: the license

When listening turns into "I want to answer that," study for the Technician exam (Element 2). Our Ticket to Talk practice runs in your browser and is free for all three license classes. Fees, sessions and call signs are on What a license costs.

Habits / gotchas / checklist

• Choose a receiver far enough away to hear the station via skip.
• LSB below 10 MHz, USB above (60 m is USB).
• Don't hog a KiwiSDR slot. Close the tab when you're done.
• Write down the call signs you hear. It trains your ear for logging.
• RTL-SDR: start with local repeaters and NOAA Weather Radio, not NOAA APT satellites (retired in 2025).
• Licensed? Use a distant online receiver to check your signal after every antenna change.