How do I use the Reverse Beacon Network to test an antenna?

Call CQ on one antenna, wait about 60 seconds for spots to populate on reversebeacon.net, then switch antennas and call CQ on a nearby frequency at the same power. One documented test compared a 20m delta loop on 14.032 against a dipole on 14.034 and showed the loop 3-4 dB stronger into Europe. Compare reports from the same skimmer node, since propagation shifts minute to minute.

Does the Reverse Beacon Network spot SSB stations?

No. CW Skimmer decodes only Morse and RTTY, and SSB would require speech to text plus reliable callsign extraction, which nobody has deployed at scale. FT8 and FT4 operators get equivalent coverage through PSKReporter using WSJT-X reporting, while SSB operators still rely on human spotters and self-spotting systems such as the POTA and SOTA spot tools.

What hardware do I need to run my own skimmer node?

A Windows PC as modest as a 2015 i5 handles single-band skimming, plus an HF SDR, a decent receive antenna such as a horizontal loop or broadband vertical, CW Skimmer or MultiSkimmer, and an internet connection. Receiver options range from a $30 RTL-SDR for one narrow band to an AFEDRI AFE822 at $280, a QS1R at $500, or an RSPdx at $200 covering 160m to 6m through its 10 MHz bandwidth.

Is using CW Skimmer legal for amateur radio?

Yes. It is only a receiver and decoder, and FCC Part 97 does not restrict what you do with signals you receive. The only issue is contest rules: using spots while entered in an unassisted category breaks the contest rules, not FCC regulations, so check the category definitions for each event.

How is the RBN different from a traditional DX cluster?

DX clusters like DXSummit and AR-Cluster depend on a human hearing a station and typing a spot. The RBN is fully automated, so spots appear in seconds rather than minutes, coverage runs 24/7 regardless of who is at a radio, every CQ gets spotted rather than only rare DX, and each spot includes signal-to-noise data that clusters do not provide.

Why is my callsign not showing up on the Reverse Beacon Network?

The decoder expects consistent element timing, so badly spaced or speed-varying CW can be garbled or missed entirely. Use the standard CQ CQ CQ DE CALL CALL K structure, keep speed in the 20-28 WPM sweet spot, send at least two full CQ sequences instead of one quick call, and avoid frequencies at the extreme edges of common SDR passbands such as exactly 14.000 or 14.350 where some nodes roll off.

Does the RBN work for phone/SSB?

No. CW Skimmer only decodes Morse and RTTY. SSB decoding would require speech-to-text plus callsign extraction, which is a much harder problem. Nobody has deployed this at scale yet.

Can the RBN decode my callsign if I'm sending poorly?

It's surprisingly tolerant of imperfect CW, but if your spacing is way off or you're sending at inconsistent speed, it may garble your call or miss it entirely. The decode algorithm expects consistent element timing.

CW Skimmer and Reverse Beacon Network: Letting the Internet Find Your Signal

You call CQ on 14.035 MHz. Within 30 seconds, without anyone physically hearing you and manually posting a spot, your callsign appears on a worldwide map showing exactly which stations decoded your signal and at what strength. No cluster needed. No buddy to spot you.

Street prices in this article were checked in August 2026 and move around; verify with a dealer such as HRO, DX Engineering, or GigaParts before you buy.

That's the Reverse Beacon Network. And it fundamentally changed how CW and RTTY operators understand propagation, test antennas, and get noticed by DX stations.

What CW Skimmer Does

CW Skimmer (developed by Alex Shovkoplyas, VE3NEA) is Windows software that decodes every CW signal across an entire receiver's bandwidth simultaneously. Not one signal at a time — every signal. Feed it the I/Q output from an SDR with 192 kHz bandwidth, and it'll decode 50+ CW QSOs happening at once.

The software uses matched filtering and pattern recognition to identify callsigns in the CW stream. It decodes CQ calls, pulls out the callsign, measures the signal-to-noise ratio, timestamps it, and reports it.

A single CW Skimmer instance watching 20m can decode dozens of stations per minute during a contest. The Pro version handles up to 7 SDR receivers simultaneously, covering multiple bands.

CW Skimmer requires a license ($75 for the standard edition, $150 for Pro). It runs on Windows and needs an SDR receiver — anything from an RTL-SDR dongle ($30, limited bandwidth) to a high-performance SDR like the AFEDRI AFE822 ($280, dual-channel, up to 2 MHz bandwidth) or the QS1R ($500, designed specifically for skimmer use).

How the Reverse Beacon Network Works

The Reverse Beacon Network (RBN, reversebeacon.net) aggregates spots from CW Skimmer stations worldwide. As of mid-2025, there are typically 100-200 active skimmer nodes running at any given time, spread across North America, Europe, Asia, and Oceania.

When you call CQ on CW (or RTTY — the RBN also decodes RTTY via the SkimSrv software), every skimmer node that can hear you reports:

Your callsign
Frequency
Signal strength (in dB SNR)
Timestamp
Speed (WPM)

All of this posts to reversebeacon.net within seconds. You can search your callsign and see, in real time, which skimmers heard you and how strong you were.

I ran a test last fall that drove this home for me. I'd just put up a new 20m delta loop and wanted to compare it against my old dipole. Instead of running QSOs and collecting signal reports (which are subjective and unreliable), I called CQ on 14.032 on the delta loop, waited 60 seconds for RBN spots to populate, then switched to the dipole and called CQ on 14.034. Same power, same time, same propagation. The RBN spots showed the delta loop consistently 3-4 dB stronger into Europe and about equal into South America.

Done. Antenna comparison completed in five minutes with objective data. No need to find a cooperative station on the other end.

Practical Uses for the RBN

Antenna Testing

This is the killer app. Call CQ, check your spots. Change something. Call CQ again. Compare.

Some caveats: propagation changes minute to minute, so you want to switch quickly. And the SNR values from different skimmer stations aren't directly comparable (different antennas, different noise floors). Compare the same skimmer node's report of your two antennas for meaningful A/B data.

Propagation Monitoring

Before calling CQ on 30m at 2200 UTC, check reversebeacon.net to see which stations are being heard on that band right now. If European skimmers are decoding US stations, the path is open. If not, try a different band or wait.

The RBN effectively gives you a live propagation map without needing to make a single contact.

Contest Preparation

Big gun contesters use the RBN to verify their station is working correctly before a contest starts. Call CQ during a pre-contest warmup, confirm you're being spotted at expected levels, identify any band where you're weak (suggesting an antenna problem).

During contests, the RBN feeds into cluster aggregators. If you're running (calling CQ repeatedly), the RBN ensures you show up on DX cluster networks automatically, which drives callers to your frequency. Seriously powerful for contest rate.

Finding Your Signal's Reach

RBN spot maps show geographic coverage. I've used this to figure out that my 40m vertical is great toward South America but weak into Japan — exactly what you'd expect from its radiation pattern and my feedline routing creating slight directivity.

Setting Up Your Own Skimmer Node

Want to contribute? A basic skimmer station needs:

A Windows PC (can be older — a 2015 i5 handles single-band skimming fine)
An SDR receiver covering HF (RTL-SDR for single narrow band, or something with wider bandwidth)
A decent receive antenna (a horizontal loop or broadband vertical works well)
CW Skimmer or MultiSkimmer software
Internet connection for uploading spots to RBN

The RBN aggregator (Telnet feed at port 7000 of reversebeacon.net) accepts spots from registered stations. You register your callsign with the RBN project, configure CW Skimmer's spot output to report to the network, and you're live.

The most productive skimmer nodes run 24/7 on dedicated hardware with broadband SDRs covering multiple bands simultaneously. Stations like K3LR's skimmer array use multiple AFEDRI or QS1R SDRs, each covering one or two bands, feeding into CW Skimmer Pro instances.

A thread on r/amateurradio last year discussed budget skimmer setups. Several people reported success with the RSPdx ($200) covering 160m-6m simultaneously via its 10 MHz bandwidth, feeding into MultiSkimmer. That's a lot of band coverage from one SDR.

RBN vs DX Cluster: What's Different

Traditional DX clusters (like DXSummit or AR-Cluster) rely on human operators manually spotting stations. Someone hears 3B8XF on 20m CW, types a spot, and it propagates through the cluster network.

The RBN is automated. No human in the loop. This means:

Spots appear faster (seconds vs minutes)
Coverage is consistent (active 24/7, not dependent on who's at their radio)
SNR data is included (clusters just give frequency and callsign)
Every CQ gets spotted, not just rare DX

The downside? The RBN only decodes CW and RTTY. It doesn't spot SSB stations (it can't decode voice), and it doesn't spot FT8/FT4 — those have their own reporting network via PSKReporter.info, which works on the same principle but using WSJT-X's built-in reporting.

FT8 operators have PSKReporter. CW operators have RBN. SSB operators have... well, they still rely on human spotters and self-spotting apps like SOTA Spotter or POTA's spot system. Life isn't fair.

The Controversy: Is RBN Cheating?

Some contesters argue that the RBN gives CW operators an unfair advantage — they get automatically spotted while SSB operators don't. Contest rules vary on this. Some contests allow assisted (cluster/RBN) operation as a separate category. Others are "unassisted" where you're not supposed to use spots.

But here's my take: the RBN spots you when you call CQ. You're not using it to find stations — other people are finding you through it. Whether that's "assisted" is a philosophical debate the contest community hasn't fully resolved.

For non-contest use? There's zero controversy. It's a tool. Use it.

Tips for Getting Good RBN Coverage

Send CQ at 20-28 WPM. Skimmer decodes reliably from about 15 to 40+ WPM, but 20-28 is the sweet spot for consistent detection.
Use standard CQ format: "CQ CQ CQ DE [CALL] [CALL] K" — the skimmer's pattern matching expects this structure.
Call CQ at least twice in succession. A single CQ might get missed if the skimmer's noise blanker is processing another signal.
Avoid frequencies right at the edge of common SDR bandwidths (e.g., exactly 14.000 or 14.350) where some skimmer stations may have rolloff.

Sending your call once quickly and moving on? The skimmer might miss you. Give it two CQ sequences minimum.

What This Means for Your Operating

If you operate CW at all, the RBN is working for you right now whether you use it or not. Every time you call CQ, skimmer stations hear you and report you. Your callsign shows up in feeds that DX chasers and contesters monitor.

The actionable part: check reversebeacon.net regularly. Use it to test antennas, verify propagation paths, and understand your station's actual reach. It's free, it's real-time, and it gives you objective data that no amount of on-air signal reports can match.