Welcome to Issue #009 of Radio Waves Weekly! This week: CY0S has touched down on Sable Island — North Atlantic rare DX on the air right now. VOA has quietly returned to shortwave. A VU ham completed QRP DXCC on a transceiver he designed and built himself. Plus a crisp AGC fix for uBITX owners, the right way to wind a 1:49 UNUN, a $50 wideband SDR built from scratch, CQ WPX SSB in six days, and the ARRL Coding Competition with $25,000 on the table.
1. CY0S — Sable Island Is on the Air Right Now, QRV Through March 31 DX ALERT
The CY0S team made it to Sable Island after a helicopter delay and is now active through March 31 across HF. Sable has no permanent residents, sits at #30 on the ClubLog Most Wanted list, and is accessible only under strict Parks Canada permits — activations happen rarely. Operations cover 160–10m on CW, SSB and FT8 with daily log uploads. VU stations should watch 20m and 17m long-path between 0200–0500 UTC. OQRS and real-time log access are on the news page.
Live updates, frequencies & OQRS → t-rexsoftware.com/cy0s/news.htm
2. WN5C Completes QRP DXCC on a Transceiver He Designed Himself HOMEBREW QRP
Sam WN5C spent eight months working 100 DXCC entities at 3–5 watts on the “Thunderbird” — a multiband CW superheterodyne he designed from scratch, including the receiver, PA, and low-pass filters. The final entity came via a Guinea-Bissau pileup on 10m at 3W. Published March 10 on QRPer.com, his account covers the engineering decisions, the field failures in New Mexico heat, and what actually made the difference between working and missing rare DX at QRP. Honest, detailed, and genuinely inspiring for anyone with a soldering iron.
3. KV4AN’s QMX Field Kit — Adding 80m and 60m to a Lean Portable Setup QRP FIELD KIT
Steve KV4AN details his compact POTA kit built around the QRP Labs QMX Low Band (80–20m), chosen specifically because his other portable radios already covered 40–15m and Solar Cycle 25 will not last forever. The writeup covers the full kit layout, how the QMX handles 80m on Parks on the Air activations, and the tradeoffs between the three QMX band variants. Published March 14 on QRPer.com, it is a practical reference for any operator assembling a multiband portable kit around current QRP Labs hardware.
Field kit writeup → qrper.com/2026/03/kv4ans-comprehensive-qmx-field-kit/
4. VOA Returns to Shortwave — Yankee Doodle Heard Again on 7500 kHz HF NEWS
On March 1, contributor Dan Greenall reported to SWLing Post that he heard Voice of America’s Yankee Doodle signature on 7500 kHz for the first time in years — a Mandarin language service via the Tinang, Philippines transmitter. Further reports confirmed Korean on 9310 kHz the same week. After years of US court battles, VOA’s shortwave presence is partially restored. For VU operators and SDR monitors, the Tinang transmitter is receivable across South Asia at reasonable signal levels during the late UTC evening.
5. VK3YE’s AGC Circuit for the uBITX — One Op-Amp, Huge Improvement CIRCUIT BUILD
The uBITX family has no automatic gain control in its stock form — strong signals clip the audio hard and weak ones disappear. VK3YE’s simple AGC retrofit uses a single op-amp in a peak-detector envelope-follower configuration, feeding a JFET or PIN diode attenuator ahead of the IF chain. The circuit is powered from the existing 12V rail, installs without any modifications to the uBITX PCB, and can be switched in or out in line. Full schematic, component values, and fitting notes are documented on vu3dxr.in.
Circuit and fitting guide → vu3dxr.in/vk3yes-agc-circuit-for-ubitx/
6. 1:49 UNUN Using Stacked FT240-43 Cores — Wind It Right the First Time ANTENNA BUILD
The 1:49 impedance transformer is the heart of every end-fed half-wave (EFHW) antenna, and the core choice matters enormously. This guide covers winding the UNUN on two stacked FT240-43 toroids — the stacking doubles effective core volume, reduces core saturation at QRO power levels, and cuts insertion loss compared to a single smaller core. Turn count, wire gauge, winding technique, and power handling results are documented with test data. Essential reading before building any EFHW for 40–10m use.
7. $50 SDR with 20 MHz Bandwidth — Built on a Budget from Scratch SDR BUILD
Published today on Hackaday: [Aaron] built a direct-conversion SDR receiver covering 1–6 GHz with 20 MHz instantaneous bandwidth for around $50 in components, using a RFFC5072 wideband synthesiser, an AD8333 IQ demodulator, and a Raspberry Pi Pico for USB audio. At this bandwidth, it captures an entire amateur satellite downlink passband or a full ADS-B channel in a single sweep. GNU Radio compatible. Schematic and firmware are on GitHub.
Build article and GitHub links → hackaday.com/2026/03/22/building-a-50-sdr-with-20-mhz-bandwidth/
8. CQ WPX SSB — 48 Hours of Prefix Hunting, This Weekend March 28–29 CONTEST
CQ WPX SSB runs 0000 UTC Saturday through 2359 UTC Sunday on 160–10m. Every unique callsign prefix is a separate multiplier — over 35,000 active prefixes worldwide means the hunt never slows. Key 2026 rule change: logs must be submitted within 48 hours, no later than 2359 UTC March 31. For VU stations, 15m and 10m should deliver productive runs toward Europe, Japan and South America at current Solar Cycle 25 levels. Even a few hours in the chair is worth the log points.
Rules and log submission → cqwpx.com/rules/
9. SpottedHam.com — New Real-Time DX Cluster with Embeddable Widgets DX TOOL
Launched February 14, SpottedHam.com is a modern DX spotting platform aggregating spots from multiple cluster networks with a mobile-first interface, band and mode filters, and custom callsign alerts. Uniquely, it offers embeddable live-activity widgets for club websites. With CY0S active now and CQ WPX SSB this weekend, this is a practical tool to run alongside your logging software. Worth bookmarking especially ahead of Sporadic E season in April.
Live DX cluster → spottedham.com
10. Ham Radio Open House April 2026 — Show Your Station, World Amateur Radio Day April 18 UPCOMING EVENT
ARRL’s second annual Ham Radio Open House runs throughout April, centred on World Amateur Radio Day April 18 — the date in 1925 when the IARU was founded in Paris. Clubs and school stations are invited to open to the public: demonstrate FT8 on a waterfall display, show a satellite pass, or run a POTA activation. The ARRL Open House Locator map lets clubs register their events and the public find a shack to visit. For VU clubs, this is an excellent opportunity to introduce the STEM dimension of amateur radio to a wider audience.
Registration, locator and event details → arrl.org/world-amateur-radio-day/
11. ARRL Student Coding Competition 2026 — Up to $25,000, Deadline March 31 COMPETITION
ARRL launched its first Student Coding Competition on January 1 with prize awards up to $25,000 for software tools that advance amateur radio. Entries must meet published technical specifications at coding.arrl.org; submissions close March 31, 2026. Judging criteria include specification compliance, usability, code quality and extra features. ARRL Student Membership is free for full-time students aged 21 and under. A rare incentive for young hams with programming skills to build something lasting for the hobby.
Competition rules and submission → coding.arrl.org
12. Environment Canada Weatheradio Permanently Shut Down March 16 VHF NEWS
Environment Canada closed its Weatheradio and Hello Weather VHF services permanently on March 16, ending continuous weather broadcasts that covered over 90% of Canadians. Dedicated Weatheradio receivers are now silent. For SDR operators who use VHF monitoring as a hobby or for propagation assessment, this removes a reliable continuous carrier on the 162 MHz Weather Radio band. The SWLing Post covered the shutdown with full details on what was lost and what ECCC is directing listeners to use instead.
Want to contribute? Found an interesting circuit, a new SDR software, a helpful radio blog, or breaking ham radio news? Email me or leave a comment below. Your link might be featured in next Sunday’s digest!
