AmateurRadio.com

Greetings Olivia and digital mode operators,

GREAT NEWS! WEBSITE UPDATE!

Here are the big three new features:

Live spotting is now available!

1. Live Olivia spotting. Just like on POTA and other sites, this is a live show and tell of your activity either by self spotting, or spotting stations you copy. Dedicated live spot page, you can view even on a cell phone.

   We are excited to announce a major new feature now live on OliviaDigitalMode.org: an interactive Live Station Spotting tool designed specifically for our digital HF community. Inspired by popular spotting platforms like DXWatch and POTA.app, this system makes it easier than ever to see who is active on the bands, find open Olivia QSOs, and share your own station reports in real time.

   Come Join the Live Spotting of Olivia Digital Mode

   Whether you are hunting for a contact or tracking band openings across different bandwidths and tone counts, the new spotting tool brings several powerful capabilities straight to your browser:

   • Real-Time Live Feed: The spotting page automatically refreshes every 15 seconds, ensuring you always see the latest on-air activity without needing to manually refresh the page.
   • Smart Spot Grouping: When multiple operators spot the same station, the system automatically groups those reports together into a single clean line. Instead of duplicate entries cluttering your view, you will see the station, frequency, mode, and a list of all operators who spotted them.
   • Timeframe Visual Highlighting: You can easily filter for fresh activity. By selecting a window of 5 minutes, 15 minutes, 30 minutes, or 1 hour, brand-new spots are visually highlighted so you can jump on active signals immediately.
   • Flexible Display Options: On the dedicated spotting page, you can choose how many spots to display at once (from 10 up to 250 rows) and toggle between a grouped callsign layout or a detailed chronological log.
   • At-a-Glance Homepage Widget: A lightweight summary widget on the main homepage shows the top 5 to 10 most recent spots the moment you arrive on the site.
   • Fast Performance and Historical Archives: Active spots stay on the main board for 12 hours to keep queries ultra-fast. After 12 hours, spots automatically move to a historical archive where they remain available for band activity research and propagation analysis.

   To keep the spotting board reliable and free of spam, posting new spots will require a simple, free operator account. When you register, you will just need to include a short note for the site administrators to verify your callsign and approve your posting access. Once approved, you can log in anytime and share spots whenever you are on the air.

2. Live Calendar of Olivia Events. I have now put live the active calendar functionality on the site, and seeded it with possible calendar events. I will start planning our upcoming events – which require YOUR input on such things as, monthly sprints, special events that you want to do, and, our quarterly QSO parties.
3. Feedback form. This is a community website. Now, you can leave feedback; what would you like on the website. What should be different? What is not working? What is working? Please leave us feedback.

Come be a part of this conversational digital mode!

I have noticed a common theme regarding propagation on the 10 meter band. There is a wide perception that when the band goes quiet and worldwide DX dries up in June or July, the solar cycle must be diving such that the frequencies become useless. Having written the propagation column in CQ Amateur Radio magazine since 2001, I have done much research into this topic.

The reality is that while the 11 year solar cycle certainly dictates overall band health, the dramatic differences we see between seasons on 10 meters are driven by complex changes in the Earth’s atmospheric chemistry and magnetic field.

The F2 Layer and the Winter Anomaly

During the autumn and spring months, 10 meters comes alive for long range global communication. To understand why this changes with the seasons, we have to look at the F2 layer of the ionosphere.

Complex Propagation Modes

The seasonal shift in thermospheric winds and the resulting chemical changes in the F2 layer are the true drivers of what we experience on the radio. This phenomenon is known in physics as the Winter Anomaly.

• The Summer Fade: During the summer months, intense solar heating creates upwelling wind patterns in the thermosphere. These winds pull heavier molecular gases, specifically molecular nitrogen (N₂) and molecular oxygen (O₂), higher into the F2 region. This drastically increases the recombination rate of ions. The extra nitrogen acts like a sponge, rapidly absorbing the free electrons we need to reflect 28 MHz signals. Because the electron loss is so high, the overall electron density drops, and transoceanic skip fades away.

• The Winter Peak: The opposite happens during the cooler seasons. As we move away from summer, the thermospheric winds shift and the heavy nitrogen settles back down. The F2 layer becomes dominated by atomic oxygen (O). Without the nitrogen there to absorb the electrons, the recombination rate slows down significantly. This allows a highly dense F2 layer to build up, reaching peak electron densities around November and February. This atomic oxygen rich environment creates the perfect reflective environment for global 10 meter communication.

Summer’s Silver Lining: Sporadic E

When summer arrives and the F2 layer thins out, the band brings its own unique conditions with the prevalence of Sporadic E propagation.

These intense, highly localized clouds of ionization form in the lower E layer of the ionosphere. Sporadic E provides incredibly strong short skip contacts. These openings typically range from a few hundred to a couple of thousand miles, temporarily replacing the global propagation we enjoy during the spring and fall. Most folks scrolling through social media just want a basic understanding of why they are suddenly making loud contacts into neighboring states instead of talking across the ocean, and Sporadic E is the answer.

Global Reach: TEP and Chordal Hop

For North American operators looking to communicate with places like Brazil or Australia, different propagation mechanics come into play.

For communication down into South America, you are dipping into a fascinating phenomenon called Transequatorial Propagation (TEP). TEP is deeply tied to the F2 layer conditions, but it is heavily driven by the structure of the Earth’s magnetic field near the equator.

Around the geomagnetic equator, the magnetic field lines run exactly parallel to the surface of the Earth. This causes the free electrons in the F2 layer to be pushed outward and downward, creating two massive, highly dense bands of ionization located about 15 to 20 degrees north and south of the magnetic equator. We call this the equatorial anomaly, and it is the engine for TEP.

When you transmit from North America down toward Brazil, your 10 meter signal hits that northern dense band. Instead of reflecting back down to the ground or ocean, the signal deflects horizontally across the equator high in the ionosphere. It then hits the southern dense band and reflects down into deep South America. Because the signal stays entirely in the upper atmosphere and avoids a lossy bounce off the Earth’s surface in the middle, the signals can be incredibly strong and clear. TEP is most reliable during the spring and autumn equinoxes, usually peaking in the late afternoon and early evening hours.

Talking to Australia from North America is slightly different because the path does not cross the magnetic equator at the perfect right angle needed for textbook TEP. However, working Australia often relies on a very similar principle called chordal hop propagation. Instead of bouncing between the ionosphere and the ocean all the way across the Pacific, the signal enters the F2 layer and skips along the underside of the ionosphere for thousands of miles. It stays trapped high up where there is very little absorption, eventually dropping down to receivers in Australia with surprising signal strength.

Regional Variances

Radio wave propagation is never a one size fits all experience. Your location on Earth plays a massive role in what you hear on 10 meters.

• The Coasts versus the Midwest: If you live on the East Coast of the United States, your signals have a relatively unobstructed single hop path over the highly reflective saltwater of the Atlantic Ocean to reach Europe. The West Coast enjoys a similar geographic advantage when working Japan and the Pacific Rim. In the Midwest and central USA, your signals must often make an extra hop over land. Because land absorbs radio waves much more than saltwater does, central USA operators might find global F2 paths a bit more challenging. However, Midwest operators are perfectly positioned to work both coasts simultaneously when intense summer Sporadic E clouds form over the continent.

• Equatorial Advantage: Operators located closer to the equator experience less of the severe Winter Anomaly shift. Because they sit under the equatorial anomaly, they enjoy much more consistent F2 and TEP openings year round compared to mid-latitude stations.

• High Latitude Challenges: Operators in high northern or southern latitudes, such as Alaska or northern Europe, must contend with auroral absorption. During periods of high geomagnetic activity, the auroral oval expands and can severely degrade or completely absorb 10 meter signals, shutting down paths that cross the polar regions.

If 10 meters feels like a completely different band right now, do not blame the sunspot numbers. It is simply the natural seasonal shift in atmospheric chemistry and radio wave propagation at work. Enjoy the loud Sporadic E contacts while they last, and get ready for the worldwide skip to return when the seasons change.

Addendum: From the Southern Hemisphere

I was asked how this looks, from the land of Down Under.

Thank you for bringing the Southern Hemisphere perspective into the conversation! You hit the nail on the head regarding the inclination of the Earth’s axis, and it is the perfect starting point to explain why our experiences are mirrored.

Because the Earth is tilted on its axis by 23.5 degrees, the hemispheres take turns leaning toward the Sun as we orbit. Right now, the Northern Hemisphere is tilted toward the Sun, giving us summer. The Southern Hemisphere is tilted away, resulting in your winter. This means the ionospheric effects we experience are exactly reversed on the calendar.

When you mention that the high bands shut down after dark during your current winter, you are experiencing the harsh reality of wintertime solar geometry. During the winter months in the Southern Hemisphere, the Sun is much lower in the sky and the daylight hours are significantly shorter. While the Winter Anomaly we discussed earlier means your daytime F2 layer can actually become quite dense and highly supportive of 10 meter skip during the daylight hours, that ionization is entirely dependent on active sunlight. The moment the Sun sets at 5:30 PM, the source of ionization disappears. Because the winter night is so long, the F2 layer rapidly depletes, shutting the band down until the Sun rises again the next morning.

Conversely, when you head into your summer months of November and December, two major things happen. First, your daylight hours increase dramatically, which keeps the ionosphere charged much later into the evening and extends your operating time. Second, just as the Northern Hemisphere experiences a massive peak in Sporadic E propagation during our summer, the Southern Hemisphere experiences its own Sporadic E season during your summer. This provides those loud, reliable regional contacts. Finally, as you move into mid autumn around March and April, the Earth reaches the equinox. During the equinoxes, the Sun is directly over the equator, providing optimal and balanced F2 layer ionization for both hemispheres. This is why global, long haul propagation is at its absolute peak for everyone at the same time.

Regarding your question about East to West paths: yes, communication between Australia and South America is fundamentally very similar to the path between North America and Europe. Both are mid latitude transoceanic paths that rely on multi hop F2 propagation.

However, the Southern Hemisphere actually has a distinct geographic advantage for these contacts. Radio waves lose a small amount of energy every time they reflect off the Earth’s surface between ionospheric hops. Saltwater is an excellent, highly efficient reflector of radio waves, while landmasses absorb much more of the signal. Because the path between Australia and South America is almost entirely over the highly reflective saltwater of the Pacific Ocean, your multi hop signals suffer far less ground absorption compared to Northern Hemisphere paths that must often cross large expanses of land. This makes those Southern East to West paths incredibly efficient when the F2 layer is cooperating!

Welcome to the chaotic, thrilling world of the HF pileup. Whether you are the one calling CQ from a park in Nebraska or the one hunting a rare DX station, success relies on rhythm, frequency management, and a deep understanding of human behavior.

Here is a proper look at how a pileup appears on a modern display, followed by a complete guide on how to survive it.

A “pileup” on shortwave amateur radio frequencies. The main station is at the low frequency, and stays put. The hunters spread out, above, and call on a single frequency somewhere in the calling window of frequencies (I.e., up five to ten).

Over my decades of working Morse code (CW on amateur radio), I have learned a few critical things about how to navigate the chaotic, thrilling world of the HF pileup. When a rare station or a Parks On The Air (POTA) activator goes on the air, dozens or even hundreds of operators might try to make contact at the exact same time. Working a pileup is an art that takes time to master. Whether you are the one calling CQ from a park in Nebraska or the one hunting a rare DX station, success relies on rhythm, frequency management, and a deep understanding of human behavior.

One of the most important strategies is to determine the operating style of the DX station, specifically discerning how that operator scans the pileup for the next station to work. With modern waterfall displays, that process is MUCH easier. As an example, I worked the Temotu DXpedition (H40RH) that had just started a few hours prior to my attempt. I broke through with only five calls into the pileup, and it took me a mere 60 seconds to call and get an answer. Of course, I first listened and watched the waterfall for about five minutes to get a hang of the operating style of H40RH. This was on 10 Meters where 28.026 MHz was the DX frequency. We callers spread out five to 15 kHz UP in frequency from the DX station because we never want to cover up the DX station with our own signals. Even with a long carrier of intentional interference visible on the waterfall, the visual aid of the SDR made the catch possible. Temotu was a new country for my DXCC, so I am incredibly pleased to have made the contact!

When You Are the Hunted (The Activator)

A Guide To Survive The Pileup

When you are the station that everyone wants in their logbook, you are the conductor of the orchestra. If the pileup senses hesitation, chaos ensues. You must dictate the pace, for both CW and SSB operations.

Controlling the Pileup on CW

Establish a Predictable Rhythm: Your CQ, your exchange, and your QRZ should follow a strict pattern. Consistency allows hunters to time their calls perfectly. If you change your cadence, the pileup gets messy.

Run Split for Large Piles: If the pileup merges into a single continuous drone, go split immediately. You might send “UP 1” to tell callers to transmit one kilohertz above your listening frequency. This spreads the callers out. Send your “UP” frequently enough that the self-appointed pileup police do not take over your transmit frequency. I suggest sending “UP” after each successful logged contact (QSO).

Own the Partials: If you only pull “NW7” out of the noise, send “NW7?”. Do not send “QRZ?” immediately. Stick to that partial call until that specific station finishes the exchange. If they fade out, clearly send “QRZ?” to reset the pile.

Adjust Speed to Control Volume: A slight speed increase (bumping up 3 to 5 WPM) will naturally thin the pileup down to the more experienced operators. Dropping your speed will invite the newer operators back in.

Receiver Management: Back off your RF gain and use a wider filter than you might expect (around 400 to 500 Hz). A filter that is too narrow will cause you to miss the operators who are smartly calling slightly off-frequency.

Controlling the Pileup on SSB

Command with Your Voice: Speak clearly and maintain a steady, authoritative tone. Avoid shouting. Just like in CW, a predictable rhythm helps callers know exactly when to key their microphones.

Use Standard Phonetics: Stick strictly to the standard NATO phonetic alphabet (Alpha, Bravo, Charlie). Cute or custom phonetics confuse operators who do not speak English as their first language.

Acknowledge and Isolate: When multiple voices blur together, listen for the last phonetic letter you can understand. If you hear “Sierra,” say “The station ending in Sierra, go ahead.” Ignore everyone else until that station completes the contact.

My POTA / Portable HF station (a low-power, or, QRP, station).

When You Are the Hunter (The Chaser)

When you are trying to break through a massive wall of sound, raw output power is secondary to timing and sharp observation.

Breaking the Pileup on CW

Listen First, Key Second: Before touching the paddle, listen to three or four complete exchanges. If the activator is working split, figure out their pattern. Are they tuning from the bottom up? Top down? Find where they listened last, and place your transmit frequency just above it.

Use XIT (The Golden Rule): Never perfectly zero-beat the DX station if others are calling. To the activator, three zero-beat stations merge into a single tone. Use your Transmitter Incremental Tuning (XIT) to shift your transmit frequency by 30 to 50 Hz. This slight difference in pitch makes your signal pop out of the receiver passband.

Time the Tail-End: Wait for the massive wall of sound to begin fading, and send your call exactly as the main group finishes. A perfectly timed tail-end call lets your suffix ring out in the clear.

Send Once: When the DX sends “QRZ?”, send your callsign exactly once and listen. Sending your call multiple times just causes interference and slows down the entire operation.

Follow Instructions: If the DX sends “NW7?”, and that is not you, keep your hand off the key. Transmitting over the station they are trying to work only prolongs the pileup for everyone.

Breaking the Pileup on SSB

Study the Cadence: Just like with Morse code, listen to the activator to find the rhythm. Wait for the exact moment the activator stops speaking before you key up.

Drop Your Call and Wait: Say your full callsign once using standard phonetics, then unkey and listen. If you are tail-ending, you might just drop the last two letters of your callsign precisely as the noise floor drops.

Adjust Your Pitch: If you have equalization controls on your radio, boost the mid-to-high frequencies on your microphone audio. A slightly punchy and higher-pitched voice will cut through the bass-heavy rumble of a dozen other stations calling at once.

Working a pileup tests your patience and your ear. Whether you are tapping out Morse code or speaking into a microphone, the operator who listens more than they transmit almost always makes the contact first.

Propagation and the Pile-Up

As many of you know, I was the space weather and radio propagation columnist in CQ Amateur Radio Magazine from 2001 through its demise. I strongly advocate for all HF radio operators to understand the basics of radio wave propagation on shortwave frequencies. There are a lot of myths and frankly, horrific theories on how radio waves propagate.

Understanding how the ionosphere refracts radio waves is a crucial tactical advantage. The behavior of a pile-up changes dramatically based on the frequency band you choose and the current mood of our sun.

The Sun Dictates the Rules

The ionosphere is charged by solar radiation. When solar activity is high, higher frequencies become usable for long distances.

Solar Flux Index: The SFI is a great indicator of overall ionization. A higher SFI means better conditions for the higher HF bands. When the SFI climbs, bands like 15, 12, and 10 meters open up globally.

Geomagnetic Storms: Measured by the K-index, these storms can disrupt communications entirely. A high K-index often absorbs signals crossing the polar regions. This can suddenly mute a massive European pile-up for North American operators.

Fading: The ionosphere is always shifting. Signals will constantly rise and fall in strength, which is known as QSB. A smart chaser listens for the rhythm of this fade and throws their callsign into the pile-up exactly when the band peaks for their specific location.

How Bands Shape the Pile-Up

Every amateur radio band has its own personality. The pile-ups you encounter will reflect these differences perfectly.

10, 12, and 15 Meters: These high bands are daytime frequencies that thrive on high solar activity. When 10 meters opens up, signals can be astonishingly loud with very low atmospheric noise. Pile-ups here can ignite suddenly and stretch very wide across the frequency spectrum.

20 Meters: This is the traditional workhorse band for global communication. Pile-ups on 20 meters are massive, sustained, and densely packed. You will often compete with high-power stations and massive beam antennas on this frequency day or night.

40 and 80 Meters: These low bands come alive at night. They are heavily affected by atmospheric noise and static crashes. Breaking a pile-up here requires an exceptionally well-tuned ear and the ability to pull faint CW tones or muffled voices out of a very high noise floor.

The Skip Zone Effect

The propagation of radio waves.

One of the most confusing aspects of a pile-up for a new operator is the skip zone. Radio waves bounce off the ionosphere and return to earth far away, which means they skip right over the geographic areas in between. You might hear the DX station perfectly, but you might not hear the hundreds of other operators calling them because those callers are inside your skip zone. This phenomenon is exactly why you must rely on the DX station’s cadence rather than waiting to hear the pile-up clear.

While raw power is often cited as the key to breaking a pile-up, your antenna system plays a far more decisive role in your overall effectiveness. A directional antenna, like a Yagi or a hexbeam, not only focuses your transmitted energy directly toward the DX station but also actively rejects interfering signals from other directions. However, do not be discouraged if you are running a simple wire antenna. A well-placed dipole or end-fed half-wave can still break monumental pile-ups if you leverage good timing, exploit the skip zone, and listen closely to the DX operator. Ultimately, the best antenna in the world cannot compensate for poor operating habits.

Over to You

Working a pile-up is one of the most rewarding challenges in amateur radio. It tests your patience, refines your ear, and forces you to understand both the science of radio wave propagation and the psychology of your fellow operators. Every massive wall of sound is a puzzle waiting to be solved.

Now, I would love to hear from you. What was your most memorable pile-up experience? Do you have a specific tactic that consistently helps you break through the noise, or perhaps a frustrating moment that taught you a valuable lesson? Drop your stories and questions in the comments below, and let us keep the conversation going.

From my shack to yours, 73 de NW7US.

Senator Ted Cruz, in this pre-Memorial-Day message, thanks amateur (ham) radio volunteers who serve the public through emergency communications, readiness to meet public communications needs, and are ever-ready technical assets.

Senator Ted Cruz Highlights Amateur Radio Public Service (Memorial Weekend 2026)

Sen. Cruz highlights the role these amateur radio FCC-licensed volunteers have in providing essential communications when violent storms knock out communications in local and regional areas, when power is out, cellular communications limited or overwhelmed, and communications services are stressed beyond capacity. Senator Cruz notes that these ham radio operators step forward to provide first-response communications in many situations, and gives examples of such in recent years, such as the 2017 Hurricane Harvey emergency when the catastrophic flooding across Texas took so many lives, and ham radio was there providing critical emergency communications. This was again demonstrated in the horrible Camp Mystic floods. He emphasized that as the United States of America prepares for yet another Summer Season, ham radio volunteers are ready to step up and provide these essential amateur emergency communications services. His comments also reflect growing Congressional recognition of the value Amateur Radio Operators bring to communities across the country.

Senator Cruz is Chairman of the Senate Committee on Commerce, Science, and Transportation. His comments align with the ARRL’s ongoing efforts to strengthen and protect Amateur Radio’s role in emergency preparedness and public service communications. As a member of ARRL, I applaud the Senator’s acknowledgement of the service we amateur radio operators provide our communities.

This livestream recording is from September 1, 2024 – the NW7US Radio Communications Channel Livestream.  We do this livestream every Sunday at 21:15 UTC.  Here is the link to the livestream from this past Sunday:

The livestream list is here:

https://www.youtube.com/@nw7us/streams

I hope to see you in our livestream live chat, during the next session on Sunday, at 21:15 UTC.  See you there!

Curious about what you can hear on shortwave ham radio? This video is a brief survey of the diverse world of communications on the shortwave spectrum. Expand your radio horizons and enhance your emergency communication preparedness by tuning in to the world of shortwave ham radio.

If you’ve started delving into radio communications beyond local stations and channels, like VHF and UHF, you’re in for a treat. Shortwave radio opens up a whole new realm of signals to explore, including emergency communications vital during natural disasters.

[embedyt] https://www.youtube.com/watch?v=pIVesUzNP2U[/embedyt]

Shortwave radio covers a range of radio frequencies from 3 kHz to 30 MHz. This spectrum is home to a diverse array of radio signals that cater to various communication needs, making it a hub of activity and connectivity.

Within these high frequencies, you can tune in to a multitude of transmissions, from transoceanic air traffic control communications to the chatter of ships navigating the vast seas. Imagine hearing the voices of fishermen, much like those on your favorite reality TV shows about high-seas fishing adventures, along with military communications and the vibrant world of amateur radio enthusiasts.

One of the remarkable features of high-frequency (HF) radio is its ability to propagate signals over long distances, transcending line-of-sight limitations. This means that HF radio enables communication between different regions and even continents, fostering connectivity across vast distances.

During times of crisis and natural disasters, shortwave frequencies become invaluable for emergency communications. When local infrastructure falters or is disrupted, shortwave radio serves as a vital lifeline, facilitating critical two-way communications in and out of disaster-stricken areas.

Explore the fascinating realm of shortwave radio, where distant voices blend with essential information, bridging gaps and connecting communities in times of need. Uncover the power of HF radio to transcend boundaries and provide lifelines when they are needed most.

In this video, I give you a glimpse of the voice and data transmissions I pick up on my high-frequency amateur radio transceiver (in this video, an Icom IC-7000). In later videos, I will dive deeper into specific types of HF communications, such as aeronautical trans-oceanic signals.