When I talk about doing VHF SOTA activations, people often wonder about what kind of contacts to expect. VHF propagation from a mountaintop can be surprisingly good, and the range of possible contacts runs from the routine to the remarkable. Having done a lot of these activations, I’ve noticed that VHF SOTA contacts tend to fall into three broad categories. Let’s take a look at each one.

Type 1: The Local Contact (20–30 Miles)

This is the most common type of VHF SOTA contact, and it’s what keeps most activations from getting skunked. A simple 2-meter FM handheld radio, a decent half-wave antenna, and a summit with good Height Above Average Terrain (HAAT) — that’s all you need to make contacts with stations in the surrounding towns and valleys.

The typical range for this category is roughly 20 to 30 miles, with some variation depending on terrain. From most Colorado summits, this covers small mountain towns, outlying suburbs, or rural homesteads with a radio operator and a 2m FM rig. These are the chasers who have 146.52 MHz programmed in, monitor for activity, and are happy to give you a quick contact. Often, I’ll catch mobile stations driving through the high country with their radio set on 2m simplex.

These contacts are the bread and butter of VHF SOTA. Mostly reliable, repeatable, and very useful for getting the four QSOs to get the activator points. Don’t underestimate them.

Type 2: The Extended Contact (30–150 Miles)

Now it starts to get interesting. This category requires a bit more effort — both from the activator and the chaser. We’re talking higher power, a better antenna, or both. On the summit end, a 3-element Yagi like the Arrow II provides about 6 dB of gain over a half-wave antenna, which makes a significant difference. It also helps to run more power than a handheld radio can, with 25 watts making a big difference. A home station using 50 watts with a quality high-mounted omnidirectional or beam antenna can significantly boost range on the chaser side.

These contacts are mostly still on 2m FM, although SSB and other modes can really help at these ranges. The contact might require pointing the Yagi in the right direction, asking the chaser to try a different antenna orientation, or just working a little harder to pull the signal out of the noise. These contacts are made at the margin, so every decibel of signal strength matters.

This category represents a real challenge, and that’s part of the appeal. When you complete a contact at 100 miles with some rough terrain in the way, it feels like an accomplishment. You earned that one.

Type 3: The Exceptional Contact (150+ Miles)

These are the contacts that make you stop what you’re doing and say “wow.” Distances beyond 150 miles on 2m FM are not routine — they happen when something special is going on. Three factors drive most of these exceptional contacts:

Favorable geography. Two high summits separated by a long distance can sometimes “see” each other in a way that lower-elevation stations cannot. In the Colorado high country, summit-to-summit contacts across large distances are possible when both operators are at altitude. The geometry just works out.

Favorable propagation. This is where it gets really fun. Sometimes enhancement occurs on the VHF bands, which means the signals become significantly stronger. Several elements contribute to this, though most link to tropospheric conditions. Tropospheric ducting can have a very strong effect, occurring when atmospheric conditions create a temperature inversion that takes VHF signals well beyond normal range. The ionosphere can also play a role, with Sporadic-E propagation opening up the 2-meter band unexpectedly, providing path distances of over 800 miles. This is rare on 2 meters and more common on the 6-meter band.

Modulation type. FM is a great mode for local and medium-distance contacts, but it is not the most efficient modulation for squeezing out long-distance QSOs. SSB and CW require significantly less signal strength to complete a contact compared to FM — a difference that can easily be 10 dB or more. That’s a huge advantage when signals are marginal. So when the conditions are favorable but not quite strong enough for FM, switching to SSB or CW can make the difference between completing the contact and just hearing a ghost signal in the noise. This is one of the reasons I’ve been enjoying the 2026 SOTA Challenge on 2m and 70cm CW/SSB — it pushes operators to explore what’s really possible on these bands.

My best 2m FM contact from a SOTA summit is 245 miles (Mount Scott (W5O/WI-002)  — that one was a keeper. My best 2m SSB contact was 372 miles, from Three Mile Mountain (W0C/SP-107) to N0LL in Kansas. Longer contacts are possible, but you have to be on the right summit at the right time, with the right chaser listening.

Which Type Is Most Common?

Type 1 is by far the most frequent, and Type 2 contacts are a regular occurrence for activators who show up with the right gear and a good summit. Type 3 contacts are not predictable, but they are not as rare as you might think.

The key takeaway is that VHF SOTA is not a one-size-fits-all experience. You can tune your station and operating strategy to optimize for any of these categories, or just show up with a handheld and see what happens. Either approach can work, and both are fun.

That’s the universal purpose of amateur radio, after all.

73 Bob K0NR

The post Three Types of VHF SOTA Contacts appeared first on The KØNR Radio Site.

Ham Radio License Class

Buena Vista, Colorado 

The Technician license is your gateway to the worldwide fun and excitement of Amateur Radio

• Earn your ham radio Technician class license
• Learn to operate on the ham bands, 10 meters and higher
• Learn to use the many VHF/UHF FM repeaters in Colorado
• Pass your FCC amateur radio license exam in class

Schedule:

Sat    May 9th    1-4 pm In-Person Kickoff Session
Wed  May 13     7-8 pm Online – Review session via Zoom
Wed  May 20     7-8 pm Online – Review session via Zoom
Wed  May 27     7-8 pm Online – Review session via Zoom
Sat    May 30     1–3:30 pm In-Person Review and Exam Session
(The exam session is open to everyone.)

Most of the course content will be delivered via the Ham Radio School online system, requiring about 20 hours of independent study by the student. Each chapter includes an eBook reading section, an instructional video, a review summary, a lesson quiz, and optional depth learning media. Our instructors will provide additional instruction and coaching during in-person and online sessions.

The in-person sessions will be at the Casa Del Rio Clubhouse in Buena Vista.
The fee for the class is $29.95.
Advance registration is required by May 1st.

Note: the FCC also charges a $35 license fee to issue your license, payable after you pass the exam
.
To register for the class or to get more information, contact:
Bob Witte KØNR    [email protected]

Sponsored by the Chaffee-Lake Amateur Radio Association

Click here to download Technician Class Flyer – May 2026

The post Technician Class – Buena Vista, CO appeared first on The KØNR Radio Site.

Unpacking the FAA's Boeing 787 Transponder Directive

As SARC Communicator editor I read a lot of blogs, club websites and other sources of amateur radio news. This one particularly caught my eye.

The source

https://www.paddleyourownkanoo.com/2026/03/14/ham-radio-enthusiasts-land-u-s-airlines-with-8-million-bill-to-fix-faulty-equipment-on-boeing-787s/ 

The ‘click-bait’ headline:

Ham Radio Enthusiasts Land US Airlines With 8 Million Bill To Fix Faulty Equipment On Boeing 787s

Ham radio enthusiasts could be partly responsible for landing U.S. airlines with an $8 million bill to fix faulty equipment on Boeing 787 Dreamliner airplanes after it was discovered that simple radio signals can knock out a faulty transponder on the popular widebody plane used by American, United, and Alaska Airlines.

The issue came to light after the Federal Aviation Administration (FAA) reported “multiple instances of loss of transponder for airplanes entering airspace in the presence of CW interference.”

CW interference refers to continuous-wave radio signals like Morse code, military transmitters, and even amateur ham radio signals, which could interfere with the transponder on some Boeing 787s...

When I saw this story it didn’t seem to add up. After all, Amateurs have been sending CW for a century and there has never been an allegation such as this. Although my own and other readers’ feedback has resulted in an adjustment of the original deceptive headline, the underlying story deserved  further investigation.

The actual facts

When the FAA warns of "CW interference," hams think of Morse code. Aviation engineers think of something far more dangerous—a silent, invisible wall of noise that can blind a Dreamliner to oncoming traffic.

In the world of amateur radio, "CW" is a beloved mode—the rhythmic cadence of Morse code cutting through the static, a testament to communication's simplest form. But when the Federal Aviation Administration (FAA) uses the same two-letter abbreviation in an airworthiness directive, it is describing something far more insidious and utterly unrelated to the operator in the shack.

For an avionics engineer, "Continuous Wave (CW) interference" refers to a pure, unmodulated, single-frequency carrier signal that has no business being where it is. It is a rogue tone, a sustained note of radio energy that can overwhelm sensitive aircraft receivers. And according to a new Notice of Proposed Rulemaking (NPRM) from the FAA, this type of interference is posing a direct threat to the Boeing 787 Dreamliner's ability to see and be seen by other aircraft.

The proposed directive, https://www.federalregister.gov/documents/2025/06/13/2025-10759/airworthiness-directives-the-boeing-company-airplanes which would affect 150 U.S.-registered 787-8, -9, and -10 aircraft, mandates a costly hardware replacement to fix a vulnerability that could, quite literally, render an aircraft invisible in busy airspace. But what exactly is this interference, and why is a simple hardware swap estimated to cost U.S. operators nearly $8 million?

The Problem: A Transponder That Won't Talk Back

At the heart of the issue is the 787's Integrated Surveillance System Processor Unit (ISSPU), a critical component that manages the aircraft's transponder. The transponder's job is to listen for interrogations from Air Traffic Control radar and other aircraft's Traffic Alert and Collision Avoidance Systems (TCAS) on 1030 MHz, and reply on 1090 MHz. Note that this is far from the usual HF frequencies that Amateurs normally operate at.

According to the FAA directive (Docket No. FAA-2025-0924), multiple reports have surfaced of 787s entering airspace with active "CW interference" and suffering a specific, dangerous failure: the transponder stops meeting its Minimum Operational Performance Standards (MOPS). Instead of correctly replying to at least 90% of interrogations, the unit becomes desensitized, failing to respond.

This is not a gradual degradation. It is an "unannunciated" loss, meaning the pilots receive no warning light, no aural alert, no indication that their aircraft is no longer replying to ground radar or TCAS inquiries. The first sign of trouble could be a gap in the sky where an airliner used to be, visible to everyone except the pilots of the aircraft that just went silent.

"CW" for the Layman: Not Morse Code, But a Wall of Noise

This is where clarification for the broader technical community is essential. For the amateur radio operator, "CW" (Continuous Wave) is synonymous with Morse code—a carrier wave that is turned on and off to form characters. It is intermittent, intentional, and communicative.

The "CW interference" cited by the FAA is something else entirely. In engineering terms, a "continuous wave" simply means a steady, unmodulated carrier signal. Think of it less as a conversation and more as a sustained, single-frequency tone—a pure, unbroken note of radio energy. If a pulsed radar signal is like a strobe light, CW interference is a laser pointer held steadily on a sensor, blinding it.

For a transponder receiver trying to pick out weak interrogation pulses from the sky, a powerful CW signal on or near its operating frequency (1030 or 1090 MHz) acts as a "jammer." It raises the noise floor, drowning out the very signals it needs to hear.

The Hunt for the Source: Who Is Generating This Noise?

The FAA directive is notably silent on the source of this interference, focusing instead on fixing the aircraft's vulnerability to it. So, who or what is generating these rogue continuous wave signals? The answer is complex and points to a crowded, modern radio spectrum. While the public document does not specify frequencies, the affected systems point squarely at the 1030/1090 MHz bands. Likely culprits for high-power CW interference in or near these frequencies include:

• Ground-Based Military and Civilian Radars: Some radar systems, particularly those used for long-range surveillance or specific military applications, can produce strong continuous or quasi-continuous output that generates harmonics or spurious emissions.
  
  
• High-Power Data Links: Terrestrial microwave data links, used for point-to-point communication by telecom companies and utilities, operate in frequency bands that can, with faulty equipment, generate out-of-band emissions that bleed into the aviation surveillance bands.
  
  
• The 5G Debate, Revisited: The recent spectrum battles between aviation and 5G carriers centered on the potential for signals from powerful ground-based transmitters to cause interference with radar altimeters. While that specific fight involved different frequencies (3.7-3.98 GHz), it perfectly illustrates the principle: a powerful, continuous transmission on a nearby frequency can overwhelm aircraft receivers if filtering and shielding are insufficient.

The $7.95 Million Fix

Because the sources of interference are myriad and largely outside an airframer's control, Boeing and the FAA have chosen to harden the aircraft itself. The proposed solution is not a software tweak, but a physical replacement of the vulnerable hardware.

While then issue is a worldwide problem, the directive would require US based operators to replace the left and right ISSPU units, swapping out current part numbers (822-2120-101 and -102) with a new, presumably better-shielded or more selective unit (part number 822-2120-113) . 

The FAA estimates the parts alone will cost $52,661 per aircraft. With labor, each of the 150 affected U.S. planes will incur a $53,001 expense, bringing the total for U.S. carriers to $7,950,150 .

This is a significant investment for a problem that many in the industry suspect is not going away. As the radio spectrum grows ever more congested with diverse signals, the threat of "CW interference"—in its true engineering sense—will only increase. For the pilots of the Dreamliner, this hardware upgrade can't come soon enough. For the amateur radio operator tuning up on 40 meters, rest assured: your key is not the culprit. The real threat is coming from elsewhere in the increasingly noisy radio spectrum we all share.

73,

~John VE7TI

Hello Radio Enthusiasts!

Inside this issue:

• Historical Deep Dives: From the electrical empire of Werner von Siemens to the high-stakes drama of the Alexanderson kidnapping, and a special event station commemoration of the Titanic disaster.
• Bench Projects: Learn how to make Homebrew PCBs with a 3D printer and copper tape, or peek at the elegant KD5ZZU Z-match tuner build.
• DX & Field Ops: Travel back to the 1994 Peter I Island DXpedition or get the latest on the North Fraser Club’s 925 MHz Balloon Project.
• Radio Secrets: Unlock the hidden "superpowers" of the Icom IC-7300, 7610 and 9700 and explore the "IPS Buffet" antenna mix-and-match review.

Download the Lower Resolution Issue - 6 Mb

Read it On-line as a Magazine

Please note that there are active links for additional content when viewed on your device.

~ John VE7TI, Editor

Contents for this issue: 

Big news — I’m proud to announce that the Second Edition of my book VHF, Summits, and More is now available. I’ve received tons of positive feedback on the first edition, published in 2019, and I decided it was time for an update. This new version is printed in color, which greatly enhances the photos and graphics.

This book is an easy-to-understand introduction to VHF/UHF ham radio with an emphasis on mountaintop VHF operation. I’ve enjoyed ham radio and writing about it ever since I received my first FCC license. Although I’ve used the ham bands from 160m to 10cm (10 GHz), I find the VHF and higher frequencies the most interesting. This is mainly because of the interplay between mountains, Height Above Average Terrain (HAAT), and VHF propagation. VHF has lots of spectrum, lots of modes, and lots of fun challenges.

For the second edition, I gave everything a fresh look. I updated every chapter and added 100 pages of new material. In Part I, the VHF tutorial section, I added new chapters to improve the treatment of basic VHF/UHF: Popular VHF/UHF Bands, Antennas, Coaxial Cables & Connectors, and WSJT-X Digital Modes. Part II covers topics that originated from my blog, often based on questions I hear from newer hams.  In Part III, which is focused on SOTA, I added several chapters on how to be successful doing VHF SOTA, and I added a few new trip reports. I also added some information on combined SOTA/POTA activations.

The book is available in two formats: a color print edition and a Kindle edition, both available from Amazon. The print version ships immediately; the Kindle version will follow shortly.

Order your copy now. Operators are standing by.
(Actually, just use the Amazon site.)

73 Bob K0NR

The post Second Edition of VHF, Summits, and More appeared first on The KØNR Radio Site.

The SOTA Management Team launched a special challenge for 2026: a distance-based scoring challenge using CW and SSB on the 2m and 70cm bands. The announcement is here on the SOTA reflector.

The basic idea is to encourage SOTA contacts using CW or SSB on these two bands. Because the scoring is based on distance, you need to enter the location of the other station. When chasing a summit, the location is already known by the SOTA database, but you need to have your location entered into the logging system. Summit-to-Summit contacts are easy to log because both locations are known. The hassle comes up when you are activating a summit and need the chaser’s location. An easy way to share location info is using the 6-character grid locator (e.g., DM78av at my house). Some chasers may know their 6-character locator but you may need to look it up. I usually ask the other operator if they are operating at home so I can look up the grid later. If they are away from home, I ask for enough information to be able to determine their grid.

W0C Activity

I wasn’t sure how many folks would pursue this challenge here in Colorado, but we are off to a good start. Here’s the current activator summary:

K0JJW and I have activated 5 times for the challenge, and have been pleasantly surprised with the number of chasers who get on, primarily using 2m SSB. It seems that some hams have 2m SSB capability, but don’t have many opportunities to use it. So they come out to play!

There are a few things to be aware of when operating these bands and modes:

Antenna Polarization

The first thing we ran into was the need to make sure both stations have the same antenna polarization. Common practice on VHF/UHF is to use vertical polarization for FM (and similar modes), but use horizontal polarization for CW/SSB and other weak-signal modes. The serious stations on CW/SSB will tend to have large Yagi antennas, horizontally polarized. But we soon found that many of the chasers at home were using vertical antennas on CW/SSB, because that’s what they have set up. No problem, on the summit we just flipped our handheld Yagi antenna to be vertical. The point is that antenna polarization should be taken into account, else you can experience a substantial signal loss.

Tuning in SSB

Another issue that surfaced is the need to do more precise tuning when using SSB. For FM, you can just dial in 146.52 or whatever and call it good. If there is a small frequency difference between stations, it does not matter. On SSB, a few hundred Hertz of frequency difference (which is common) causes the familiar “Donald Duck” effect, so you need to tune more carefully.

Most people know that the 2m SSB calling frequency is 144.200 MHz, so they start there. But if you hear an activator on 144.2001, you should tune to match their frequency when you call them. Don’t just sit on 144.200 and think “the other station is off frequency.”

Calling Frequency

Some sources list 144.100 or even 144.060 as the 2m CW calling frequency. These frequencies can be used, but common practice in Colorado is to just call CW or SSB on 144.200 MHz. That way, people monitoring the band for activity can find it more easily. Same thing with 432.100 MHz on the 70 cm band. Clearly, posting spots on SOTAwatch can really help with making CW & SSB contacts.

When activity picks up, the calling frequency can get busy. This is why most radios have a big knob on the front of the radio that allows you to tune up or down. Standard practice is to move up 5 or 10 kHz, as needed. If you are operating on the calling frequency for a long period of time, you should not be surprised if other people show up on frequency.  It works best if everyone cooperates, shares the frequency, and moves to adjacent frequencies when possible. This is similar to how 146.52 MHz can get busy on FM, so people shift to using 146.58 MHz to spread things out.

Quansheng UV-K5

Various people have hacked the Quansheng UV-K5, a dualband HT, to operate using CW and SSB. The modification consists of loading new firmware and, in some cases, doing a simple hardware modification. This video provides an overview of how this works. Many people are having fun modifying this HT, and it is an inexpensive way to get up and running on CW/SSB.

So come on out and give CW/SSB a try on VHF/UHF.

73 Bob K0NR

Getting Started on 2m SSB

The post SOTA Challenge: CW/SSB on 2m & 70cm appeared first on The KØNR Radio Site.

The Communicator First Issue of 2026

Happy New Year! This first issue of 2026 spans 110 pages and offers a comprehensive exploration of amateur radio. Readers will find a diverse mix of content, including technical projects, the latest operating news, and engaging historical perspectives relevant to the amateur radio community.

Historical and Informative Features

Readers will find historical profiles of notable figures in radio, this time including Edouard Branly, inventor of the coherer, and the fateful and communications-stricken flight of Amelia Earhart. The Silent Revolution: The future of RF is in light, is an overview of transceivers using light rather than wires, promising  less noise and terrific bandwidth. You will find tutorials on a variety of relevant subjects including HF digital modes such as FT8 and JS8Call, suggestions for contest logging software, and tips for successful portable operations.

Technical Articles

Several articles in this issue delve into practical projects and technical experimentation. Topics covered include encrypted communications in amateur radio, antenna construction and tuning, including the revolutionary Challenger+, low-power (QRP) operating strategies, free access to online software-defined radio receivers, and modifications to homebrew equipment. Additional articles address emergency communications preparedness, recent regulatory changes affecting Canadian amateurs, and reviews of new ham radio products and books.

Regular Sections

The issue includes our regular informative columnists, providing valuable information for operators.  They include feature propagation forecasts, updates on satellite and digital modes, reports on VHF/UHF activity, summaries of recent contests and on-air events, and even a ‘snow muffin’ recipe for Winter Field Day.

Feature Article: Embracing Versatility in Amateur Radio

An opinion piece reflected by the cover: “Are you an Amateur Radio chameleon?” (p. 102), employs the chameleon as a metaphor for versatility in the hobby. Drawing on the Senegalese proverb, “The chameleon changes colour to match the earth, the earth doesn’t change colour to match the chameleon,” the article gently critiques operators who specialize exclusively in one aspect of amateur radio—whether chasing DX on HF, focusing on VHF repeaters, contesting year-round, or limiting activity to digital modes like FT8.

While acknowledging that specialization can foster deep expertise, the article contends that remaining in a single niche may restrict personal growth and diminish the enjoyment of amateur radio. Instead, it celebrates those who adapt fluidly, moving between CW, SSB, digital modes, satellite work, QRP portable activations, microwave experimentation, public service events, and homebrewing. These “chameleons,” the article suggests, find greater fulfillment and contribute more broadly to the amateur radio community.

It concludes with an invitation for readers to share their own stories of adaptation and discovery by emailing [email protected].

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On behalf of SARC and SEPAR, we wish all of you a happy, healthy and prosperous new year.  

~ John VE7TI, Editor

Contents for this issue: