Nicholas Italiano in Preparation

High Frequency Radio Operations

Wyoming Survival’s 2-Day HF Masterclass

In This Article

Understanding the Waves
Solar Maximum & the Ionosphere
Band Breakdown & NVIS
Setting Up for Success
Stealth, Security & the Dark Side of HF
Final Thoughts
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Tony Peel doesn’t look like your typical radio operator. No uniform, no government badge, just a guy who knows his stuff. He’s the founder of Wyoming Survival, a former survival instructor, a blacksmith, and a licensed General HAM operator. That last bit matters because, in the world of radio communications, a General HAM license is your gateway to operating on high-frequency (HF) bands — a skillset that stretches far beyond the limits of the popular Baofeng handheld radios many preppers stash in their bug-out bags.

On day one of the HF Operations class, Peel wasted no time breaking down the fundamentals, starting with a question: What is HF? Short for “high frequency,” it refers to the spectrum of radio frequencies between 3 and 30 MHz. Unlike UHF and VHF radios, which require line-of-sight to communicate and often struggle through dense vegetation, HF can reach across continents. With the right setup, it’s entirely possible to connect with someone 5,000 miles away. That’s not just theoretical, it’s a reality for pilots, NGOs, military units, and even banks that use HF for secure, long-distance communication.

Most handheld radios, like the Baofeng, operate on UHF and VHF bands. If you’ve used one before, you’ve probably noticed that getting any kind of range without a clear line of sight is a struggle. Trees, hills, and buildings devour those signals, and if you’re lucky, you might hit one mile without special gear. With a jungle antenna, a specialty setup for denser environments, you can push it to two miles, but that’s still a far cry from the kind of distance HF is capable of. Peel laid it out bluntly, HF isn’t just different; it’s a whole new ballgame.

HF Radio setups come in many flavors — from base stations that require more permanent fixed positions, to some rigs as small as a deck of cards. Each with their own strengths and weaknesses.

Understanding the Waves

When you key the mic on an HF rig, it sends out a frequency that propagates as a wave. Imagine ripples spreading out in water. The space between the peaks of those ripples is the wavelength. On higher frequencies, the peaks are closer together, and on lower frequencies, they spread out. This matters because antennas are built to match those wavelengths, specifically, half-wavelength antennas for optimal transmission.

Peel dove into how HF propagates and explained the difference between ground wave versus sky wave. While ground wave travels along the Earth’s surface, sky wave bounces off the ionosphere, an atmospheric layer charged by the sun. This is where HF shines. Its signal can reflect off the sky and hit far-flung locations, sometimes across entire continents. That’s the kind of range that makes HF indispensable when infrastructure becomes inoperable.

A student deciphers a transmission utilizing a one-time pad key.

Solar Maximum & the Ionosphere

The ionosphere is key to HF operations. It’s made up of four main layers: D, E, F1, and F2. During the day, all four layers are active, but at night only D and F2 remain. That shift impacts how far your signal travels and which frequencies work best. Peel also explained the role of the solar maximum, an 11-year cycle where sunspots pepper the surface of the sun, charging up the ionosphere and boosting radio propagation. During this period, HF signals reach farther and with more consistency. But it’s a double-edged sword. Solar flares, those massive bursts of energy from the sun, can disrupt communications entirely, almost like someone flipping the off switch.

Despite the damage of this coax cable, it is still more than capable of sending and receiving HF transmissions.

The 80- to 40-meter bands are where things get really interesting. These frequencies are the most stable and reliable, especially once the solar maximum wanes. Peel pointed out that while the 40m band typically gets you around 700 miles during the day, it can stretch to 1,500 to 2,000 miles at night. For anyone relying on HF for critical communication, understanding these cycles is important survival knowledge.

Tony Peel illustrates how radio frequencies can be bounced off the ionosphere to achieve incredibly far transmission distances.

Band Breakdown & NVIS

Peel also covered the different HF bands:

80m Band: Ideal for nighttime communication
40m Band: Great for daytime local communication and nighttime long-distance (DX) communication
20m Band: The go-to for long-distance (DX) communication

He then explained Near Vertical Incident Skywave (NVIS), a method that uses steep takeoff angles to bounce signals almost straight up and back down, perfect for regional communication. NVIS works on the 40m band during the day and the 80m band at night. It requires a horizontal antenna placed low to the ground, sometimes directly on it. Inverted V antennas also work for this setup. To find the right frequency for NVIS, Peel recommended using prop.kc2g.com.

Peel also reminded the class that HF isn’t your cell phone; there’s no trillion-dollar infrastructure guaranteeing you’ll get through. It’s just you, your radio, and the atmosphere.

By using a device called an antenna analyzer, the antenna can be shortened or lengthened, fine tuning it for whichever band is being used for transmission.

Setting Up for Success

Before setting up our own NVIS system and testing it out, we went over the gear required to make HF work:

Transceiver: Japanese-made models are recommended. A 100W transceiver with MARS modification can operate during solar minimums. Built-in tuners and sound card interfaces are a must.
Antenna: Di-pole antennas are the standard. Multi-band options exist, but a simple dipole is often the most effective. Common configurations include inverted V, upside-down L, and NVIS.
Coax Cable: Less than 100 feet of 50-ohm cable is ideal.
Tuner: Essential for matching your antenna to the radio
Power Source: 12-volt systems, solar with a charge controller, or battery with an inverter
Grounding: Critical for stability and safety
Lightning Arrestor: Installs between antenna and coax to prevent damage
SWR Meter: Used to measure signal efficiency

Midway through day one, the class tuned into the Noontime Net, checking in with call signs and running tests. Digital versus SSB communication was also covered. Digital is more reliable, offering encrypted messaging, low power consumption, and even inbox-style messaging. Peel demonstrated WinLink for sending texts and weather reports, VARAC for mesh networking, and FLDIGI for real-time chat and Morse code translation.

Insulated wire is being measured to the appropriate antenna length.

The day wrapped up with a hands-on exercise, setting up radios, deploying antennas, and sending digital messages across the airwaves. The class got a taste of SOTA (Summits on the Air) and POTA (Parks on the Air), two international amateur radio programs designed to push the limits of field-based HF communication.

Stealth, Security & the Dark Side of HF

The second day opened with a discussion on tactical communications planning. For the uninitiated, this means creating a step-by-step guide for how a team or group will communicate during operations, emergencies, or grid-down events. It outlines which frequencies to use, when to switch channels, call signs, fallback plans, and how to keep messages clear but secure. Without one, teams risk confusion, missed messages, and potentially dangerous delays.

HF has what Peel called a “dark side.” Anyone listening on the same band can hear your transmission. That makes security a real concern, especially if you’re passing sensitive information. Encryption might seem like the obvious answer, but it’s illegal on amateur bands in most countries, including the United States. That’s because the amateur radio service is meant to be open and non-commercial. Only licensed entities, like businesses or government agencies, can legally encrypt their transmissions.

Even if encryption were legal, there’s another hurdle: the key. Encryption only works if everyone has the same key, and if that key is compromised, your messages might as well be public.

One workaround is the one-time pad — an old-school cryptographic method invented in the early 1900s and still considered unbreakable if used correctly. It involves pairing your message with a random key that is used only once and then destroyed. Each letter or character in the message is shifted by a corresponding character in the key. Without that exact key, deciphering the message is virtually impossible. But the catch remains, both sender and receiver must have matching pads ahead of time.

Peel also mentioned PTE (Paranoid Text Encryption), a software tool that can encrypt text files on a separate device before they’re sent over radio. While still operating in the legal gray area on HAM bands, it’s a tool worth knowing for emergency use.

Many metallic wires can be used as an antenna, including this scrap electrical wire taped to the frayed end of a coax cable.

From a hardware perspective, antenna placement was another key topic. An HF antenna should be oriented broadside to the direction you want to transmit or receive. This positioning aligns with how radio waves radiate, strongest perpendicular to the wire, weakest off the ends. The class also covered the Wilderness Protocol, a practice where radio operators periodically monitor emergency frequencies (especially at the top of each hour) to give lost or stranded individuals a chance to reach help. It’s a grassroots system, not a formal emergency service, but can be a lifesaver when cell towers are far away.
Another critical point, without specialized gear, you can’t determine where an HF signal is coming from. That’s where direction-finding equipment comes in. Peel introduced tools like the KrakenSDR, a multi-antenna software-defined radio that triangulates signals based on time-difference of arrival. There are also simpler setups using rotating directional antennas or signal-strength meters, but these require skill, space, and patience.

Then came the build. We were shown how almost any metal wire — speaker wire, house wire, even barbed wire — can be used to make a functioning antenna. The class assembled a half-wave antenna, which is cut to half the wavelength of the frequency you’re using. This length allows the antenna to resonate efficiently, sending out a stronger, clearer signal. Power conservation was also emphasized. Transmitting at high power makes you easier to locate via direction-finding. Running at the lowest effective wattage helps you stay off the radar. And as for antenna insulators? Peel debunked the myth that you need ceramic or fancy gear. Dry paracord works just fine.

The day ended with a practical test: sending and receiving messages between two groups on opposite sides of a mountain in Wyoming. One group used a traditional HF radio and antenna. The other used what Peel called “disaster wire,” which in our case was scraps of electric fence strung up with a frayed coax cable. Using NVIS, the groups successfully transmitted voice and digital messages over a 15-mile stretch of terrain. No cell service. No towers. Just raw capability.

Final Thoughts

Although the idea of operating an HF radio can seem intimidating, with a knowledgeable instructor like Peel, the process turns out to be pretty straightforward. It’s also reassuring to know that the ability to communicate is only a few steps away. This class brought together a wide range of students — from licensed radio operators looking to fine-tune their setups to complete newcomers like myself. Every one of us walked away with new skills and a better understanding of how radios can be used effectively.