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Scrounging for Science: How We Build Our Antenna Arsenal on a Shoestring

We have serious antenna plans. The good news is that executing them doesn’t necessarily demand a serious budget. Instead, it requires knowing where to look and the willingness to put in some elbow grease.

Over the past couple of years, we’ve been building a stash of dishes, poles, and towers that most research facilities would have to write a procurement justification, wait months for funding, and then more months for execution. Here’s how we bootstrap the whole thing.

MVPs find the right direction

We don’t wait until we have the “right” setup before we start learning. We stand something up, learn from it, and refine after proving that we’re heading in the right direction. Our gear stash exists to make these cycles low-cost and fast.

Case in point: our current antenna field includes everything from a fan dipole strung over a canyon to a full-wave 630m loop — the seed of what will eventually become our Giga Loop, a receive antenna covering over 15 acres of the property.

None of that happened by waiting for the perfect conditions or equipment. We build the minimum viable experiments, learn from them, and iterate from there. Let’s take a closer look at our gear stash and the story behind the pieces.

Free Ku-band dishes from neighbors

Rural neighbors upgrading to Starlink have one problem: what to do with the old HughesNet and Viasat hardware bolted to their roof or fence post? We solve that problem for them by taking the dish off their hands. Everyone wins.

The result is a growing collection of consumer satellite dishes, roughly 18 to 30 inches in diameter, from DIRECTV, Dish Network, HughesNet, Viasat, etc.

Applying Ku-band dishes to RF research

The smallest dishes (e.g., DIRECTV and Dish Network) are the least useful for us. With some exceptions, such as possible amateur use at 24GHz, the Ku- and Ka-band dishes aren’t effective parabolic reflectors. They don’t gather enough signal because they’re too small relative to the wavelengths we work with, and smaller dishes collect less signal anyway.

Why keep them in our mix? They weigh less and are physically easier to work with. They catch less wind and are sturdier. These characteristics make them prime material for testing new motorized azimuth/elevation tracking systems: we’ll know the target satellites’ positions and auto-calibrate our tracking systems by finding the maximum signal strength for a satellite.

Moreover, we can use universal feed mounts to attach X-band feeders to these Ka-band dishes. That doesn’t seem to make sense, as the gain will be low and the signal will be out of focus. However, that “weak, wide, and fuzzy” field of view will be beneficial when we take numerous repeated “quick whole sky” surveys, as smaller dishes can move faster and scan wider swaths of sky per streak.

Of course, there’s no free lunch. We pay the price in lower signal strength and less precision. However, the many wide-field-of-view low-res scans can give us insights that fewer, narrower beam-width high-res scans cannot. It’s like using a wide-angle lens to take high-ISO pictures to identify where to look before strapping on a long lens and taking a long-exposure photo for precision.

The hunt for giant C-band dishes

Before small dishes took over in the mid-90s, rural America ran on large C-band parabolic dishes — typically 8 to 12 feet across. Most of them are still out there, sitting in fields and backyards, inherited by people who have no idea what to do with them and no desire to move them.

We scored a couple of these from folks in our community and one from Facebook Marketplace. Even the transfer station attendant knows to keep a lookout for us.

Applying giant C-band dishes to RF research

A 10-foot dish is 20 times the longest wavelength, big enough to provide meaningful gain for S-band, such as tracking space missions (e.g., Artemis 2 operated on the 2.2 GHz band). Assuming a high surface precision, these dishes can work up to any microwave frequency we want to play with. In fact, the higher the frequency, the higher the gain and the narrower the bandwidth.

However, pivoting that behemoth around isn’t a zippy affair. It’s also hard to do that with high precision. As such, we use the smallest dishes to meet a study’s requirements, not the 10-footer for everything.

And yes, we’ll try moonbounce on the 13cm, 9cm, 5cm, and 3cm bands.

Our telephone pole pipeline

Old utility poles are a rural constant: properties accumulate them over decades, and nobody wants the hassle of removal or hiring someone to truck them out. We put the word out that we’re looking for phone poles, and people just say, “Come get ‘em!” We score pieces up to 27 feet tall — essentially a free antenna mast, already seasoned by years of outdoor service.

These are the workhorses behind our Beverage antenna wire support: quick to deploy, cheap to source, and sturdy enough for long wire runs across our 20-acre site. When an antenna design calls for spans stretching 1,500 feet across the site, not having to buy masts makes a real difference to the budget.

Beverage antennas don’t need to be high off the ground; just elevated enough so that roaming cattle and other animals don’t ruin them (fun fact: we’re in an open range area!) The stubby poles are great for this purpose and can also provide a sturdy base for temporary small masts. For example, we can strap a 30-foot mast to these poles, as long as the winds are under 70 mph.

Will drive 4 hours for antenna towers

Telephone poles do the job, but antenna towers do it better. Yet, any ham operator who’s priced out new tower sections knows they’re a serious line item. For example, we recently scored a 67-footer that’s equivalent to the Tashjian WT-67 with an $8,677 price tag in its basic form, excluding transportation costs.

The good news is that used towers are a different story if you know where to look. Some people might have inherited them when they purchased a property. Some have to part with them because HOAs really don’t like them.

We scout Facebook Marketplace for these towers across rural communities and make the long drive to get them, once a 4-hour one-way with a 14-foot trailer.

These sections are modular, allowing us to dial in the exact height required. They’re also lighter and easier to maneuver on-site thanks to built-in mounting provisions. Of course, not all of them are in ready-to-deploy shape. Some repair work and elbow grease are required before we can put them into service.

Using antenna towers in our RF research

Conventionally, these towers are used to support rigid antennas. Most commercial installations have fixed antennas, while most amateurs want rotatable beams. We’ll do neither of those and use the towers primarily for supporting wire antennas that must be high off the ground to work well.

We plan to use our two tallest towers (54 and 67 feet), which are easy to crank up and down, as agile bases for long wire antenna experiments. Others, like the fixed 35-foot Rohn 25, will be used as elevating structures to augment the effects of the canyons in our fixed installations.

Results, not red tapes

Building this gear stash isn’t glamorous. It involves Facebook treasure hunts, trailer runs on steep dirt roads, and a lot of quality time with ratchet straps. But the upfront effort means that when an experiment calls for a 10-foot dish or a 40-foot mast, we’re not waiting on a purchase order — we’re already setting it up.

April 17, 2026
A Tower-Free 472kHz Inverted L Antenna for the 630m Band
There’s a certain humbling quality to working at 472kHz. You pull up the math, realize a proper half-wave vertical would need to be over 300 meters tall, and then you have a moment. A long moment.

Then, you get creative.

Let’s dive into how we approached building a transmit antenna for the 630m band at our Kern County site. This post explains why we selected the inverted L configuration, how we leveraged the landscape to avoid a massive tower, what our simulations predict, and what we hope to learn once the antenna is operational.

472kHz is a pain in the neck but worth the trouble

At 472kHz, your antenna wants to be enormous. A half wavelength is around 315 meters — taller than the Eiffel Tower. So a “proper” full-size vertical is off the table for us mere mortals outside the broadcast engineering world.

But setting up the antenna isn’t just for the game.

The 630m band is relatively uncrowded and, compared to HF bands, surprisingly understudied, partly due to antenna size limitations and partly due to site availability.

Most existing research on LF and MF propagation comes from flat, low-elevation sites or coastal plains, where soil conductivity is high, well-characterized, and relatively uniform. Our site is none of those. At 3,500 feet above sea level in the Sierra foothills of Kern County, it sits in a natural RF-quiet bowl surrounded by mountains. It features rocky terrain, a known aquifer below, and almost no local interference.

That combination of elevation, geology, and low-noise environment is rare. As a result, we generate propagation data that doesn’t exist anywhere else. But still, why go through the trouble?

At 630m, signal behavior is shaped simultaneously by soil conductivity, terrain geometry, and ionospheric D-layer conditions. We provide a clean baseline to untangle those contributions. Our unique site condition takes this antenna beyond a radio project to a data source for researchers who currently have to work around gaps in available datasets:
- Geologists and hydrologists can access empirical data on how 630m ground-wave signals interact with rocky, mountainous terrain and aquifer-influenced soil when modeling subsurface features. The data is thin in this discipline.
- Atmospheric and space-weather scientists studying D-layer behavior can gain long-term observations from RF-quiet sites. Most existing datasets come from coastal or urban-adjacent receivers with noisy baselines.
- Earthquake researchers investigating pre-seismic electromagnetic patterns can access data from a geologically active site. We’re in a seismically active country with interesting geology and a noise floor that lets subtle signals surface.
We’ll return to the impact on scientists and researchers shortly. First, let’s look at how the antenna itself can be built — affordably and without years of permitting hurdles.

Leveraging our site’s unique characteristics with an inverted L antenna

An inverted L antenna is exactly what’s on the tin: a wire that goes up vertically, then bends horizontally. The vertical section does most of the radiating work. The horizontal top section primarily loads the antenna electrically, helping it reach resonance at a physically manageable length.

For our target frequency, we aim for a quarter wavelength, about 150 meters of wire. But how do we gain meaningful vertical height without a self-supporting tower? Solving this challenge is where our canyon earns its keep.

We plan to run a support wire from rim to rim across the canyon, with poles on both sides. The antenna’s vertical section rises from the feedpoint at ground level up to that support wire, where it makes a 90-degree turn and runs horizontally to one side, while the other end provides mechanical tension. The setup gives us usable height, sourced from existing terrain, and nature does the heavy lifting.

Site map

Here’s the full geometry breakdown:
- North-south section: ~100m along the map, ~35m effective height
- East-west section: ~40m along the map, ~25m height
- Total wire length: ~150m (~quarter wavelength at 472kHz)
Antenna layout across the canyon

Another unique aspect of this build is that the antenna’s vertical section rises partly over solid terrain on the canyon rim, and partly suspended in open air over the canyon. While it’s possible to model an antenna over poor rocky terrain or in free space, current tools can’t cleanly model one that transitions between the two mid-wire.

We’re in greenfield territory.

A conventional approach to achieving what we’ve outlined would involve a 30-meter self-supporting tower, a concrete foundation, permit applications, and a significant budget. Such hurdles are exactly why we created ClearSkyRF to help accelerate RF research and use amateur radio as a tool to generate scientific, geologic, and atmospheric insights.

This is also how we challenge the “this is how things are done” mentality. We’re not here to build the definitive, fully optimized, write-it-up-for-IEEE antenna farm. We create something good enough to generate real-world data, learn from it fast, and decide where to dig deeper.

The unsung hero: a ground system that makes the difference

At low frequencies, a poor ground system will hurt your antenna efficiency more than almost any other design choice. The feedpoint of an inverted L antenna sits close to the ground, and its return currents flow through the ground. However, if that path is lossy, the power that should be radiating turns into heat instead.

Again, nature provides a solution: a clay soil layer with an aquifer underneath.

Our ground system consists of multiple grounding rods driven into the site’s clay soil section, combined with a radial wire network that spreads out from the feedpoint. We will build in the ability to connect or disconnect those radials independently, allowing us to run the antenna with and without them to directly measure the efficiency difference. Such a before-and-after comparison is more useful than any simulation, giving us real-world numbers for the actual soil condition.

For the baseline calculations, we use conservative soil parameters: a dielectric constant of around 13 and a conductivity of 0.0002 mS/m, typical for a rocky, mountainous terrain. In practice, we expect better numbers. The aquifer beneath our site will likely improve ground conductivity in ways that are difficult to predict precisely without direct measurement — understanding the difference is part of the experiment.

Simulation result with a pleasant surprise

Before stringing a single wire, we modeled the antenna to check resonance, impedance, and radiation pattern. The numbers came back encouraging. At 472kHz, the model shows:
- Impedance: R ≈ 6.8Ω, jX ≈ 3.5Ω — low resistance, as expected for a short antenna, which means a matching network will be needed between the feedpoint and standard 50Ω coax
- SWR curve: Clean resonance across the 630m band
- Gain: ~1.1 dBi — spectacular for this class of antenna
Simulation plots — SWR curve, impedance vs. frequency, radiation pattern

The radiation pattern also demonstrates a notable null of around 6dB of attenuation to the west. Follow that bearing, and you end up pointed at the antenna farm on Mount Wilson, north of Los Angeles. The dense cluster of high-power broadcast transmitters would otherwise contribute significant interference to any receiver in Southern California.

Mount Wilson tower farm

The null isn’t pure luck. The orientation and directionality of the horizontal top section determine how the pattern tilts and which direction the null goes. Run it north-to-south, and the null points one way. Flip it south-to-north, and the pattern flips with it.

We chose our orientation deliberately to put that null on Mount Wilson. In effect, we have some directional control over a 472kHz transmit antenna. As far as we know, no one else on the planet operates an electrically steerable antenna on the 630m band.

What this antenna will tell us

Once in the air, this antenna will be a transmit reference for experiments that are difficult to run anywhere else. These include:

Propagation characterization

By transmitting WSPR beacons on the 630m band and tracking their reception, we can build a propagation map based on our site’s characteristics, including elevation, terrain shielding, and soil, and compare the results against model predictions.

Ground-wave vs. sky-wave separation

At 472kHz, both propagation modes are active, and they behave differently over distance and time of day. Our low noise floor and known antenna geometry will allow us to distinguish them more cleanly than at a noisier site.

Soil and subsurface sensing

Ground-wave signal strength over distance is a proxy for soil conductivity. The gap between the assumed soil parameters and our measured antenna efficiency provides insights into what’s happening in the ground beneath us, including potential aquifer influence. The data will show us both ends of that equation, while the radial experiment will further sharpen the picture.

Atmospheric and space weather correlation

The 630m band is sensitive to D-layer ionospheric conditions, which respond to solar activity, geomagnetic storms, and some terrestrial weather patterns. Long-term continuous monitoring from a quiet, elevated site generates a unique baseline that makes anomalies visible and attributable.

Seismic monitoring potential

Pre-seismic EM anomalies in the LF and MF bands have been reported in the literature for decades, but the evidence remains contested — partly because clean, continuous datasets from geologically active, RF-quiet locations are rare. We’re in a position to contribute to that record in a way most sites can’t.

None of these is guaranteed. Some may turn out to be dead ends. That’s the point — the minimum viable experiment exists to explore possibilities without betting an entire facility on one hypothesis. And the inverted L antenna doesn’t have to do this alone.

Building a multi-antenna experiment

The inverted L is a transmit antenna. But what makes it genuinely useful as a research tool is how we pair it with other antennas.

We’re designing a regimen that alternates transmission and reception across other antenna systems on our site. The combination opens up comparisons that a single antenna can’t provide on its own.

On the receive side, we have two complementary tools. The Giga Loop is a full-wave 630m loop that will eventually encircle over 15 acres of the property. It picks up signals from all directions with a large effective aperture. Its size makes it unusually sensitive at these frequencies, and running it alongside the inverted L antenna provides a direct comparison between a compact transmit antenna and a large receive loop on the same signals, at the same site, at the same time.

We also have the receive-only, directional Beverage antennas aiming at nine regions across the globe — domestic targets split across the West Coast, Midwest, and East Coast, plus international bearings toward Europe, Asia, and beyond. Beverages are low to the ground and highly directional, making them poor transmitters but excellent weak-signal receivers. They enable us to pull a signal from a specific direction while rejecting noise from others.

With these antennas working together, we can run multiple experiments with different perspectives simultaneously. For example, we may transmit on the inverted L antenna and receive on the Giga Loop and Beverages. We may also switch orientations, connect or disconnect ground radials, and log the variations.

Questions and answers will emerge: Does the signal received on a Beverage aimed northeast match what the propagation model predicts for that bearing? Does the Giga Loop see the same fading events as a directional Beverage, or different ones? When an anomaly shows up (e.g., atmospheric, seismic, or otherwise), does it appear across all three antenna systems, or only some?

No single antenna answers those questions, but our combination can.

But talk is cheap…

The theory is sound, and the simulation looks promising. The physical build is the next step: getting the support wire across the canyon, rigging the poles on both sides, and laying out the radial ground system. After that comes the matching network, as the ~7Ω feedpoint impedance needs a transformer to interface with standard 50Ω coax and the transmitter.

The initial tests will be WSPR beacons at low power. We’ll watch for spots, compare against the modeled radiation pattern, and measure efficiency with and without the ground radials connected. Then, we’ll publish what we find — the good, the surprising, and the awkward.

We’re not a university lab with a five-year funding cycle and a crane on call. The goal isn’t the perfect antenna. We will build the first good-enough antenna that starts generating data no one else is collecting. We provide the testing ground to help ambitious projects get off the ground without waiting years.

Stay tuned to see what we find out.
April 4, 2026
Beverage Antennas for Low-Band, Weak-Signal Research
To set the stage for future data collection and research opportunities, one of our inaugural projects was a series of Beverage antennas for long-wave, low-frequency bands (receive only).

Why Beverage antennas?

They’re easy and quick to execute. Since they don’t need to be high off the ground, we can mount them on a few 4x4s or telephone poles to gather meaningful data with an MVP setup, instead of spending months on infrastructure.

This post explores how we meet the various criteria for building a Beverage antenna and the specifics of our setup for long-wave, low-frequency bands.

Criteria for building a receive antenna for low-band, weak-signal research

Beverage antennas can receive signals from one or both ends. Weak signal research requires the ability to “aim” where the antennas receive the signal from. Additionally, we need the ability to attenuate/reject undesirable signals to increase the signal-to-noise ratio and, therefore, the ability to decode signals.

A successful Beverage antenna setup for low-band weak signal research goes beyond theories and calculations. Simply finding a site that can accommodate the length of the antenna is quite a challenge. Here are the top considerations and how our 20-acre property enables us to set up four antennas aiming at nine general regions across the globe.
- Technical requirements. Beam pattern design is a tradeoff between desirable technical characteristics (gain, directivity, lobe beam width). The wider the beam, the more you receive, but you also collect more undesirable signals (i.e., noise). While a narrower beam provides more focus, you’d need more antennas to cover all orientations.
- Lobe overlaps. You need a sizable property to achieve the ability to select where the signals come from and orient the antennas so that the lobes overlap just enough to minimize gaps.
- Financial costs. Cables are costly, while low-frequency means a long wavelength. A Beverage antenna must be at least half a wavelength long. The setup shown above requires 3,000’+ of connecting cables.
- Physical support for cables. Long cables sag. Our property offers several opportunities where the long antennas intersect at a 45-degree angle, allowing us to set up physical support at a practical cost.
- Real estate. Studying long-wavelength signals means you need acreage to accommodate long antennas. The blue line in the above diagram is 1,500’ long, stretching across the entire property. The site has a fairly “square” shape, allowing us to set up long-wavelength antennas in multiple directions.
- Terrain and mounting opportunities. The property must provide opportunities for mounting antennas so the intersection angles work with the antenna field design. In most cases, researchers must invest time and resources in foundations for anchoring antenna poles or towers. Our property, on the other hand, features rock formations perfect for anchoring antenna poles quickly and cost-effectively.
- Soil characteristics. Beverage antennas work best on rocky/sandy/electrically lossy soil, and our property has just the right type of soil for such research.
The practical implementation of our Beverage antenna series

First, we identify the wavelength to focus our study on.

472 kHz is the sweet spot. The physical dimension still allows for practical implementation on the property. Meanwhile, there are enough people studying it so that we’re not doing this work in a vacuum.

Then, we determine where we pull signals from by segmenting the world and focusing on areas worth isolating, i.e., people are transmitting signals. We started with domestic bearings, segmenting the U.S. into three regions: the West Coast, the Midwest, and the East Coast.

Next, we consider interference sources to inform the antenna’s directionality. Los Angeles is about 100-150 miles south of our site. If we set up an N-S antenna, we’d catch a lot of noise from the city. Instead, we leave a gap between the 340-degree and 30-degree antennas to minimize undesirable signals.

For weak signal research, we want to focus on international targets because domestic ones (while we still want reasonable coverage) are “too easy.” So, we identify regions we can reach on an international map:

Besides places we can reasonably reach (proven in a few preliminary test runs), we map out “boundary challenges” — stretch targets that don’t have many practical examples of communications on the two lowest bands covering such vast distances.

So, why does this approach make sense?

This setup uses fairly traditional and common communication methods and systems to hone weak signal operations. Once we refine the details and achieve a world-class sensitivity level, we have the groundwork for future research. For example, we can use the data and insights for different applications, such as geological phenomena recording, soil studies, and more.

If you have a research project that can use this Beverage antenna setup, we’d love to hear from you! Get in touch to explore collaboration opportunities.
February 16, 2026
Antennas in Various Stages of Operation on Our Site

As of January 2026, we have several antenna setups that are in various stages of operation or repair on our site. Here’s an overview.

The start of the Giga Loop

A full-wave 630m loop at varying heights ranging from 10 to 100ft off the ground. In practice, the feedpoint impedance is way off from the simulations, but that’s okay. As of Spring 2025, it is partially dismantled for construction work on the property, but even with half the wire coiled up, it still picks up stations from across the world.

It starts off here and circles a part of the property:

Perhaps because of the capacitive loading and its proximity to ground, it resonates much lower than I anticipated/simulated, and the feedpoint impedance is miles off from where it should be.

We use the learnings from this experiment to build our Giga Loop, which will cover over 15 acres.

A fan diapole

This antenna hung about 75 feet over a canyon on our property. The feedline was balanced at the 600-ohm line. This antenna is currently down, mostly because the feedline was not practical due to the distance to the shack — it constantly got tangled up. I will need to either build a remote tuner or maybe find a source of 450-ohm ladder line at a reasonable price, as I might need about a quarter mile.

I love the simplicity of a fan dipole, also strung over the canyon. This is fed by a current balun and RG-6 Cable TV coax at 75 ohms, because it is cheap for long runs and has no significant loss at HF for resonant antenna use.

Vertical Antennas

I’m not exactly a “vertical enthusiast” (they’re noisy), but this contraption is quite useful for transmitting. It has four radiating elements and eight elevated radials. Fed with one 75-ohms coax for all 6 bands.

Another dual bander: vertical for 80, inverted L for 160. All wire. Strung over a canyon with six radials going east-west and the “L” going north-south. The radiation pattern is almost omnidirectional.

Sometimes, temporary antennas stay up a little longer than planned. Almost a year ago, I planted a few 2x4s into the ground as a makeshift “mast” to get something in the air for 6m, 2m, 20m, and 40m. All are fed with RG-6, as I had a couple of 500ft spools lying around.

The 2-meter antenna is a monopole with radials bent to match the 75-ohm impedance of the cable. The physical insulator is a spark plug. The 6-meter antenna on the right is a vertical dipole. No balun was used, even though it is a balanced antenna. It was supposed to be up for a day, and I was out of balun materials.

These two inverted Vs share a 4×2 “mast” (pole? stick? contraption? eyesore!) Both coaxials are RG-6. Balun is 1:1.

February 16, 2026
A Back-to-Basics WSPR Beacon Setup (It Reached Tasmania!)

For me, Amateur Radio is about designing and building equipment, experimenting, and learning. I have done so for/on almost every amateur frequency, from 630m to X-band. Rag chews or contesting do not speak to me much. My antennas are mostly omnidirectional, simple, and resonant, including a full-wavelength loop on 472 kHz. However, reality forces me to settle for a 630m loop that is just a fraction of a wavelength above ground.

I’ve been working on this back-to-basics WSPR beacon since June, 2025.

If you pick up my WSPR beacon on 80m, this is what the signal came from: a homebrew built-from-first-principles design. The oscillator is a 74HC00 NAND gate. The NTSC color burst crystal was modified with a Sharpie to oscillate on 3570.1 kHz.

A second NAND gate is used to gate the oscillator signal, producing CW. I sign off my WSPR transmissions with my callsign in CW.

The microcontroller is an ATTiny88 in some Arduino form factor. I never developed an interest in object-oriented programming, so I usually wipe the bootloader and write my own code in assembler or sometimes a higher-level language.

Time comes from a DS3121 RTC. Drift is deep sub-second per day, but it needs occasional tuning to keep the drift under a second.

WSPR modulation is created by driving a low-pass-filtered PWM signal into a reverse-biased red LED, which is used as a varactor in the crystal circuit. A few pF is enough to pull the crystal over the ~4.5Hz range dictated by the WSPR protocol.

The PA is a 74AC240 with two times 4 drivers driven differentially. I measured the differential output impedance to be about 17 ohms, so I use a 5:1 balanced-to-balanced impedance transformer (a balbal?), giving about 90 ohms to the antenna port. LPF is a 5th-order differential Butterworth LC filter. I know I should not have used an SMA connector, but I was originally not planning on a differential drive.

Power is a single Li-Ion cell, with no power conversion. This causes about 20Hz of drift over the supply range. The 2Ah cell powers the beacon through the night.

The transmission line to the antenna is about 30m / 100ft of Cat-5 network cable.

The antenna is an inverted V with the apex at 30ft / 10m, but unfortunately, 100mW will not boil off any clouds.

One night of operation on one battery charge yields the following. I’m rather pleased with that for 100mW of power into an inverted V at one-eighth of a wavelength high.

It was even spotted in Tasmania — with 100 mW, on 80m! On a couple of occasions, it got to Alaska, which I thought was pretty good, but Exceter in Tasmania is 12,839km. Almost 130,000 km per watt, with an NVIS antenna made from garbage wire (24 Ga CCA, so aluminum).

If you pick up my WSPR beacon on 20m, the story is somewhat different. This is a more “traditional” approach, using an Si5351A CMOS clock generator programmed around the 20m WSPR frequencies on both sides of 14.097100 MHz.

The rest is mostly the same; the LVDS 3.3V p-p signal is boosted to 5V with a 74HC gate, and the PA is a 74AC240, here driven at 6V.

When loaded between 15 and 20 ohms differentially, Pout is around 300mW, and PA dissipation is about a Watt before the output filter. The transmission line (CAT-5) is over 20 ohms resistively alone. The ERP is about 100mW into a resonant inverted V about 7 meters up. 20m is an easy band, so down under and “up over” at VY0ERC showed up within hours.

February 16, 2026
Creative Antenna Experiments Series: An SDR Setup for Backpacking

Our mission at ClearSkyRF is to provide a low-threshold experimental environment that unleashes new forms of creativity and scientific insight.

Using what’s at hand and making the most of your surroundings is critical to gaining quick insights without the high price tag associated with formal experimentation.

In this series, I share documentation from my past experiments — hopefully to spark ideas and conversations.

My spouse and I go backpacking once in a while. On a week-long trip through Wyoming, I packed the lightest possible SDR setup: an Android phone, a battery bank, small solar panels, an RTL-SDR, an upconverter, a balun, and some wire.

February 16, 2026
Creative Antenna Experiments Series: A Homemade Antenna Launcher

Our mission at ClearSkyRF is to provide a low-threshold experimental environment that unleashes new forms of creativity and scientific insight.

Using what’s at hand and making the most of your surroundings is critical to gaining quick insights without the high price tag associated with formal experimentation.

In this series, I share documentation from my past experiments — hopefully to spark ideas and conversations.

I often joke that this antenna stuff is a sport — especially when you need to put a wire high up onto trees.

Here’s an antenna launcher I made to get wire antennas into trees. It’s as sketchy as it looks, but highly predictable as it follows the laws of ballistics. Software controls the mixture of butane (Bosch injector) and air (air mattress pump), and shoots a soda bottle containing exactly 200ml of water. I could hit a tree branch 100ft up without fail.

Here’s a video of how it works in practice:

February 16, 2026
Creative Antenna Experiments Series: Building PCBs and Homebrew CNC

Our mission at ClearSkyRF is to provide a low-threshold experimental environment that unleashes new forms of creativity and scientific insight.

Using what’s at hand and making the most of your surroundings is critical to gaining quick insights without the high price tag associated with formal experimentation.

In this series, I share documentation from my past experiments — hopefully to spark ideas and conversations.

I like to design and build my own PCBs, sometimes as artisanal as possible. Here I am drilling one on a homebrew CNC made from wood and drawer slides (it’s handy, even if it’s not for surviving a zombie apocalypse):

The toner transfer method is time-honored, fast, and reliable.

This clip shows how I generally do it:

This is one of my “standard RF experimenter’s designs:

Sometimes I have my designs fabricated, of course. Especially above a couple of GHz:

SSOP-focused for playing with PLL chips:

Of course, not everything needs a PCB. I’ve made plenty of things on protoboards. Here’s a remote HF antenna switch for selecting beverages:

Here’s a DTMF decoder for a transcontinental remote access project (it worked flawlessly):

February 16, 2026
Creative Antenna Experiments Series: An 80m HF Beacon (CW and RTTY only)

Our mission at ClearSkyRF is to provide a low-threshold experimental environment that unleashes new forms of creativity and scientific insight.

Using what’s at hand and making the most of your surroundings is critical to gaining quick insights without the high price tag associated with formal experimentation.

In this series, I share documentation from my past experiments — hopefully to spark ideas and conversations.

Here’s an 80m HF beacon (CW and RTTY only) I made a while back:

Mitsubishi RD16HHF power transistors are my favorite for 6m and below. I tried with BD13x before, assuming 80m is so low in frequency that I might get away with it, but the results were just not good enough.

10dB down on the third harmonic without output filters isn’t bad:

February 16, 2026
Creative Antenna Experiments Series: An Opportunistic Vertical Antenna Using Railroad Tracks

Our mission at ClearSkyRF is to provide a low-threshold experimental environment that unleashes new forms of creativity and scientific insight.

Using what’s at hand and making the most of your surroundings is critical to gaining quick insights without the high price tag associated with formal experimentation.

In this series, I share documentation from my past experiments — hopefully to spark ideas and conversations.

Radio gear can be cumbersome, and gathering signals takes time. Setting up some quick experiments while traveling is often an interesting challenge.

Once, I had a series of meetings in Silicon Valley. We stayed in Santa Cruz, CA, and I found a spot with tall trees and railroad tracks, which provided perfect grounding. A vertical antenna is a no-brainer.

Here’s a way to get a 160m signal… I could only get this level of signal when running solely on laptop battery power, as any other piece of electronics produced too much noise on low bands.

It was also good for picking up the 60kHz VLF signal from WWVB:

February 16, 2026