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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.

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:

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):

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:

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:

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.

Here’s a clear weatherfax decode at the Pacific Ocean near Stinson Beach, CA:

Here, picking up Selcal for HF comms with airliners over the Pacific:

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 interdigital filter for 70cm wavelength: