There are plenty of hobbies around with huge price tags, and ham radio can certainly be one of them. Experienced hams might have radios that cost thousands of dollars, with huge, steerable antennas on masts that can be similarly priced. But there’s also a side to the hobby that throws all of this out of the window in favor of the simplest, lowest-cost radios and antennas that still can get the job done. Software-defined radio (SDR) turned this practice up to 11 as well, and this radio module uses almost nothing more than a microcontroller to get on the air.
The design uses the capabilities of the Raspberry Pi Pico to handle almost all of the radio’s capabilities. The RF oscillator is driven by one of the Pico’s programmable I/O (PIO) pins, which takes some load off of the processor. For AM and SSB, where amplitude needs to be controlled as well, a PWM signal is generated on another PIO which is then mixed with the RF oscillator using an analog multiplexer. The design also includes a microphone with a preamplifier which can be fed into a third PIO; alternatively it can receive audio from a computer via the USB interface. More processor resources are needed when generating phase-modulated signals like RF, but the Pico is still quite capable of doing all of these tasks without jitter larger than a clock cycle.
These switch kits are the output from an effort to keep myself busy while on COVID-19 lockdown. I originally intended to just teach myself how to program and interface with various types of microcontrollers (PIC, Arduino, etc.). So, I bought several of the newbie training kits off of eBay and went to town. After exhausting all the built-in exercises, I went looking for a project where I could use my new-found knowledge.
I had owned an Ameritron RCS-12 remote antenna switch for many years and had always wondered how they selected antennas by simply pushing a momentary pushbutton switch. After opening up the controller, my suspicions were confirmed that a microcontroller was at the heart of the design. So, I decided to attempt to recreate the unit’s features that I used most as a breadboard project.
Open parts for Ham Radio station
My source for Coax and Coax jumpers
The Antenna Farm is a distributor of two way radios, antennas, coax cables, coax connectors and related accessories. Many police and fire departments, EMS companies, public service organizations as well as the average consumer rely on us for a wide variety of high quality two-way radio products from industry leading brands.
Having been in business for over 20 years, The Antenna Farm has developed a wealth of expertise and experience in the two-way radio industry and is always happy to help our customers choose the best equipment for their particular needs and budgets.
Since 1988, we have been developing and manufacturing high-frequency components and devices for well-known industrial companies, research institutions and ham radio operators. High Frequency components for industry and research.
Australia's Largest range of Electronic Kits and Components for the Radio Experimenter
ANTENNA MAKING SUPPLIES/ DOG BONE INSULATORS AND STAINLESS ANTENNA WIRE CLIPS. End-fed half wave antennas EHHW
Archives of Ham Radio Magazine
A variety of new and used vintage and hard to find radio components for home brew projects including:
List of Broadcast, Fixed Broadcast, Studio-Transmitter Links (Feeders), Remote Pickup & Relay stations 25 - 87.5 MHz.
Figure R3 of 47 CFR 73.190 of the Commission’s Rules contains a map of the estimated effective ground conductivity in the United States. This data is used to predict the propagation of AM signals across the United States. A higher ground conductivity indicates better AM propagation characteristics. The map shows that the ground conductivity in the U.S. ranges between 0.5 and 30 millimhos (or millisiemens) per meter. The conductivity of seawater is 5,000 millimhos per meter, resulting in the best propagation of AM signals.
Figure R3 of 47 CFR 73.190 of the Commission’s Rules contains a map of the estimated effective ground conductivity in the United States. This data is used to predict the propagation of AM signals across the United States. A higher ground conductivity indicates better AM propagation characteristics. The map shows that the ground conductivity in the U.S. ranges between 0.5 and 30 millimhos (or millisiemens) per meter. The conductivity of seawater is 5,000 millimhos per meter, resulting in the best propagation of AM signals.
I make no claims for technical accuracy, good design, or necessarily even originality for the contents of these pages. Rather, I am a simple enthusiast attempting to convey my love and enjoyment of radio, electronics, and computing and perhaps to inspire YOU to build something too. The following pages document projects that I have built over a period of 30 years. Wherever applicable I have named sources and references.
Radio Hobbyist’s Designbook or RHdb (for short) was designed to guide you into design of
electronics apparatus that relates to radio. It assumes you know something about electronics
but you can skip Chapters which cover familiar subjects. Mathematics needed in design is down
to simple algebra and trigonometry. Topics cover the frequency spectrum of DC through VHF.
You must supply the brainpower. But RHdb can be your main reference, a guidance toreaching
your personal hobby goal. RHdb is written in a sort of Reader’s Digest format: Short and
to-the-point, covering things simply with a minimum of words. Grouping is in 5 sections as
givenbelow with a synopsis of Chapters
The original AirBoss was made by my Grandfather (KR4LO) in order to help ham radio operators deploy their antennas over tall trees. I, the Grandson, have taken over the production of the AirBoss. Olah Technologies LLC will continue to bring you the AirBoss and other innovations.
WORLDWIDE DX CLUB "Top News", compiled by Wolfgang Bueschel
You have probably heard people talk about ionosphere virtual height. What is it and why is it important for HF propagation?
Slow Scan Television (SSTV) images transmitted from the International Space Station and other ARISS supported satellites
This site will be the focal point for some of the best SSTV images received during Oct 2008 and beyond. Images will be downlinked by ISS on 145.800 MHz. To view some of the received images transmitted from the ISS
The General Radio Experimenter was a revolutionary magazine, that offered students, engineers and hobbyists invaluable content and applications for electronics.
Organized by year for easier browsing, following are links to every General Radio Experimenter, over 500 issues, that span the 1920's through the 1970's for viewing and download.
Radio-Electronics was an American electronics magazine that was published under various titles from 1929 to 2003. Hugo Gernsback, sometimes called The Father of Science Fiction, started it as Radio-Craft in July 1929. The title was changed to Radio-Electronics in October 1948 and again to Electronics Now in July 1992. In January 2000 it was merged with Gernsback's Popular Electronics to become Poptronics. Gernsback Publications ceased operations in December 2002
The Universal Radio Hacker (URH) is a complete suite for wireless protocol investigation with native support for many common Software Defined Radios.
Motorized 10-80 Meter Adjustable Dipole
DRM for mediumwave has been tested and documented for two decades