It isn’t easy being a ham operator inside city limits. Restrictions in where you can place antennas, power requirements which can disrupt communications and entertainment systems, and just the sheer amount of electrical noise to contend with can take the fun out of the hobby.
Proficiency in sending and receiving Morse code — while no longer required for licensure — is the best way to experience traditional ham radio. Today, there are dozens of freely accessible websites and free or inexpensive apps for Android and iOS tablets and phones that provide sophisticated and efficient Morse code training. However, one of my favorites is the Morserino-32: a feature-packed microcontroller-based send and receive trainer, available from Willi Kraml OE1WKL for $99.
The Smith Chart turns the complex mathematics of transmission lines into circles and arcs that unlock the mysteries of SWR, stubs, matching networks, and a whole lot more. It’s an amazing tool that brings the arcane math of transmission lines to visual life so you can understand them.
Even though CW is no longer a required component of amateur radio license tests, it’s still a practical and fun skill to learn. Plus, these days, there are many different learning aids readily available. All you need is the discipline to spend 10-20 minutes/day practicing and you’ll be sending and receiving CW before you know it.
Most frequency counters can tolerate only low levels of RF at their input, but here’s a way to safely measure the frequency of an RF signal of up to 200 watts with your existing frequency counter.
If the antennas that hams use can focus a signal, then they need to be able to focus it in the desired direction. The thing that hams use to point their antennas — large and small — is called a rotator. There is a wide range of rotators, just like with antennas. We’ll cover some of the most common types and give you an idea of how they work. After all, your ham radio success turns on them!
There are a lot of technologies that got a start on some ham’s wireless workbench. Ham radio almost demands tinkering and inventing. Some creations get no farther than a one-time project, while others become the basis for companies and industries.
Rarely has there been as much interest in a high frequency radio as that shown to the Microbitx. Low power enthusiasts — better known as QRP operators as well as ham radio hobbyists — have rushed to place their order for this exciting and challenging new transceiver kit. Challenging in that it’s had a problematic chip “on its shoulders.”
Filters are one of the most important and widely-used circuits in all of radio at any frequency. Understanding how they are specified and used will make you a better electronics designer, whether you build your own or simply buy them from a vendor.
Magnetic loop antennas are becoming popular today because they can be very efficient for their size, do not need radials (even though most designs are vertically polarized), have useful takeoff angles, and can be easily rotated to peak or null a signal. Here’s how I designed a convenient setup for myself.