A Few of My Favorite Things: Amateur Radio



Hackaday has a significant number of writers on its staff who also hold amateur radio licenses. We’re hardware people at heart, so we love our homebrew radios, and we’re never happier than when we’re working at high frequencies.

Amateur radio is a multi-faceted hobby, there are such it’s incredibly interesting about it. So it’s a shame that as a community we sometimes get mired in negativity when debating thoroughness. So today, let’s talk about some of my favorite things about the amateur radio hobby. Hope you find them interesting and entertaining, and share your own favorite things in the comments below.

Minimal Genre Homebrew Radios

This book was where it all started for me.

The protests and disaster preparedness can leave me cold, but there is magic in the minima when it comes to radio. My introduction to electronics in the 1970s was in the simplest form of radios, when my dad bought me a copy of George Dobbs Make a transistor radio, and showed me how to build a crystal set. That so few pieces could form a working radio that pulls a signal out of the air and into my headphones without needing batteries was magical enough to make me addicted to a 9 year old.

Upgrading to a regenerative germanium transistor receiver set me on the path that led me to college to a degree in electronics engineering, and ultimately to write here at Hackaday. There is in a very literal sense a whole world to unlock using radios made with relatively small BOMs, and although I have occasionally fumed about the tendency of these designs to get a bit stuck in the – mud there is no reason that minimalist radios cannot evolve over time. The fact that a quadrature front-end for an SDR sound card could be made from little more than a bunch of 74-series chips is a particularly appealing example.

Scrapping TVs as a Gateway to RF Design

One UHF construction kit in each bucket
One UHF construction kit in each bucket

I got my amateur radio license back in the dawn of time, when the UK Department for Trade and Industry only distributed two types of documents. There was the class A or class B license, with the difference that for the first one had to pass a Morse test but have access to the HF bands while for the second one had no Morse but was limited to 144MHz and more. So the old men could talk quietly about The War for 80 meters, and the 2-meter fanfare was a lively place.

I had no interest in Morse code, so I had a Class B license, and since radio construction was my passion at the time, I set out to build for the VHF and UHF bands. I didn’t have an adult’s budget so my component supply was limited to what I could get from consumer electronics, which meant many 1970s PAL TVs and the occasional model video recorder. prior. There were many VHF compatible inductors and transistors, and each TV tuner and VCR modulator had a set of UHF compatible transistors, so the 2 meter and 70cm bands were within my reach.

There is one sore spot among all of these memories, and it is a deep grounding of RF design techniques. RF is considered a dark art by many engineers, and while there are certainly design cues at these frequencies that blend into the complex, it remains true that once you get a feel for the basics, it is still true. is something that is easily possible to master. When you learn about stripline circuits by assembling them from copper and tin wire, you learn a lot about shielding, impedances, routing, and interactions between neighboring circuits. Sure, it’s easy to make mistakes, but in this world with a soldering iron it’s just as easy to try out alternative designs until performance improves. So many of the top UHF and RF circuits are now wrapped in silicon that the type of transistor circuits I was bothering with have become rather obsolete and your UHF work is much more likely to be on a PCB than a piece of iron. white, but the same principles apply. I miss those BF180 RF amplifier transistors from 1970s televisions.

SDR as a digital playground

The age of the RF homebrew handyman may be near, at least the way I started it. No one on the cutting edge of radio is likely to play with discrete transistor circuitry in the 2020s, unless maybe they’re working with extremely exotic devices in millimeter wavelengths. useful radio experience on a computer but that’s it. No more homebrew, no more DIY.

It would have taken a long time to build and obtain as physical components.
It would have taken a long time to build and obtain as physical components.

You might agree with the previous paragraph, but SDRs provide me with another of my favorite things about radio, which is that by using GNU Radio, I now have a processing playground. general purpose digital signal. Coupled with a cheap RTL-SDR dongle, it gives me the ability to play with all of the same building blocks that I used to use with my soldering iron and many others, at speed. lightning bolt on my computer. I can build a radio in no time, and change its settings at will! The best part is, it’s not just limited to radio. The GNU radio operates at any frequency that can be digitized by its input device, and if it is an audio card, it can also work with audio. Most readers of last April’s Fool’s Day probably spotted my fake golden USB cable a mile away, but perhaps fewer understood that GNU Radio’s simple audio analyzer was quite real. It was inspired by a Supercon talk by Mike Ossmann and Kate Temkin, and if you haven’t seen that talk I suggest you give it a watch.

So yes, there are plenty of amateur radio stations that interest other radio amateurs but which have never interested me, and there are still some aspects of the hobby that can be rightly criticized. But amateur radio is indeed a very large church, and above you saw some of the things that still interest me. Now it’s your turn, tell us in the comments: which radios do it for you?

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