Category: Tips

via HACKADAY: Antenna Tuning For GHz Frequencies

Antenna tuning at HF frequencies is something that radio amateurs learn as part of their licence exam, and then hone over their time operating. A few basic instruments and an LC network antenna tuner in a box are all that is required, and everything from a bit of wet string to ten thousand dollars worth […]

via HACKADAY: Using a Cheap Handheld Radio As A Morse Transceiver

Both grizzled hams and potential future amateur radio operators are well-served by the market these days. Powerful and capable UHF and VHF handheld transceivers can now be had for well under $100, something unimaginable as recently as 20 years ago. Of course, a major part of the amateur radio scene used to be Morse code. Not […]

via HACKADAY: Help For High-Frequency Hobbyists

Dead-bug circuit building is not a pretty affair, but hey, function over form. We usually make them because we don’t have a copper circuit board available or the duty of making one at home is not worth the efforts and chemical stains. [Robert Melville and Alaina G. Levine] bring to light a compromise for high-frequency prototypes which […]

via HACKADAY: Getting An RF Low-Pass Filter Right

If you are in any way connected with radio, you will have encountered the low pass filter as a means to remove unwanted harmonics from the output of your transmitters. It’s a network of capacitors and inductors usually referred to as a pi-network after the rough resemblance of the schematic to a capital Greek letter […]

via HACKADAY: Radio Antenna Mismatching: VSWR Explained

If you have ever operated any sort of transmitting equipment, you’ve probably heard about matching an antenna to the transmitter and using the right co-ax cable. Having everything match — for example, at 50 or 75 ohms — allows the most power to get to the antenna and out into the airwaves. Even for receiving […]

via HACKADAY: Filter your Pi and be a Responsible Pirate

At this point it’s pretty well-known that you can tack a long wire to the Raspberry Pi’s GPIO, install some software, and you’ve got yourself the worlds easiest pirate FM radio station. We say that it’s a “pirate” station because, despite being ridiculously easy to do, broadcasting on these frequencies without a license is illegal. […]

via HACKADAY: Putting a Poor Man’s Vector Analyzer Through Its Paces

If anything about electronics approaches the level of black magic, it’s antenna theory. Entire books dedicated to the subject often merely scratch the surface, and unless you’re a pro with all the expensive test gear needed to visualize what’s happening, the chances are pretty good that your antenna game is more practical than theoretical. Not that […]

via HACKADAY: An Introduction to Storm Detector Modules

Lightning storm detectors have been around for a surprisingly long time. The early designs consisted of a pair of metal bells and a pendulum. When there was a charge applied, for example by connecting one bell to the ground and the other to a lightning rod, the bells would ring when a lightning storm was close […]

FCC and OSHA Release Communications Tower Best Practices Guide

The FCC and OSHA have announced the release of a free publication, Communications Tower Best Practices Guide. While aimed more at those who tend commercial communication towers, the guide offers guidance applicable to the Amateur Radio community and contractors working on Amateur Radio antenna support structures. The FCC said the guide was a result of […]

via HACKADAY: Ham Radio Trips Circuit Breakers

Arc-fault circuit breakers are a boon for household electrical safety. The garden-variety home electrical fire is usually started by the heat coming from a faulty wire arcing over. But as any radio enthusiast knows, sparks also give off broadband radio noise. Arc-fault circuit interrupters (AFCI) are special circuit breakers that listen for this noise in […]