Few Things Are Cheaper Than This Antenna

As far as hobbies go, ham radio tends to be on the more expensive side. A dual-band mobile radio can easily run $600, and a high-end HF base station with the capability of more than 100 watts will …

Homebrew Sferics Receiver Lets You Tune Into Earth Music

It probably comes as little surprise that our planet is practically buzzing with radio waves. Most of it is of our own making, with cell phones, microwaves, WiFi, and broadcasts up and down the spe…

Making PCB Strip Filter Design Easy To Understand

We’ve always been fascinated by things that perform complex electronic functions merely by virtue of their shapes. Waveguides come to mind, but so do active elements like filters made from no…

Turning A Quansheng Handheld Into A Neat Desktop Transceiver

The Quansheng UV-K5 is a popular handheld radio. It’s useful out of the box, but also cherished for its modification potential. [OM0ET] purchased one of these capable VHF/UHF radios, but got …

A New Chinese Radio Breaks Cover, Is It Worth It?

Scanning the firehose of new electronic kits and modules coming from the usual Chinese suppliers can be a rewarding experience, as sometimes among the endless breakout boards comes an item that loo…

RF Detector Chip Helps Find Hidden Cameras And Bugs

It’s a staple of spy thriller movies, that the protagonist has some kind of electronic scanner with which he theatrically searches his hotel room to reveal the bad guys’ attempt to bug …

Silent Antenna Tuning

If you want to deliver the maximum power to a load — say from a transmitter to an antenna — then both the source and the load need to have the same impedance. In much of the radio commu…

Save A Packet, Use Cheap Co-Ax!

Anyone who works with radio transmitters will know all about matching and impedance, and also about the importance of selecting the best co-axial cable connecting transistor and antenna. But here&#…

Forget Flipper, How About Capybara?

One of the hacker toys to own over the last year has been the Flipper Zero, a universal wireless hacking tool which even caused a misplaced moral panic about car theft in Canada. A Flipper is cool …

Fundamentals Of FMCW Radar Help You Understand Your Car’s Point Of View

Pretty much every modern car has some driver assistance feature, such as lane departure and blind-spot warnings, or adaptive cruise control. They’re all pretty cool, and they all depend on th…

FM Transmitter Remotely Controlled Via ESP32

Imagine you’ve got an FM transmitter located some place. Wouldn’t it be mighty convenient if you could control that transmitter remotely? That way, you wouldn’t have to physically…

Tiny LoRa GPS Node Relies On ESP32

Sometimes you need to create a satellite navigation tracking device that communicates via a low-power mesh network. [Powerfeatherdev] was in just that situation, and they whipped up a particularly …

A Phone? A Ham Radio? Relax! It’s Both!

A lot of hams like to carry a VHF radio. Of course, nearly everyone wants to carry a phone. Now, thanks to the kv4p HT, you don’t have to carry both. The open-source device connects to your A…

What’s Your SWR? Are You Sure?

If you are involved in any sort of radio transmission, you probably have at least heard of SWR or standing wave ratio. Most transmitters can measure it these days and most ham radio operators have …

Braun TS2 Radio Turns 68, Gets Makeover

The Braun TS2 radio was a state-of-the art tube set in 1956. Today it still looks great, but unsurprisingly, the one that [Manuel Caldeier] has needed a little tender loving care. The table radio h…

A Universal RF Amplifier

If you need an amplifier, [Hans Rosenberg] has some advice. Don’t design your own; grab cheap and tiny RF amplifier modules and put them on a PCB that fits your needs. These are the grandchil…

Replacing Selenium Rectifiers

Old radios often had selenium rectifiers to convert AC to DC. The problem is that the old units, dating back to 1933, are prone to failure and to release dangerous chemicals like hydrogen selenide.…

Ferrites Versus Ethernet In The Ham Shack

For as useful as computers are in the modern ham shack, they also tend to be a strong source of unwanted radio frequency interference. Common wisdom says applying a few ferrite beads to things like…

Repairing A Hallicrafters S-120

[MIKROWAVE1] claims he’s not a radio repair guy, but he agreed to look at a malfunctioning Hallicrafters S-120 shortwave receiver. He lets us watch as he tries to get it in shape in the video…

How Sony Mastered The Transistor

When you think of Sony, you probably think of a technology company that’s been around forever. However, as [Asianometry] points out, it really formed in the tough years after World War II. Th…