Watch out, Baofeng; there’s a new kid on the cheap handy talkie market, and judging by this hardware and firmware upgrade to the Quansheng UV-K5, the radio’s hackability is going to keep amateur radio operators busy for quite a while. Like the ubiquitous Baofeng line of cheap transceivers, the Quansheng UV-K5 is designed to be a dual-band portable for hams to use on the 2-meter VHF and 70-centimeter UHF bands. While certainly a useful capability, these bands are usually quite range-limited, and generally require fixed repeaters to cover a decent geographic area. For long-range comms you want ..read more

[Dan Robinson] picked up a shortwave receiver known as the “stressless” receiver kit. We aren’t sure if the stress is from building a more complicated kit or operating a more complicated receiver. Either way, it is an attractive kit that looks easy to build. Presumably to reduce stress, the VFO and receiver boards are already built, so assembly is just a few hours connecting large components and boards. As kits go, this is a fairly simple one. We were surprised to read that the supplier says you can’t upgrade the firmware. We, of course, wonder if that’s true. For technical specs, the receive ..read more

Like many people [Dan Greenall] spent a lot of time in the 1970s listening to shortwave radio. While you often think of that as a hobby involving listening to broadcast stations, some people like to listen to other communications such as airliners, ships, military, and even spy stations. These days, if you hear a strange signal you are probably only one internet search away from identifying what it is. But back then, you had to depend on word-of-mouth or magazines to figure things like that out. [Dan] found a recording of a mysterious military-like signal he made in 1971 on 14.85 MHz. He deci ..read more

Before the Internet, if you wanted to hear news from around the world, you probably bought a shortwave receiver. In the golden age of world band radio, there was a great deal of high-quality programming on the shortwave bands and a large variety of consumer radios with shortwave bands. For example, the Sony CRF-160 that [M Caldeira] is restoring dates from the late 1960s or early 1970s and would have been a cool radio in its day. It retailed for about $250 in 1972, which sounds reasonable, but — don’t forget — in 1972 that would have been a 10% downpayment on a new car or enough to buy a Big ..read more

For all their talk of cooperation and shared interests, the nations of the world put an awful lot of effort into spying on each other. All this espionage is an open secret, of course, but some of their activities are so mysterious that no one will confirm or deny that they’re doing it. We’re talking about numbers stations, the super secret shortwave radio stations that broadcast seemingly random strings of numbers for the purpose of… well, your guess is as good as ours. If you want to try to figure out what’s going on for yourself, all you need is a pair of tape measures and a software define ..read more

On July 4th, 1976, as Americans celebrated the country’s bicentennial with beer and bottle rockets, a strong signal began disrupting shortwave, maritime, aeronautical, and telecommunications signals all over the world. The signal was a rapid 10 Hz tapping that sounded like a woodpecker or a helicopter thup-thupping on the roof. It had a wide bandwidth of 40 kHz and sometimes exceeded 10 MW. This was during the Cold War, and plenty of people rushed to the conclusion that it was some sort of Soviet mind control scheme or weather control experiment. But amateur radio operators traced the mysteri ..read more

In a world with software-defined radios and single-chip receivers, a superheterodyne shortwave radio might not exactly score high on the pizzazz scale. After all, people have been mixing, filtering, and demodulating RF signals for more than a century now, and the circuits that do the job best are pretty well characterized. But building the same receiver using none of the traditional superhet trappings? Now that’s something new. In what [Micha] half-jokingly calls a “74xx-Defined Radio”, easily obtained discrete logic chips, along with some op-amps and a handful of simple components, take the ..read more

If you are a ham radio operator, the idea of sending pictures and data over voice channels is nothing new. Hams have lots of techniques for doing that and — not so long ago — even most data transmissions were over phone lines. However, now everyone can get in on the game thanks to the cheap availability of software-defined radio. Several commercial shortwave broadcasters are sending encoded data including images and even entire web pages. You can find out more at the Swradiogram website. You can also find step-by-step instructions. WINB in Pennsylvania and WRMI Florida both have shows that in ..read more