Homemade Panadapter Brings Waterfall To Old Radio

February 20, 2022 by Adam Zeloof 16 Comments

Ham radio operators can be pretty selective about their gear. Some are old-school tube purists who would never think of touching a rig containing transistors, and others are perfectly happy with the small Software Defined Radio (SDR) hooked up to their PC. The vast majority, though, of us are somewhere in between — we appreciate the classic look and feel of vintage radios as well as the convenience of modern ones. Better yet, some of us even like to combine the two by adding a few modern bells and whistles to our favorite “boat anchor.”

[Scott Baker] is one such Ham. He’s only had his license for a few months now and has already jumped into some great projects, including adding a panadapter to an old Drake R-4B Receiver. What’s a panadapter, you may ask? As [Scott] explains in his excellent writeup and video, a panadapter is a circuit that grabs a wideband signal from a radio receiver that typically has a narrowband output. The idea is that rather than just listen to somebody’s 4kHz-wide transmission in the 40m band, you can listen to a huge swath of the spectrum, covering potentially hundreds of transmissions, all at the same time.

Well, you can’t actually listen to that many transmissions at once — that would be a garbed mess. What you can do with that ultrawide signal, however, is look at it. If you take an FFT of the signal to put it in the frequency domain (by using a spectrum analyzer, or in [Scott]’s case, an SDR), you can see all sorts of different signals up and down the spectrum. This makes it a heck of a lot easier to find something to listen to — rather than spinning the dial for hours, hoping to come across a transmission, you can just see where all of the interesting signals are.

This isn’t the first (or even the twentieth) time that [Scott]’s work has graced our pages, so make sure to check some of his other incredible projects in our archives!

Continue reading “Homemade Panadapter Brings Waterfall To Old Radio” →

This End Times Cyberdeck Is Apocalypse-Ready

January 21, 2022 by Dan Maloney 29 Comments

In the cyberdeck world, some designs are meant to evoke a cyberpunk vibe, an aesthetic that’s more lighthearted than serious. Some cyberdecks, though, are a little more serious about hardening their designs against adverse conditions. That’s where something like the ARK-io SurvivalDeck comes into play.

Granted, there does seem to be at least a little lightheartedness at play with the aptly named [techno-recluse]’s design. It’s intended to be an “Apocalypse Repository of Knowledge”, which may be stretching the point a bit. But it does contain an impressive amount of tech — wide-band software defined radio (SDR) covering HF to UHF, GPS module, a sensor for air pressure, temperature, and humidity, and a Raspberry Pi 3B running Kali Linux. Everything is housed in a waterproof ammo can; a 3D printed bezel holds an LCD touchscreen and a satisfying array of controls, displays and ports. The lid of the ammo can holds a keyboard, which was either custom-made to precisely fit the lid or was an incredibly lucky find.

There’s a lot to like about this build, but our favorite part is the external dipole for receiving NOAA weather satellite imagery. The ability to monitor everything from the ham bands to local public service channels is a nice touch too. And we have no complaints about the aesthetics or build quality either. This reminds us of an earlier cyberdeck with a similar vibe, but with a more civilian flavor.

Thanks to [Kate] for the tip.

[via Tom’s Hardware]

Affordable HF Loop Antenna Reviewed

January 21, 2022 by Al Williams 10 Comments

Modern ham radio operators often face restrictions on antennas. This has made small antennas more popular, despite some limitations. [Tech Minds] reviews the GA-450 indoor active HF loop antenna and finds it better than expected. You can see the video review below.

You can’t expect a little antenna to perform as well as giant skyhook. However, for such a small loop covering 3 to 30 MHz, the antenna seems to perform very well. We like that the active part of it has a rechargeable battery. Obviously, you will only want to use this antenna for receiving, but it would be a great pairing for an HF-capable software defined radio (SDR). Even just in the window sill with half gain, it was able to pick up quite a bit of signal on the 40 meter and 20 meter ham bands. According to the video, performance below 7 MHz was lackluster, but it worked nicely at higher frequencies.

The loop is directional and you can rotate the loop on the base to zero in on a particular signal. Of course, if the antenna were up in the air, it might be harder to rotate unless you work out something with a motor. If all you want to do is receive and you have a budget of under $100, this looks like it would be a nice portable option.

You can build your own loop and loop-like antennas, of course. Some of them can be quite portable.

Continue reading “Affordable HF Loop Antenna Reviewed” →

SDR Toolkit Bends Weather Station To Hacker’s Whims

December 17, 2021 by Tom Nardi 9 Comments

We probably don’t have to tell most Hackaday readers why the current wave of low-cost software defined radios (SDRs) are such a big deal for hackers looking to explore the wide world of wireless signals. But if you do need a refresher as to what kind of SDR hardware and software should be in your bag of tricks, then this fantastically detailed account from [RK] about how he hacked his La Crosse WS-9611U-IT weather station is a perfect example.

Looking to brush up his radio hacking skills, [RK] set out to use the ADALM-PLUTO software defined radio from Analog Devices to intercept signals between the La Crosse base station and its assorted wireless sensors. He notes that a $20 USD RTL-SDR dongle could do just as well if you only wanted to receive, but since his ultimate goal was to spoof a temperature sensor and introduce spurious data into the system, he needed an SDR that had transmit capabilities.

No matter your hardware, Universal Radio Hacker (URH) is the software that’s going to be doing the heavy lifting. In his write-up, [RK] walks the reader through every step required to find, capture, and eventually decode the transmissions coming from a TX29U wireless temperature sensor. While the specifics will naturally change a bit depending on the device you’re personally looking to listen in on, the general workflow is going to be more or less the same.

In the end, [RK] is not only able to receive the data coming from the wireless sensors, but he can transmit his own spoofed data that the weather station accepts as legitimate. Getting there took some extra effort, as he had to figure out the proper CRC algorithm being used. But as luck would have it, he found a Hackaday article from a couple years back that talked about doing exactly that, which help put him on the right path. Now he can make the little animated guy on the weather station’s screen don a winter coat in the middle of July. Check out the video below for a demonstration of this particular piece of radio prestidigitation.

Continue reading “SDR Toolkit Bends Weather Station To Hacker’s Whims” →

Ham Radio SSB Transceiver Fits In Pocket

December 9, 2021 by Al Williams 32 Comments

Talking about this Chinese ham radio transceiver requires a veritable flurry of acronyms: HF, SSB, QRP, and SDR to start with. [Paul] does a nice job of unboxing the rig and checking it out. The radio is a clone of a German project and provides a low-power radio with a rechargeable battery. You can see his video about the gear below.

SSB is an odd choice for low power operation, although we wonder if you couldn’t feed digital data in using a mode like PSK31 that has good performance at low power. There are several variations of the radio available and they cost generally less than $200 — sometimes quite a bit less.

There isn’t much on the front of the radio. There are a few buttons, a rotary encoder, and an LCD along with a speaker and microphone built-in. There are ports for power to run the radio if you want to not use the battery and a separate port for battery charging. There are also ports for a key, external microphone and speakers, and audio connections that look like they’d work for digital modes. According to commenters, the radio doesn’t have an internal charging circuit, so you have to be careful what you plug into the charging port.

Looking inside, the radio looks surprisingly well made. Towards the end of the video, you can see the radio make some contacts, too. Looks like fun. This is a bit pricey for [Dan Maloney’s] $50 Ham series, but not by much. You might borrow an antenna idea from him, at least. If you prefer something more analog, grab seven transistors and build this SSB transceiver.

Continue reading “Ham Radio SSB Transceiver Fits In Pocket” →

Four Band Digital HF SDR Transceiver Offers High Performance For Only $60

December 8, 2021 by Ryan Flowers 31 Comments

Amateur radio is a hobby that is often thought of as being exclusive to those with a healthy expendable income. In recent years however, the tides have turned. Cheap microcontrollers and signal generators have helped turned things around, and the $60 USD QDX from QRP Labs goes even further by sending the performance/price ratio through the roof. You can see more details in the video below the break.

The QDX is the creation of [Hans Summers] who is well known for producing affordable high performance amateur radio kits that are focused on low power transmission, called “QRP” in ham radio parlance. What is it? It’s a pocket sized four band (80, 40, 30, 20 Meters) software defined radio (SDR) that is designed to be used with some of the most popular digital radio modes: FT8 and JS8Call, as well as any other FSK based mode such as RTTY. It’s also been tested to work well (and within spec) on 60 Meters.

While classic radios have to be connected to a computer through a special hardware interface, the QDX is designed to connect directly to a computer through a standard USB A>B cable. CAT control, PTT, and Audio are all handled directly by the QDX, and no special interface is needed. While the radio is essentially plug and play, configuration, testing, and troubleshooting can be done by connecting to the QDX’s unique serial console, which among other things contains a text based waterfall. For those who want to run their own SDR receiver, I/Q output can be sent directly through the sound card.

Now for the bad news: due to global chip shortages, the QDX is out of stock at the moment, and there’s no telling when they might start shipping again. QRP Labs is looking to source parts wherever they can to get more of the units made, but of course, so is everyone else right now. Continue reading “Four Band Digital HF SDR Transceiver Offers High Performance For Only $60” →

Detect Starlink Satellites Passing By

November 29, 2021 by Bryan Cockfield 16 Comments

The Starlink beta has semi-officially ended, but it seems as though the global chip shortage is still limiting how many satellites are flying around the world for broadband internet access for those that might not be served by traditional ISPs. Not every location around the world has coverage even if you can get signed up, so to check that status the hard way you can always build a special antenna that tracks the Starlink beacons as they pass overhead.

[Derek] is using this project to show of some of his software-defined radio skills, so this will require an SDR that can receive in the 1600 MHz range. It also requires a power injector to power the satellite receiver, but these are common enough since they are used to power TV antennas. The signals coming from the Starlink satellites have a very high signal-to-noise ratio so [Derek] didn’t even need a dish to focus the signals. This also helped because the antenna he is using was able to see a much wider area as a result. Once everything was set up and the computer was monitoring the correct location in the spectrum, he was able to see very clearly how often a satellite passed him by.

Of course, [Derek] lives in an area with excellent coverage so this might be a little more difficult for those in rural areas, but possibly not for long as the goal of Starlink is to bring broadband to people who otherwise wouldn’t have access to it. There is some issue with how much these satellites might interfere with other astronomical activities though, so take that with a grain of salt.

Thanks to [Spritle] for the tip!