Soviet-Era Test Gear Defects To YouTube

August 22, 2022 by Al Williams 3 Comments

If you want to work on communication gear — especially in the 1960s — you probably wanted a VTVM (a vacuum tube voltmeter), a way to generate frequencies, and a way to measure frequencies and power. The Soviet military had a piece of portable gear that could do all of this, the IK-2, and [msylvain59] shows up how one looked on the outside and the inside in the video below. Be warned, though. The video is hard to stop watching and it runs for over an hour, so plan accordingly.

We don’t read Russian, but based on the video, it looks like the lefthand piece of gear is a frequency generator that runs from 20 to 52 MHz and a power meter. The right-hand instrument is a VTVM that has some way to measure frequency and the center section is a quartz crystal frequency standard.

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SSB In Your Pocket

August 22, 2022 by Al Williams 66 Comments

In the old days, a shortwave radio was a major desk fixture. These days, you can get truly diminutive radios. However, most of them only have AM capability (that is, no simple way to receive single-sideband or SSB signals) and — maybe — the ability to pick up FM broadcast. Small radios also often have no provision for an external antenna which can be crucial for shortwave radios. [Farpoint Farms] shows off the Raddy RF7860 which is a palm-sided radio, but it has the elusive sideband modes and an external antenna port and wire antenna. It even has a rechargeable battery.

Reading the comments, it appears this is a rebadged version of a HanRongDa HRD 747 radio. Of course, there are other smaller radios with sideband reception like the Tecsun PL368, but they aren’t this small. If you are in the market for a really tiny shortwave radio, this might be the thing for you.

Of course, the question is what you want to listen to on the shortwave bands these days. There are fewer and fewer broadcasters on shortwave, especially those that broadcast to a general audience. However, if there is something you want to hear, pairing this radio with a good portable antenna, would do the job.

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Livestreaming Backpack Takes Streaming On-The-Go

August 19, 2022 by Bryan Cockfield 17 Comments

Anyone who’s anyone on the internet these days occasionally streams content online. Whether that’s the occasional livestream on YouTube or an every day video game session on Twitch, it’s definitely a trend that’s here to stay. If you want to take your streaming session on the go, though, you’ll need some specialized hardware like [Melissa] built into this livestreaming backpack.

[Melissa] isn’t actually much of a streamer but built this project just to see if it could be done. The backpack hosts a GoPro camera with a USB interface, mounted on one of the straps of the pack with some 3D printed parts, allowing it to act as a webcam. It is plugged into a Raspberry Pi which is set up inside the backpack, and includes a large heat sink to prevent it from overheating in its low-ventilation environment. There’s also a 4G modem included along with a USB battery pack to keep everything powered up.

The build doesn’t stop at compiling hardware inside a backpack, though. [Melissa] goes into detail on the project’s page about how to get all of the hardware to talk amongst themselves and where the livestream is setup as well. If you’d like a more permanently-located streaming setup with less expensive hardware, we have seen plenty of builds like this which will get the job done as well.

Liberated E-Ink Shelf Labels Turned 10×2 Display

August 4, 2022 by Al Williams 27 Comments

How expensive is it to make a panel that uses e-ink technology? That might depend on how flexible you are. [RBarron] read about reverse engineering point-of-sale shelf labels and found them on eBay for just over a buck apiece. Next thing you know, 20 of them were working together in a single panel.

The panels use RF or NFC programming, normally, but have the capability to use BLE. Naturally you could just address each one in turn, but that isn’t very efficient. The approach here is to use one label as a BLE controller and it then drives the other displays in a serial daisy chain, where each label’s receive pin is set to the previous label’s transmit pin.

That allows a simple piece of code to read incoming messages and process the ones addressed to that label. Anything else just gets sent out the serial port. Only the BLE node has special firmware. At first, we thought each label would need an address and we wondered how it would be set other than having unique firmware for each one since there doesn’t appear to be a handy way to do a hardware-based configuration.

The actual solution is clever. Each message has a hop counter that each node decrements before passing the message along the chain. When the hop count is zero, the message is at its destination. Simple and very easy to configure. In theory, you could replace any of the labels after the first one with any other label and the system would still work correctly.

Even the wiring is clever, with a jig to bend the wire to ensure even spacing of each element on the panel. A laser-cut box finishes the project off nicely. The code is all available on GitHub. We’ve seen these kinds of tags used for things like weather stations. Not to mention conference badges.

Ham Radio Hacking: Thinking Inside The Box

August 2, 2022 by Al Williams 19 Comments

There are two ways to deal with improving ham radio receivers, or — for that matter — any sort of receiver. You can filter and modify the radio frequency including the radio’s intermediate frequency, or you can alter the audio frequency output. Historically, RF and IF techniques have been the most valued because rejecting unwanted noise and signals early allows the rest of the radio to focus on the actual signal of interest. However, audio filters are much easier to work with and until recently, DSPs that could handle RF frequencies were expensive and uncommon. However, [watersstanton] shows us how to make what could be the cheapest audio enhancer ever. It is little more than a modified cardboard box, and you can see and hear the result in the video below.

On the one hand, you shouldn’t expect miracles. On the other hand, you probably have box laying around and can try it in the next three minutes so why not give it a go? You can hear a bit of difference when using the box and not using the box.

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LoRa Helps With Remote Water Tank Level Sensing

July 7, 2022 by Arya Voronova 9 Comments

[Renzo Mischianti]’s friend has to keep a water tank topped up. Problem is, the tank itself is 1.5 km away, so its water level isn’t typically known. There’s no electricity available there either — whichever monitoring solution is to be used, it has to be low-power and self-sufficient. To help with that, [Renzo] is working on a self-contained automation project, with a solar-powered sensor that communicates over LoRa, and a controller that receives the water level readings and powers the water pump when needed.

[Renzo] makes sure to prototype every part using shields and modules before committing to a design, and has already wrote and tested code for both the sensor and the controller, as well as created the PCBs. He’s also making sure to document everything as he goes – in fact, there’s whole seven blog posts on this project, covering the already completed software, PCB and 3D design stages of this project.

These worklogs have plenty of explanations and pictures, and [Renzo] shows a variety of different manufacturing techniques and tricks for beginners along the way. The last blog post on 3D designing and printing the sensor enclosure was recently released, and that likely means we’ll soon see a post about this system being installed and tested!

[Renzo] has been in the “intricately documented worklogs” business for a while. We’ve covered his 3D printed PCB mill and DIY soldermask process before, and recently he was seen adding a web interface to a 3D printer missing one. As for LoRa, there’s plenty of sensors you can build – be it mailbox sensors, burglar alarms, or handheld messengers; and now you have one more project to draw inspiration and knowledge from. [Renzo] has previously done a LoRa tutorial to get you started, and we’ve made one about LoRaWAN!

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Headphones described in article, charging off a powerbank through an orange USB cable

Headphone Cable Trouble Inspires Bluetooth Conversion

July 6, 2022 by Arya Voronova 12 Comments

[adblu] encountered the ever-present headphone problem with their Sennheiser Urbanite headphones – the cable broke. These headphones are decent, and despite the cable troubles, worth giving a new life to. Cable replacement is always an option, but [adblu] decided to see – what would it take to make these headphones wireless? And while they’re at it, just how much battery life could they get?

Armed with a CSR8635 Bluetooth audio receiver breakout module and a TP4056 charger, [adblu] went on rewiring the headphone internals. The CSR8635 already has a speaker amplifier inside, so connecting the headphones’ speakers didn’t require much effort – apart from general soldering difficulties, as [adblu]’s soldering iron was too large for the small pads on the BT module. They also found a 2400mAh battery, and fit it inside the headphone body after generous amounts of dremel work.

The result didn’t disappoint – not only does everything fit inside the headphone body, the headphones also provided 165 hours of music playback at varying volume. Electronics-wise, it really is that easy to retrofit your headphones with Bluetooth, but you can always go the extra mile and design an intricate set of custom PCBs! If firmware hacks are more to your liking, you can use a CSR8645 module for your build and then mod its firmware.