Day: December 8, 2021

Ordering prototypes like they were fast food

Made To Spec: The Coming Age Of Prototyping As A Service

December 8, 2021 by 38 Comments

In the last decade, the price for making a single PCB plummeted. And we’ve featured tons of hacks with boards hailing from places like OSH Park or Seeed Studio. But this phenomenon isn’t isolated, and all sorts of one-off prototyping services are becoming cheaper and looking to satiate both hobbyist and engineer alike.

Today, I want to blow the lid off a few places offering one-off mechanical prototyping services. I’ll take us through some history of how we got here, introduce a few new players, and finally highlight some important tradeoffs before you start ordering bespoke aluminum parts straight to your doorstep.

Now go get your ANSI Z87+ safety glasses, and let’s get started.

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

December 8, 2021 by 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” →

Rubber Tyres Before There Were Tyres

December 8, 2021 by 24 Comments

Sometimes there is pleasure in watching an expert demonstrating his craft, particularly so when the craft is unusual or disappearing. A video came our way of just such a thing, and it’s of a craft so rare that it’s possible few of us will have considered it. We’re used to buying tyres for our motor vehicles that come pre-made in a mould for the size of our wheels, but how many of us have considered where the origins of the rubber tyre lie? How did a 19th-century horse-drawn buggy get its tyres? [EngelsCoachShop] take us through the process, putting rubber on a set of wooden carriage wheels.

These wheels would originally have had iron rims, that must have provided a jarring ride on cobbled roads of the day. English coach-builders of the mid 19th century were the first to fit solid rubber tyres, and it’s this type of tyre that’s being fitted in the video. Instead of the rubber ring we might expect the tyre is cut from a length of vulcanised rubber extrusion with a significant overlap, then a pair of high-tensile wires are fed through holes in the extrusion. The impressive part is the jig for creating the tyre, in which the rubber is compressed to a tight fit on the wheel before the wires are cut and their ends brazed together. Once the wheel is released from the jig  the compressed tyre expands to the point at which its ends meet, making a perfect circular tyre held tightly on the rim. Few of us will ever see this for real, but we’re privileged to see it on the screen.

We may not deal with wooden wheels very often, but this isn’t the first set we’ve seen.

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