Rants

458 Articles

My Beef With Ham Radio

December 12, 2016 by 371 Comments

My amateur radio journey began back in the mid-1970s. I was about 12 at the time, with an interest in electronics that baffled my parents. With little to guide me and fear for my life as I routinely explored the innards of the TVs and radios in the house, they turned to the kindly older gentleman across the street from us, Mr. Brown. He had the traditional calling card of the suburban ham — a gigantic beam antenna on a 60′ mast in the backyard – so they figured he could act as a mentor to me.

Mr. Brown taught me a lot about electronics, and very nearly got me far enough along to take the test for my Novice class license. But I lost interest, probably because I was an adolescent male and didn’t figure a ham ticket would improve my chances with the young ladies. My ham ambitions remained well below the surface as life happened over the next 40 or so years. But as my circumstances changed, the idea of working the airwaves resurfaced, and in 2015 I finally took the plunge and earned my General class license.

The next part of my ham story is all-too-familiar these days: I haven’t done a damn thing with my license. Oh, sure, I bought a couple of Baofeng and Wouxun handy-talkies and lurked on the local repeaters. I even bought a good, solid HF rig and built some antennas, but I’ve made a grand total of one QSO — a brief chat with a ham in Texas from my old home in Connecticut on the 10-meter band. That’s it.

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Sensing A Magnet With Local Sourcing

December 8, 2016 by 48 Comments

I had a small project going on–never mind exactly what–and I needed to detect a magnet. Normally, that wouldn’t be a big problem. I have a huge hoard of components and gear to the point that it is a running joke among my friends that we can be talking about building something and I will have all the parts we need. However, lately a lot of my stuff is in… let’s say storage (again, never mind exactly why) and I didn’t have anything handy that would do the job.

Options

If I had time, there are plenty of options for detecting a magnet. Even if you ignore exotic things like SQUID (superconducting quantum interference device) there’s plenty of ways to detect a magnet. One of the oldest and the simplest is to use a reed switch. This is just a switch made with a thin piece of ferrous material. When a magnet is nearby, the thin piece of metal moves and makes or breaks the contact.

These used to be common in alarm systems to detect an open or closed door. However, a trip to Radio Shack revealed that they no longer carry things like that as–apparently–it cuts into floorspace for the cell phones.

I started to think about robbing a sensor from an old computer fan or some other consumer item with a magnetic sensor onboard. I also thought about making some graphene and rolling my own Hall effect sensor, but decided that was too much work.

Browsing

I was about to give up on Radio Shack, but decided to skim through the two cabinets of parts they still carry just to get an idea of what I could and could not expect to find in the future. Then something caught my eye. They still carry a wide selection of relays. (Well, perhaps wide is too kind of a word, but they had a fair number.) It hit me that a relay is a magnetic device, it just generates its own electromagnetic field to open and close the contacts.

I picked up a small 5 V reed relay. They don’t show it online, but they do have several similar ones, so you can probably pick up something comparable at your local location. I didn’t want to get a very large relay because I figured it would take more external magnetic field to operate the contacts. You have to wonder why they have so many relays, unless they just bought a lot and are still selling out of some warehouse. Not that relays don’t have their use, but there’s plenty of better alternatives for almost any application you can think of.

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You Can Have My LM386s When You Pry Them From My Cold Dead Hands

December 7, 2016 by 137 Comments

Everyone has a chip-of-shame: it’s the part that you know is suboptimal but you keep using it anyway because it just works well enough. Maybe it’s not what you would put into a design that you’re building more than a couple of, but for a quick and dirty lashup, it’s just the ticket. For Hackaday’s [Adam Fabio], that chip is the TIP120 transistor. Truth be told, we have more than one chip of shame, but for audio amplification purposes, it’s the LM386.

The LM386 is an old design, and requires a few supporting passive components to get its best performance, but it’s fundamentally solid. It’s not noise-free and doesn’t run on 3.3 V, but if you can fit a 9 V battery into your project and you need to push a moderate amount of sound out of a speaker, we’ll show you how to get the job done with an LM386.

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Crypto Features: They’re Not For Girls

December 5, 2016 by 56 Comments

If you have worked in an office that contained a typewriter, the chances are you’ve been in the workplace for several decades. Such has been the inexorable advance of workplace computing. It’s a surprise then to discover that one of the desirable toys from many decades ago, the Barbie Typewriter, is still available. Are hipster parents buying toy versions of vintage office machinery for their children to use in an ironic fashion?

Gone though are the plastic versions of mechanical typewriters that would have been the property of a 1970s child. The modern Barbie typist has an electronic typewriter at her fingertips, with a daisy-wheel printer. We’re treated to a teardown of the recent models courtesy of Crypto Museum, who reveal a hidden feature, Barbie’s typewriter can encrypt and decrypt messages.

Now the fact that a child’s toy boasts a set of simple substitution cyphers is hardly the kind of thing that will set the pulses of Hackaday readers racing, after all simple letter frequency analysis is hardly new. But of course, the Crypto Museum angle is only part of this story.

This toy is made in a suitably eye-watering shade of pink, and sold by Mattel with Barbie branding. But it didn’t start life as a Barbie product, instead it’s licensed from the Slovenian manufacturer Mehano. The original toy makes no secret of the crypto functions, but though they persist in the software on the Barbie version they are mysteriously absent from the documentation. The achievements of American women are such that they have given us high-level languages and compilers, or their software has placed men on the Moon, yet it seems when they are young a brush with elementary cryptology is beyond them in the way that it isn’t for their Slovenian sisters. This is no way to nurture a future Grace Hopper or Margaret Hamilton, though sadly if your daughter is a Lisa Simpson this is just one of many dumbed-down products she’ll be offered.

If you see a Barbie electronic typewriter in a yard sale or similar, and you can pick it up for a few dollars, buy it. It’s got a simple daisywheel printer mechanism that looks eminently hackable. Just don’t buy it for your daughter without also printing out the Crypto Museum page for her as the missing manual.

When the Martian lander running her code has touched down safely, you’ll be glad you did.

Via Adafruit.

Self-Driving Cars Are Not (Yet) Safe

December 5, 2016 by 123 Comments

Three things have happened in the last month that have made me think about the safety of self-driving cars a lot more. The US Department of Transportation (DOT) has issued its guidance on the safety of semi-autonomous and autonomous cars. At the same time, [Geohot]’s hacker self-driving car company bailed out of the business, citing regulatory hassles. And finally, Tesla’s Autopilot has killed its second passenger, this time in China.

At a time when [Elon Musk], [President Obama], and Google are all touting self-driving cars to be the solution to human error behind the wheel, it’s more than a little bold to be arguing the opposite case in public, but the numbers just don’t add up. Self-driving cars are probably not as safe as a good sober driver yet, but there just isn’t the required amount of data available to say this with much confidence. However, one certainly cannot say that they’re demonstrably safer.

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Automate The Freight: Robotic Deliveries Are On The Way

November 23, 2016 by 162 Comments

Seems like all the buzz about autonomous vehicles these days centers around self-driving cars. Hands-free transportation certainly has its appeal – being able to whistle up a ride with a smartphone app and converting commute time to Netflix binge time is an alluring idea. But is autonomous personal transportation really the killer app that everyone seems to think it is? Wouldn’t we get more bang for the buck by automating something a little more mundane and a lot more important? What about automating the shipping of freight?

Look around the next time you’re not being driven to work by a robot and you’re sure to notice a heck of a lot of trucks on the road. From small panel trucks making local deliveries to long-haul tractor trailers working cross-country routes, the roads are lousy with trucks. And behind the wheel of each truck is a human driver (or two, in the case of team-driven long-haul rigs). The drivers are the weak point in this system, and the big reason I think self-driving trucks will be commonplace long before we see massive market penetration of self-driving cars.

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Heathkit: Getting Closer This Time?

November 21, 2016 by 81 Comments

We’ve been following the Heathkit reboot for a while now, and it looks like the storied brand is finally getting a little closer to its glory days. I was thumbing through the new issue of QST magazine while I was listening in on a teleconference for the day job – hey, a guy can multitask, can’t he? – when I spied an ad for the Heathkit GC-1006 digital clock, which they brand the “Most Reliable Clock”. As soon as the meeting was over, I headed over to the Heathkit website to check out this latest offering.

I had cautiously high hopes. After the ridiculous, feature-poor, no-solder AM radio kit (although they sensibly followed up with a solder version of that kit) and an overpriced 2-meter ham antenna, I figured there was nowhere for Heathkit to go but up. And the fact that the new kit was a clock was encouraging. I have fond memories of Heathkit clocks from the 80s when I worked in a public service dispatch center; Heathkit clocks were about the only clocks you could get that would display 24-hour time. Could this actually be a kit worth building?

Alas, the advertisement was another one of those wall-of-text things that the new Heathkit seems so enamored of. And like the previous two kits offered, the ad copy is full of superlatives and cutesy little phrases that really turn me off. Then again, most advertising turns me off, so I’m probably not a good gauge of such things. Nor am I sure I’m in the target demographic for this product – in fact, I’m not even sure to whom this product is being marketed. Is it the younger crowd of the maker movement? Or is it the old-timers who want to relive the glory days of Heathkit builds? Given the $100 price, I’d have to say the nostalgia market is the most likely buyer of this one.

To be fair, $100 might not be that much to spend on a decent clock. I’m a bit of a clock snob, and I’ve gotten to the point where I can almost tell which chip is in a clock just by looking at the controls. The feature set of a modern digital clock has converged to a point where every clock has almost exactly the same deficiencies. The GC-1006 claims to address a few of my hot button issues, like not being able to set the time to the exact second – I hate that! An auto-dimming display is nice, as is a 12- or 24-hour display, a 10-minute timer (nice for hams, who are required to ID their station every 10 minutes), and a battery backup that claims to last for 4 weeks.

Is this worth buying? At this point, I’m on the fence. Looking at an unboxing video, it appears to be a high-quality kit, and it would be fun to build. But spending $100 on a clock might be a tough sell to my loan officer.

Still, I think I might take one for the team here so we have a first-hand report of what the new Heathkit is all about. And it would be nice to build another Heathkit product. I’ll let you know how it goes.

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