Retrotechtacular

291 Articles

Retrotectacular: Ham Radio As It Was

February 21, 2025 by 21 Comments

We hear a lot about how ham radio isn’t what it used to be. But what was it like? Well, the ARRL’s film “The Ham’s Wide World” shows a snapshot of the radio hobby in the 1960s, which you can watch below. The narrator is no other than the famous ham [Arthur Godfrey] and also features fellow ham and U.S. Senator [Barry Goldwater]. But the real stars of the show are all the vintage gear: Heathkit, Swan, and a very oddly placed Drake.

The story starts with a QSO between a Mexican grocer and a U.S. teenager. But it quickly turns to a Field Day event. Since the film is from the ARRL, the terminology and explanations make sense. You’ll hear real Morse code and accurate ham lingo.

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Retrotechtacular: Yamming CRT Yokes

February 19, 2025 by 28 Comments

Those of us who worked in TV repair shops, back when there was such a thing, will likely remember the cardinal rule of TV repair: Never touch the yoke if you can help it. The complex arrangement of copper wire coils and ferrite beads wrapped around a plastic cone attached to the neck of the CRT was critical to picture quality, and it took very little effort to completely screw things up. Fixing it would be a time-consuming and frustrating battle with the cams, screws, and spacers that kept the coils in the right orientation, both between themselves and relative to the picture tube. It was best to leave it the way the factory set it and to look elsewhere for solutions to picture problems.

But how exactly did the factory set up a deflection yoke? We had no idea at the time, only learning just recently about the wonders of automated deflection yoke yamming. The video below was made by Thomson Consumer Electronics, once a major supplier of CRTs to the television and computer monitor industry, and appears directed to its customers as a way of showing off their automated processes. They never really define yamming, but from the context of the video, it seems to be an industry term for the initial alignment of a deflection yoke during manufacturing. The manual process would require a skilled technician to manipulate the yoke while watching a series of test patterns on the CRT, slowly tweaking the coils to bring everything into perfect alignment.

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Retrotechtacular: Point-of-Sale Through The Years

February 8, 2025 by 13 Comments

In days gone by, a common retail hack used by some of the less honorable of our peers was the price tag switcheroo. You’d find some item that you wanted from a store but couldn’t afford, search around a bit for another item with a more reasonable price, and carefully swap the little paper price tags. As long as you didn’t get greedy or have the bad luck of getting a cashier who knew the correct prices, you could get away with it — at least up until the storekeeper wised up and switched to anti-tamper price tags.

For better or for worse, those days are over. The retail point-of-sale (POS) experience has changed dramatically since the time when cashiers punched away at giant cash registers and clerks applied labels to the top of every can of lima beans in a box with a spiffy little gun. The growth and development of POS systems is the subject of [TanRu Nomad]’s expansive video history, and even if you remember the days when a cashier kerchunked your credit card through a machine to take an impression of your card in triplicate, you’ll probably learn something.

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Retrotechtacular: The Tyranny Of Large Numbers

January 30, 2025 by 3 Comments

Although much diminished now, the public switched telephone network was one of the largest machines ever constructed. To make good on its promise of instant communication across town or around the world, the network had to reach into every home and business, snake along poles to thousands of central offices, and hum through the ether on microwave links. In its heyday it was almost unfathomably complex, with calls potentially passing through thousands of electronic components, any of which failing could present anything from a minor annoyance to a matter of life or death.

The brief but very interesting film below deals with “The Tyranny of Large Numbers.” Produced sometime in the 1960s by Western Electric, the manufacturing arm of the Bell System, it takes a detailed look at the problems caused by scaling up systems. As an example, it focuses on the humble carbon film resistor, a component used by the millions in various pieces of telco gear. Getting the manufacturing of these simple but critical components right apparently took a lot of effort. Initially made by hand, a tedious and error-prone process briefly covered in the film, Western Electric looked for ways to scale up production significantly while simultaneously increasing quality.

While the equipment used by the Western engineers to automate the production of resistors, especially the Librascope LGP-30 computer that’s running the show, may look quaint, there’s a lot about the process that’s still used to this day. Vibratory bowl feeders for the ceramic cores, carbon deposition by hot methane, and an early version of a SCARA arm to sputter gold terminals on the core could all be used to produce precision resistors today. Even cutting the helical groove to trim the resistance is similar, although today it’s done with a laser instead of a grinding wheel. There are differences, of course; we doubt current resistor manufacturers look for leaks in the outer coating by submerging them in water and watching for bubbles, but that’s how they did it in the 60s.

The productivity results were impressive. Just replacing the silver paint used for terminal cups with sputtered gold terminals cut 16 hours of curing time out of the process. The overall throughput increased to 1,200 pieces per hour, an impressive number for such high-reliability precision components, some of which we’d wager were still in service well into the early 2000s. Most of them are likely long gone, but the shadows cast by these automated manufacturing processes stretch into our time, and probably far beyond.

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Retrotechtacular: The 1951 Telephone Selector

January 11, 2025 by 20 Comments

Telephone systems predate the use of cheap computers and electronic switches. Yesterday’s phone system used lots of stepping relays in a box known as a “selector.” If you worked for the phone company around 1951, you might have seen the Bell System training film shown below that covers 197 selectors.

The relays are not all the normal ones we think of today. There are slow release relays and vertical shafts that are held by a “dog.” The shaft moves to match the customer’s rotary dial input.

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Retrotechtacular: Soldering The Tek Way

January 9, 2025 by 40 Comments

For a lot of us, soldering just seems to come naturally. But if we’re being honest, none of us was born with a soldering iron in our hand — ouch! — and if we’re good at soldering now, it’s only thanks to good habits and long practice. But what if you’re a company that lives and dies by the quality of the solder joints your employees produce? How do you get them to embrace the dark art of soldering?

If you’re Tektronix in the late 1970s and early 1980s, the answer is simple: make in-depth training videos that teach people to solder the Tek way. The first video below, from 1977, is aimed at workers on the assembly line and as such concentrates mainly on the practical aspects of making solid solder joints on PCBs and mainly with through-hole components. The video does have a bit of theory on soldering chemistry and the difference between eutectic alloys and other tin-lead mixes, as well as a little about the proper use of silver-bearing solders. But most of the time is spent discussing the primary tool of the trade: the iron. Even though the film is dated and looks like a multi-generation dupe from VHS, it still has a lot of valuable tips; we’ve been soldering for decades and somehow never realized that cleaning a tip on a wet sponge is so effective because the sudden temperature change helps release oxides and burned flux. The more you know.

The second video below is aimed more at the Tek repair and rework technicians. It reiterates a lot of the material from the first video, but then veers off into repair-specific topics, like effective desoldering. Pro tip: Don’t use the “Heat and Shake” method of desoldering, and wear those safety glasses. There’s also a lot of detail on how to avoid damaging the PCB during repairs, and how to fix them if you do manage to lift a trace. They put a fair amount of emphasis on the importance of making repairs look good, especially with bodge wires, which should be placed on the back of the board so they’re not so obvious. It makes sense; Tek boards from the era are works of art, and you don’t want to mess with that.

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Size comparison of a 27 in CRT TV next to a 43 in CRT TV.

Retrotechtacular: Quest For The “Big Boy” CRT Finds New Home In Mini Doc

December 24, 2024 by 36 Comments

To celebrate the twentieth anniversary of their Trinitron line of televisions, Sony launched the KX-45ED1. At forty three inches the screen on this particular model made it the largest tube television in the world, and it came with the kind of price tag that if you need to ask…you can’t afford it (likely around $100,000 USD today). Three decades later, only two of these mythical displays were thought to exist and [shank] chronicled his quest to acquire one of the last remaining “Big Boys” in the mini documentary below.

As it turns out, one of these gigantic tube televisions was located on the second floor of a restaurant in Japan still sitting in the same place it was installed in 1989. It hadn’t moved in the intervening decades, because the television and its specialized support stand weighed over 500 pounds. Having an object that heavy physically moved down a flight of stairs would seem to be the most formidable challenge for most, but compounding the issue for [shank] was that the building housing this colossal CRT was set to be permanently closed in less than a week.

With next to no time to arrange an international flight, [shank] utilized the power of internet to ask for help from anyone currently living near the “Big Boy” CRT’s soon-to-be final resting place. It just so happened that a fellow retro tech enthusiast based in Japan saw the post, and traveled over an hour by train at a moment’s notice to aid [shank]. The heartwarming story of total strangers united by a common interest of preserving a rare piece of tech history is certainly worth a watch. Let alone the goofy size comparison footage of the smallest CRT display sitting on top of the biggest one.

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