The Bad Old Days of Telephone Answering Machines

Telephone answering machines were almost a fad. They were hindered for years by not being allowed to connect to the phone lines. Then a mix of cell phones and the phone company offering voicemail made the machines all but obsolete. Unless you are really young, you probably had one at some point though. Some had digital outgoing messages and a tape to record. Some had two tapes. But did you ever have one that didn’t connect to the phone line at all? Remember, there was a time when they couldn’t. My family had one of these growing up and after doing enough research to find it in an old catalog, I decided you might like to know how it really worked.

Even if you grew up in the 1960s and 1970s, it is hard to imagine how little technology there was in an average person’s home at that time. You probably had one TV and one wired telephone. You probably had a radio or two and maybe even a record or tape player. If you were very fancy, you had a big piece of furniture that had a TV, a turntable, a radio, and a tape player in it. No cell phones, no computers, no digital assistant, and appliances were electro-mechanical and didn’t have displays. So when you saw a new piece of tech — especially if you were a kid who didn’t know what a hacker was, but still wanted to be one — it made an impression.

I still remember the first time I even saw a tape recorder. I was amazed! But a tape recorder is a far cry from a telephone answering machine.

A Bit of Background

My Dad always had a regular job and his side business. He had a lot of different side businesses at one time or another, but he was always concerned about missing a phone call from a customer. We had two phones: the old wall mount phone with a dial and another desk phone in the “store” (the front room of the house) which also had a dial — we were way too cheap to pay for TouchTone service.

Remember, there was no call waiting and getting a second phone line was out of the question for my frugal parents. So they were always nervous about keeping the phone line clear during the day. But if you had to leave, you might miss a call. What do you do about that?

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Diode Recovery Time Explained

There are at least two phases to learning about electronics. In the first phase, you learn about how components are supposed to work. In the second phase, you learn about how they really work. Wires have resistance and inductance. Adjacent wires have capacitance. Capacitors leak. Inductors have resistance. All of these things matter. [Learnelectronics] has a recent video that explores recovery time for a diode — a phase two conversation.

If you haven’t run into recovery time before, it is the amount of time the diode takes to shut off after it is conducting. This manifests itself as a little undershoot where the signal that the diode should block leaks through briefly.

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Ham-designed Gear Used in Thailand Cave Rescue

Unless you live in a cave, you’ve probably heard a little about the thirteen people — mostly children — trapped in the Tham Luang Nang Non cave in Thailand. What you may have missed, though, is the hacker/ham radio connection. The British Cave Rescue Council (BCRC) was asked for their expert help. [Rick Stanton], [John Volanthen] and [Rob Harper] answered the call. They were equipped with HeyPhones. The HeyPhone is a 17-year-old design from [John Hey, G3TDZ]. Sadly, [G3TDZ] is now a silent key (ham radio parlance for deceased) so he didn’t get to see his design play a role in this high-profile rescue, although it has apparently been a part of many others in the past.

The HeyPhone is actually considered obsolete but is still in service with some teams. The radio uses USB (upper sideband, not universal serial bus) at 87 kHz. The low frequency can penetrate deep into the ground using either induction loop antennas like the older Molephone, or — more commonly — with electrodes injecting RF energy directly into the ground.

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Flawed Synthetic Diamonds May Be Key For Quantum Computing

If you’ve followed any of our coverage of quantum computing, you probably know that the biggest challenge is getting quantum states to last very long, especially when moving them around. Researchers at Princeton may have solved this problem as they demonstrate storing qubits in a lab-created diamond. The actual publication is behind a paywall if you want to learn even more.

Generally, qubits are handled as photons and moved in optical fibers. However, they don’t last long in that state and it is difficult to store photons with correct quantum information. The impurities in diamonds though may have the ability to transfer a photon to an electron and back.

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Do You Need A Solder Fume Extractor?

We’ll admit it. Most of us have been soldering since we were kids and we don’t think of it as a particularly dangerous activity. Just keep the hot and cold end of the iron straight and remember not to flick solder off the tip on your leg and you are fine. We sometimes roll our eyes a bit at the people with the soldering fume extractors unless you are soldering 8 hours a day, although we’ve occasionally used a small fan nearby just to get some circulation. [Tanner Tech’s] video on soldering fumes might make us rethink that, though (see below).

[Tanner] rigs up a fan with some plastic bottles, fans, and some cotton balls. But that didn’t do very much. Instead, he replaced his fan assembly with a shop vac. Then he examined what was on the cotton balls.

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Amiga 2000 Emergency Repair

Big companies spend small fortunes on making sure their computers stay running and that they can be repaired quickly in an emergency. You wouldn’t expect an emergency repair on an Amiga 2000, though. [RETR-O-MAT] bought an Amiga 2000 that did boot, but was known to have a leaky battery on the motherboard. He wanted to rush to replace the battery before the leakage caused serious damage. You can see all this in the video below.

The computer looked lightly used over its 32-year lifespan, even when the case came off. The battery corrosion was evident, though. Even the bolt holding down the motherboard was clearly corroded from the leaking battery, causing it to be very difficult to remove.

The battery leakage also made unsoldering the battery a challenge. Several chips and sockets — including the CPU — were affected, so they had to come out. You can see a nice demonstration of the “old screwdriver trick” which might be eye-opening if you’ve only worked with SMD chips.

Even if you don’t care much about the Amiga 2000, it is interesting to see inside an old computer like this and note the differences — and similarities — to modern designs. The video is as much a tear down as it is a repair story. It also might be useful if you ever face having to tear out a leaky battery on any piece of gear. Continue reading “Amiga 2000 Emergency Repair”

Tiny Websites have no Server

A big trend in web services right now is the so-called serverless computing, such as Amazon’s Lambda service. The idea is you don’t have a dedicated server waiting for requests for a specific purpose. Instead, you have one server (such as Amazon’s) listening for lots of requests and on demand, you spin up an environment to process that request. Conceptually, it lets you run a bit of Javascript or some other language “in the cloud” with no dedicated server.  https://itty.bitty.site takes this one step farther. The site creates self-contained websites where the content is encoded in the URL itself.

Probably the best example is to simply go to the site and click on “About itty bitty.” That page is itself encoded in its own URL. If you then click on the App link, you’ll see a calculator, showing that this isn’t just for snippets of text. While this does depend on the itty.bitty.site web host to provide the decoding framework, the decoding is done totally in your browser and the code is open source. What that means is you could host it on your own server, if you wanted to.

At first, this seems like a novelty until you start thinking about it. A small computer with an Internet connection could easily formulate these URLs to create web pages. A bigger computer could even host the itty.bitty server. Then there’s the privacy issue. At first, we were thinking that a page like this would be hard to censor since there is no centralized server with the content. But you still need the decoding framework. However, that wouldn’t stop a sophisticated user from “redirecting” to another — maybe private — decoding website and reading the page regardless of anyone’s disapproval of the content.

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