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Weekend project highlight
Learn all about radio.
One cheap USB stick, the Nooelec NESDR SMArt v5, turns a laptop into a receiver for aircraft, ships, weather satellites, the space station and free-to-air TV. These lessons take you from what radio actually is to your first weekend project.
- What is a software-defined radio? Learning SDR with a cheap USB dongle
- The radio spectrum, from DC to daylight
- Radio frequencies in Australia: Sydney, NSW and every capital city
- Watch free-to-air TV on your laptop, no login or subscription
- Nooelec NESDR SMArt v5: 12 weekend projects for one USB radio stick
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Classic tech, explained
How it actually works.
The fundamentals that don’t go out of date — how data is physically stored, how machines catch their own mistakes, how information moves, how an AI chooses its next word, how a compass needle finds north. Written for curious people and our clients alike: no jargon and no prerequisites. Some of this is decades old. That’s rather the point — it will still be true in twenty years.
- Connecting a Yamaha PSR-275 keyboard to a computer with the Roland UM-ONE mk2 — The PSR-275 has no USB, only 5-pin MIDI. Which UM-ONE plug goes where, the COMP/TAB switch, what the three lights mean, Local Control and the PC button, letting the computer play the Yamaha’s own sounds, and what to check when nothing plays.
- Learning electronics: a hands-on way to understand the digital world — Voltage, current and resistance, Ohm's law, resistors and their colour code, capacitors, LEDs, chips and pin 1, how voltages become the 1s and 0s of the digital world, and two first Arduino projects on a breadboard.
- What is GitHub, and how does it work? — Git remembers every version of a project; GitHub is where everyone’s copies meet. Seven diagrams take you through commits and their IDs, the staging area, branches and merging, pull requests, forks and clones, and how a small team can use it safely.
- Learning digital electronics with the Elegoo UNO R3 starter kit — What’s on the UNO R3 board, which of Elegoo’s three kits to buy (Basic, Super or Complete), how to set up the Arduino IDE in ten minutes, and ten experiments in order, each teaching one idea of digital electronics: outputs, inputs and pull-ups, binary, the shift register, PWM, analogue-to-digital, serial and timing.
- EEVblog BM786 user guide: every feature, and how and when to use it — Every dial position, button and hidden setting on the EEVblog BM786 multimeter: which socket the red lead goes in, step-by-step how-tos, and where each feature earns its keep, from AutoHold and REC to CREST, EF, VFD and nS.
- Our new multimeter: the EEVblog BM786, and the kit we bought with it — Why we bought an EEVblog BM786 for the workshop, what came in the box, the case and spare HRC fuses we added, what 60,000 counts, 0.03% and CAT III 1 kV / CAT IV 600 V actually mean, and our notes as we use it.
- How to test a battery with a multimeter (and when you need to put a load on it) — Red lead in V, black in COM, dial on DC volts. What the reading means for AA, 9 V, coin, lithium-ion, LiFePO4 and car batteries, why a battery that reads fine can still be worn out, and three ways to put a load on it.
- Storage media field guide: identify every old disc, tape, floppy and memory card — Decades of discs, tapes, floppies and memory cards, each drawn to scale beside a bank card with a photo of the real thing: how to tell it apart, what it holds, what can still read it, how it fails, and whether we can transfer it.
- Battery equivalents: every button, coin and household battery, and what else it’s called — Type the code off any battery and find every other name it goes by: LR44 = AG13 = 357, 377 = SR626, A23 = 23A. Coin, watch, hearing-aid, household, remote and camera batteries drawn to scale, the same-size lookalikes that must not go in, and Australian safety and recycling advice.
- The complete history of AI, from ancient myths to ChatGPT — People have imagined thinking machines for nearly 3,000 years. The whole story of AI in plain English: Talos and Ada Lovelace, Turing and Dartmouth, two AI winters, Deep Blue, AlphaGo, transformers and ChatGPT, and what it tells you about what comes next.
- The Turing machine: the 1936 idea behind every computer (and every AI) — In 1936 Alan Turing imagined a machine made of a paper tape and a short list of rules, and it describes every computer since. How it works, the universal machine, what Turing complete means, what no computer can ever do, and one you can run in your browser.
- Every screw in a PC and a laptop, and the driver that fits it — The two threads that hold a desktop together (6-32 and M3) and how to tell them apart, M.2, standoff, fan and radiator screws, laptop M2 and M2.5 screws and the screw map that saves them, and every drive from Phillips and JIS to Torx and pentalobe. With diagrams and reference tables.
- Computer to speakers: getting the best sound, and the traps along the way — Getting music from a Windows PC to your amp untouched: a USB-to-coax card into the amp's own DAC, or an external DAC. The traps we hit (Windows' mixer, a 96 kHz light that proves less than it seems, 24-bit becoming 16, no volume knob, bit-perfect songs that still clip) and a ten-minute check.
- Nooelec NESDR SMArt v5: 12 weekend projects for one USB radio stick — Twelve weekend projects for the Nooelec NESDR SMArt v5 RTL-SDR dongle: your own flight radar, ships in the harbour, the weather station next door, a weather balloon chase, a satellite photo, pictures from the ISS and shortwave. Frequencies, aerial lengths and free software for each.
- MCHammon: a free Hammond B3 on a Linux laptop, and the road to two manuals and a real Leslie — Our own B3 build: a Yamaha keyboard, a Roland UM-ONE and the free setBfree engine on a Linux laptop, with a front end we wrote. What works, what we fixed, and the plan for a second manual and a real Leslie.
- Reading a broken CD with a microscope: how forensic labs recover data from shattered discs — Snap a CD in half and about 99% of its data is still there. How a 3D laser scanning confocal microscope photographs the pits, how labs decode the pictures back into bytes, who has done it, and why it's still slow research rather than a service you can buy.
- What is a software-defined radio? Learning SDR with a cheap USB dongle — An under-$100 USB stick and free software turn your computer into a radio for almost anything: FM, DAB+, remote controls and TV. What SDR really does, how to set it up on Windows, Mac or Linux, and why the aerial's length matters (150 ÷ MHz).
- Watch free-to-air TV on your laptop, no login or subscription — The cheap SDR stick on your desk started life as a TV tuner. Plug in your TV antenna and watch live ABC, SBS, Seven, Nine and 10 on your laptop or iPad, with no app and no account. What we got on Linux, Mac and Windows, and the masthead-amplifier warning that saves the dongle.
- The radio spectrum, from DC to daylight — Your power point, the AM radio, your phone, the Wi-Fi, your TV remote and sunlight are the same thing at different speeds. Every band from 0 Hz to visible light, with the Australian uses in each and the facts on safety.
- Radio frequencies in Australia: Sydney, NSW and every capital city — Every frequency worth knowing, Sydney and NSW first, then every capital: CB and repeaters, marine, ham, FM, AM, DAB+, TV, aviation and emergency services. Each table sourced and dated.
- Can a damaged or unfinalised DVD be saved? — Usually, yes. The two different problems (physical damage, and discs that were never finalised), what not to try first, and the image-first rescue we use: GNU ddrescue under our own Linux program, with IsoBuster on Windows.
- Why a 24-bit file can quietly play as 16-bit — A 24-bit FLAC can lose its lowest 8 bits on the way to your speakers, and Windows won't tell you. What happened with our USB optical sound card, every place the bits can go, how to check, and whether it matters.
- HDMI ARC and eARC explained, plus every HDMI version and plug — How one HDMI cable sends a TV’s sound back to a soundbar, what eARC adds for lossless surround and Atmos, how CEC lets one remote run it all, and every HDMI version, cable grade and plug from 1.0 to 2.2. With a setup checklist.
- All about compasses: buy Magnetic South, set the declination, find your way — In Australia a compass has to be balanced for Magnetic South (Silva MS, Suunto SH), and from Brisbane to Melbourne its needle sits 11 to 13 degrees east of true north. What to buy, how adjustable declination works, Grandma’s Socks and My Green Apple, and four orienteering techniques.
- AI technical terms explained: top-p, top-k, temperature and the rest — Every AI setting with a strange name acts at one of six steps in the loop that writes an answer. What top-p, top-k, temperature, min-p, penalties, max tokens and seed each do, worked through on one example — and which services still let you change them.
- How AI works: why the same question gets a different answer — A chatbot works out the odds of every possible next word, then rolls weighted dice. The first half is deterministic; the second is not. Why a fully trained model still gives different answers to the same question — with diagrams.
- MKV, AVI and MP4: what a video container actually is — The three letters on the end of a video file name the box, not what’s in it. What a container does, how AVI and MKV are built inside, which codecs travel in each, and how to swap one box for another without losing a thing.
- All about codecs: how video and sound are squeezed into a file — An hour of raw standard-definition video is about 75 GB; a codec is why it fits in one or two. The four tricks every video codec uses, what I, P and B frames are, and a field guide to H.264, H.265, AV1, DivX and the rest.
- Why a copy-protected audio CD can’t be copied exactly — Some copy-protected CDs have wrong samples pressed into them on purpose, and rely on the player’s firmware to guess past each one. Why a copy of a guess can be neither exact nor verified — with diagrams.
- Interlaced video, and how deinterlacing undoes it — Every frame of old video is two half-pictures taken a fiftieth of a second apart. Why that was invented, why it puts comb teeth on anything that moves on a modern screen, and how weave, bob and Yadif put the picture back together.
- How to convert VHS tapes to digital yourself — If you still have a working VCR, the rest costs very little: a USB capture stick, free software and an evening per tape. The settings we use, the fix for the picture shape, and what the cheap route won’t do.
- How to convert cassette tapes to digital yourself — A USB cassette player, Audacity and one setting that matters more than all the others: the input level. How to record a tape without clipping it, why to keep FLAC, and what a cheap player won’t do.
- WAV, FLAC and MP3: what’s actually inside an audio file — WAV writes every measurement down as-is. FLAC stores the same measurements in about half the space, with nothing lost. MP3 keeps only what you’re likely to hear — so use it only when a player accepts nothing else. How each works, with real file sizes.
- Connector reference: every plug and port you’ll actually meet in Australia, with dimensions and photos — Every USB plug and port with sizes, speeds and power, a complete guide to USB versions, all five DVI types, Apple and iPod leads, RCA, BNC, antenna, SMA, RP-SMA, N-type, UHF (PL-259) and MCX, audio, network, drive, mains and DC power plugs — diagrams and photos, side by side.
- Which way does a VCR head drum spin? A correction to The Way Things Work — The Video Recorder page draws the head drum turning against the tape. It should turn with it. The correction, the evidence, and how to check any VCR diagram yourself.
- How a CD stores data: pits, lands, and the maths that survives a scratch — A five-kilometre spiral of microscopic bumps, read by a laser — and a layer of error-correcting maths clever enough that a fingerprint doesn’t matter.
- How a computer knows a file isn’t broken: parity, checksums, hashes and ECC — Bits flip — from worn flash cells, dodgy cables and cosmic rays. Here’s the ladder of tricks that spots the damage, and the ones that quietly repair it.
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This section is the timeless stuff — how the machinery works, underneath. For plain-English guides on decisions you have to make this year — AI at work, what Copilot, Claude and ChatGPT cost in Australia, domain pricing — head to the articles.