LED Tom

One of these things is not like the other… The other day @PratapRanade brought home 3 RF circuits. Ok “10GHz band pass-filters” he says, to be precise. The first two are human-made, the third is what they’re calling “an alien geometry” 👾 Look how funky it is. That’s the world’s first-ever AI-made RF circuit achieved by the electromagnetism foundation model @arenaphysica. No human would have created it this way. It’s odd, it looks random, but it really works & it might be the future guts inside every satellite, radar, microwave etc one day.

Transient Absorption (TrA) Spectroscopy at the University of Auckland’s Photon Factory captures ultrafast molecular changes post-light excitation using femtosecond pump-probe lasers. 14 years old

Been working on something I've wanted to build for years — a radio imaging array. The concept: take an array of antennas, digitize every element with a phase-coherent SDR, then cross-correlate all baseline pairs to synthesize an aperture and image the radio sky. Same interferometric principle behind the LWA-TV system at the Long Wavelength Array in New Mexico (leo.phys.unm.edu/~lwa/lwatv.html), which runs 256 dual-polarization antennas doing real-time all-sky imaging below 88 MHz. My version operates at 420-450 MHz. The antenna array is a 4x4 grid of circular cross-dipoles with ~0.6λ spacing. Each element feeds a home brew multi-channel FPGA SDR with 10GbE backhaul. All channels share a common 10 MHz reference and PPS, keeping the digitizers phase-locked across the array. The software aligns the incoming VITA 49 (VRT) streams by timestamp, computes the cross-power spectrum on every antenna pair, and builds a dirty map from the visibility matrix. Beyond imaging, the same hardware opens up some other things I want to explore — angle of arrival estimation on HF, adaptive beamforming, and real-time interference cancellation by nulling specific spatial directions. An array that can see the full sky can also choose what not to see. Only running 4 elements right now so the PSF is wide and the sidelobes are ugly, but the coherency holds through frequency changes, the correlation display updates live, and the sky map shows structure. Once the full 4x4 is wired up — 120 baselines, ~8° resolution at 435 MHz — it should start to get interesting. And there's nothing stopping it from scaling further. Drift scans can fill in the uv-plane over time and improve image quality from fewer antennas. Images below: 4 coherent channels streaming live with sky correlation display The 4x4 circular cross-dipole array for 435 MHz For inspiration — the 256-element LWA array doing this at HF (LWA-TV live)

啥叫同频转速！为什么没撞上，这是说明伺服电机厉害，还是说丝杠精密度很高呢？

@BrianRoemmele Absolutely love this! Veritasium opened my eyes to analog compute methods for tide timetables 4 years ago. Well worth an analog watch ! youtu.be/IgF3OX8nT0w?si…

My project for the afternoon: Gentle disassembly and scanning for YOUR AI project. But why? Current AI has lost knowledge of analog circuits and I am fixing this. These books were donated after being seen at an antique dealer, they sent it to me to do just this. But some very fine folks in AI, brilliant folks think I am insane. What they don’t yet understand is in these analog vacuum tube schematics are lost modern knowledge of analog math. Analog math (voltage, amps) operates nearly at the speed of light. AI uses this math in just about all ways and today 80% of the time and 90% of the energy is expended doing this math. None of these circuits have EVER been digitized. And your standard “AI training) folk like Reddit over the logic of schematics. Thusly I get 2 for 1 here. Not only do I get to build on AI’s ability to recover lost modern knowledge (not to fix TVs, but who knows) but also to encase in to AI models the logic of an analog designer. THAT LOGIC CHANGES HOW AI “THINKS” AND CREATES. So decades from now when the average person knows this as an axiom know that you and folks like you were awake and aware to save what others thought was a bunch of dusty old TV Repair Manuals from products long gone, but saw something of value. The value is even higher than I know right now. To those in this journey, thank you, deep gratitude. We are doing this not them.

@thinkdefence Thankfully, we still have @RAF_LUTON for when it all goes tits up!

Ed Miliband gets relentless bile from the right for his ‘ideological’ commitment to clean, cheap renewable energy - just as Nye Bevan once did for creating the NHS. Yet on March 25 97.7 % of our electricity was from renewables. A revolution is unfolding. observer.co.uk/news/columnist…

It’s that time of year - folks asking us about #bumblebees - WHY THEY’RE SEEING THEM ON THE GROUND - so here’s a thread to explain. Please #retweet! Every queen that survives means a new colony that gets to exist & produce queen #bees for next year! So important to #share! 1/9

#FreeCAD v1.1 has been released!!! Thx to everyone that worked, tested, triaged, donated etc. to make this happen! Spread the word, RT please 🙏 Announcement: blog.freecad.org/2026/03/25/fre… Release Notes: wiki.freecad.org/Release_notes_… youtu.be/a9biWv_M8p8 #FLOSS #FOSS #3DCAD #CAD #CAM #FEM

This is absolutely astounding! A printer that prints circuit board traces. I am going all in on this. We will have a 100x increase in production and testing!

@terhyc STOCK

Decoding Morse Code.

Here are the apogees and perigees of VAP A and B over time

1937 MotorGraph Sign. Spectacular technology.

@BrianRoemmele Thank you Brian. As a 2026 LED screen engineer, you have just completed a whole chapter of my career history that I was COMPLETELY unaware of. Subtle observation: regular font converted to italic font on the display ? Genius !

I’m a chemist. I need to say this - because it’s getting dangerous out there. The biggest health myth in the world isn’t about vaccines. Or GMOs. Or fluoride. It’s the root of all of them. It’s called chemophobia - and it’s killing science. Fear of “chemicals” now drives vaccine rejection, GMO bans, food hysteria, and entire political movements. From tampons to tap water, people have been taught to fear chemistry - the very thing that keeps us alive. Chemophobia tells us: “Natural is good.” “Synthetic is bad.” That’s a lie. Botulinum toxin is 100% natural and one of the deadliest molecules known. Aspirin is synthetic and life-saving. We’ve gone from banning harmful substances for good reason…to banning safe, well-tested molecules for emotional reasons. You’ve seen the slogans: “If you can’t pronounce it, don’t eat it.” “Paraben-free.” “Clean beauty.” They sound empowering. But they’re not science - they’re marketing. And they’re making the world dumber, poorer, and sicker. Your body doesn’t care if a molecule comes from a plant or a lab. Vitamin C is vitamin C. Formaldehyde is formaldehyde and your body makes more of it every day than any vaccine ever could. Dose matters. Source doesn’t. This fear isn’t harmless. It shapes public policy. It blocks innovation. It raises food prices. It slows down cancer treatments. Chemophobia is now mainstream and it’s costing lives. Scientists aren’t losing because we’re wrong. We’re losing because fear spreads faster than facts. Because influencers sell fear for clicks. Because lawyers monetize doubt. And because scientists are too tired to fight back. So here’s my message, as a chemist and as a citizen: Learn how toxicology works. Call out chemical fear-mongering. Support policies based on evidence, not emotion. Chemistry isn’t the enemy. It’s the reason you have clean water, safe food, and modern medicine. If we let fear win, we lose all of it.

You're in for a real treat soon. I just had Alex Lidow from EPC on the Amp Hour in video. Alex invented the power mosfet, the HEXFET, and GaN technology, and was the CEO of International Rectifier (founded by his father). We talked history, semiconductor physics, GaN, AI, and a whole bunch of stuff.

A new repair resource website. A community-driven database for electronic components, schematics, and repair documentation. junkbin.io