Miguel A. Vallejo (EA4EOZ)

The 10-hour blackout in Spain confirmed that switching power supplies have destroyed amateur radio. 10 hours of noise-free bands and extremely weak signals with crystal-clear audio. Just incredible! But everything went to hell when the power came back on.

@drizzt__dourden Te falta un int 0x10 pero sí, muchos aun recordamos esa secuencia ;-)

Tengo más años que la tana capítulo ... Como he olvidado todo esto. Casi 30 años de ese código. push ax push bx mov ax,0x1201 mov bl,0x31 mov ah,00 mov al,0x13 int 0x10 pop bx pop ax

He. El Gimp todavía es capaz de abrir ficheros pcx :P

@AndreiBulu 1/16A, or 62.5mA

@ea4eoz Power loss = 82*16A*16A. Not a biggie. Only 20kW.

For some reason this 1/16A 250V fuse consists of a small 82 ohms resistor and a spring.

@B_foolish Maybe

@ea4eoz Slow blow fuse?

Retrocomputing still strong #retroparla2026

The ability to generate this image is the culmination of 3 years of work. 🤣

@beepfixer @RetroNora7734 @wasteeandglory Yes, the original software can check almost any TTL and 4000 series CMOS

@RetroNora7734 @wasteeandglory @ea4eoz scratches head.. you can run actual tests on TTLs using a programmer? wait.. what is this magic, and does it work on a TL866a ?

It seems that we've been betrayed by our own.

@PA9X I feel your pain... they also don't like being mailed.

Ferrite toroids are not elastic. They won't bounce back when dropped on a concrete floor. They will actually become double letter C. The C's in concrete...

@eb4fbz @maIavuranza @matseng Those ICs from the 70s are slow as hell, with very slow rise and fall times, that's why it's decoupling requirements are so low compared with our modern standards

@maIavuranza @ea4eoz @matseng Signal integrity is independent of frequency. It’s the edge rate what matters.

This reminds me of how much "bad engineering" and "ignoring of best practices" a design can tolerate and still work just fine. Like the KIM-1 - a single decoupling capacitor for 8 RAMs, CPU and I/O ICs. And the crystal super far from the oscillator in the CPU.

@cqcqcqdx So tired of AI crap...

Extracts information from radio signals via SDR devices github.com/BatchDrake/Sig…

@bml_khubbard 512kb in the 70s would have been something like infinite memory. I would have used those pins for extra IRQs.

I often wonder, what if the original 6502 in the Apple // had had 19 address pins ( 512KB ) instead of just 16 ( 64KB ). Those 3 NCs bother me to this day.

@bml_khubbard @mov_axbx That's what the PC ATX12VO standard aims to do.

@mov_axbx Here's a thought - what if the power supply delivered +48V DC and the motherboard did the rest?

I dream of a world where all modular power supply cables are compatible

@tercio_miranda All TVs supports rgb at 15kHz, but not all monitors supports rgb at 15kHz

Another $10bucks bargain! This TV supports rgb 15khz😜

@HB9VQQ Meshcore. It's great to see nodes hundreds of kilometers apart on Meshtastic, but messaging is a hit or a miss... far more misses than hits, so it's pretty useless. For messaging Meshcore just works

Meshcore or Meshtastic and why?

@circuitbasics 220 pF

Each RCA input terminal has a 220 uF C0G/NP0 capacitor soldered across the ground and positive signal terminals to filter out radio frequency interference before it gets inside the chassis. circuitbasics.com/how-to-build-a… #diyaudio #audiophile #hifi #diyelectronics

@gomezjl Cope y Onda cero

@ea4eoz Subsisten emisoras privadas?

This is the shutdown of RNE's 585 and 657 kHz transmitters in Madrid today. You can see the band is being abandoned because Europe failed to enforce its own EMC regulations. Switching power supplies powered devices are slowly killing radio