Signetics announced the NE555 timer/oscillator IC in 1972, 50 years ago. Over five decades, this simple 8-pin chip has consistently sold in the billions, each year. It’s a perennial hobbyist favori…
I live just a few miles from KNX-1070, a 50 kW AM radio station in Los Angeles. It's hard to NOT pick up a news broadcast on anything with an audio amp & speaker, which rectifies and detects any suitable signal. Our church is less than a mile away. I teach robotics classes there occasionally to kids, and I have started collecting parts for my next class, making a crystal radio. I'm sure a short antenna is all that will be required, just a few feet of wire, or maybe a SPOON.
Potentailly capacitively coupled to a hundreds of feet/meters of aerial telephone wiring would provide a large capture surface for radio waves of all types ;-)ah yes ... I remember seeing suggestions that a connection to the metal finger stop on a dial telephone, made a good short-wave aerial.
this reminds me of the vacuum tube 555Want! Just not ready to drop $35. https://shop.evilmadscientist.com/productsmenu/tinykitlist/652
View attachment 25160
BTW that has been around for a decade but now there's a surface mount edition too. https://shop.evilmadscientist.com/productsmenu/922#
View attachment 25161
Good news: It's true, that's a great antenna.ah yes ... I remember seeing suggestions that a connection to the metal finger stop on a dial telephone, made a good short-wave aerial.
I have never played with valves but a great video of someone making a 555 with them really great thanks for sharing it.this reminds me of the vacuum tube 555
Building the Largest 555 Timer in the World out of Vacuum Tubes - YouTube
What? You missed all the fun of drilling a steel chassis so you could use the hole punches for the different size tube sockets? We all sympathize with your deprived childhood ;-)I have never played with valves but a great video of someone making a 555 with them really great thanks for sharing it.
Yep great place i have been a few times over the years, didn't know he was still open, i bought a 20A variac from there had to walk across lincoln carring 20kg of variacWe still have John Birkett's in Lincoln. A genuine treasure trove. Some walls were lined floor to ceiling with valves (tubes?). I once asked to an obscure valve with a low voltage heater for a portable radio. "I've not got one here, but I've got one. Come back in a few days." I went back and not only had he got the valve (new old stock) but he remembered me, and could tell me what the valve was and what it was used for (IF amp, oscillator and mixer).
Opened in 1960 and still open a few hours a week. John has to be 80+ years old so perhaps we should be respectful and grateful that he opens at all.View attachment 25177
I bought from HSC online - even found the solid state "guts" of a 400 watt, 12VDC to 120VAC inverter (in the original factory packaging) for a few dollars. The design of the original inverter package was such that you coiuld add a second inverter board and make the 400 watt inverter into a 750 watt inverter. All modified sine wave but the price was right ;-)We had a place called Halted Solutions in San Jose. It had been there so long that Steve Jobs bought surplus parts to make one of the early Apple prototypes! Flip through the photos on Yelp - it was an amazing place: