James Chessman gave me permission to use his comment. “””I have encountered a phenomenon called “age-down” in ceramic capacitors tested on ICT (In-Circuit Test) machines. I was working for a circuit-board manufacturer, developing new test sets. I was seeing these caps consistently read high in new tests. And, pulling them out of the circuit they
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Chuck commented about the audio oscillator being a BFO, and it reminded me that I’ve got an old RCA BFO audio oscillator stuck away in the garage. It was a cheap way of getting an audio sine wave that covered the full audio band without any switching. Nowadays it’s all done in sine and other
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He uses my SJT circuit in his web page. https://devopedia.org/joule-thief-circuit
Here is a wealth of information about much of the electronics that is used by government entities especially the military. You can find out what the system is for data processing hardware. This used to be called JAN – Joint Army Navy. https://en.m.wikipedia.org/wiki/Joint_Electronics_Type_Designation_System
I’ve been discussing the restoration of a hundred y.o. radio, and I thought about the retro light bulbs that look like incandescents but use LED filaments. Someone should make some old tubes that are actually using LEDs that look like the filaments, but just for decorative purposes. The glass envelope would look like the tube;
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I posted the photo of the back side of the receiver (earpiece) for a Bell System telephone (either 500 or 2500) set. I said that the green blob in my photo (and the ’44A’ metal can in the wikimedia photo below) was used for reducing the volume of loud signals. Well, that’s only slightly correct.
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Mars 2020 Rover AKA Perseverance in High Resolution and detailed. Full Resolution link ( No Facebook Compress ) below https://d2pn8kiwq2w21t.cloudfront.net/original_images/jpegPIA23312.jpg Excellent closeup image. It looks like 10 or mor kg of Kapton tape wrapped around the cables. But the worker is putting in red and blue cables that are not covered in Kapton. So it
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I found a way to make a 0.05 ohm resistor. I found some 0.1 ohm, 10W resistors and two of those in parallel will make 0.05 ohms. Voilá. The 10W is only if these 1 inch long resistors are bolted to a heatsink, so I guess they might handle 5 Watts free air. BTW, these
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Something that beginners can put on their desktop. http://nonlinear.eecs.berkeley.edu/chaos/ResistanceCalculator/resistor.htm
