Oscillator Valves Etc. Triggering ??? - Page 1
Forum section: electronics / general

author: GlennSprigg
author_rank: Super Contributor
timestamp: April 06, 2020, 02:03:29 pm
content: I don't knowWHYI keep punishing my 'brain' when my time is limited?? Sigh...It seems to just 'snowball' when reviewing certain topics, and I can't stop!!...Yet another "Mr Carlson's Lab" equipment test, where half way through, he was talking about a previous post, about certain pieces of equipment that had a simpleLight-Globehidden under the Chassis in close proximity to certain Valves. I'm sure experts here will know, but it is to do with exciting the circuit, to result in controlled oscillation. Some devices/parts/components utilizedRadioActiveinternal additions for this purpose, but having a half-life of about 5 years, this would have rendered such valves etc useless now. So adding a physical light-source adjacent to it, would result in the continued usefulness of such a circuit today...THIS video is/was about 'firing-up' an old X/Y scope device. However, look at16:21to22:15to see what I am talking about...Although fascinating, & beyond what I ever learnt before, I need to scale back the 'snowball' effect !I don't even know why I'm totally rebuilding my workbench, & power-supplies etc. I think I just don't want to loose the part of my 'mind' that used to give me so much joy. It's like if I lose that then I have nothing left? I'm now just 're-inventing' old simple resonant circuits and playing with oddball components to keep my 'brain' active, and pass on what I know to certain friends/family...

author: vk6zgo
author_rank: Super Contributor
timestamp: April 07, 2020, 12:58:11 am
content: Interesting!Funny thing is, I've never run into the practice over many years in the business.Mostly, if gas tubes played up,you just replaced them, & apart from regulators & the odd Thyratron from time to time, they weren't a big part of my experience.Most equipment after the early '50s employed "hard timebases", using normal vacuum tubes.I have certainly seen equipment with incandescent lamps inside, but they were mostly to control the feedback on Wien bridge oscillators, so as to stabilise the output level.Here are some other "funnies":-(1)How did the flashcubes that didn't use a battery supply work? (I do know this one, it is on line)(2)Here is the really weird one!Many years ago, at my work, we had made up a bunch of small Mains distribution panels which were to be fitted at the base of equipment racks.Someone realised that 120v neon indicators (in rectangular plastic mouldings), had been fitted by mistake.We were told to remove them, destroy them & replace them with 240v ones, so a bunch of us sat there, removing them.Somebody suggested a good way to destroy them would be to fling them at the concrete floor.On doing this, we discovered that on impact, the neons would briefly flash, so we had a lot of harmless funmaking this happen.The impact definitely destroyed them, as trying again with one that had already hit the floor produced no flash.

author: GlennSprigg
author_rank: Super Contributor
timestamp: April 10, 2020, 12:20:02 pm
content: Quote from: vk6zgo on April 07, 2020, 12:58:11 amWow...vk6zgo... you really helped my scaling back the 'snowball' effect of my desire to learn!!I found the following, about old FlashCubes/MagiCubes...https://www.lightstalking.com/flashcubes/The 'younguns' here probably have never even seen or heard of them!RE: theNeons... I've not looked it up, but I would 'imagine' the shattering Glass might create a high voltage, something like the hammer on a crystal inside a cigarette lighter or stove-top lighter?? Seems feasible to my slowly retarding brain!!

author: Cyberdragon
author_rank: Super Contributor
timestamp: April 10, 2020, 03:20:06 pm
content: I've seen a NIB flashcube camera in a antique store once with all the original bulbs and spare cubes in boxes thrown into the case (IDK if there was extra film too, but it looked as if someone bought a camera and supplies back in the day then forgot about it).