$161 oscilloscope

> Chemicals? I build some thing that increased pressure in some can, and put it under the teahers desk, the lid went boom after a while. 
> The danger was not much in the boom but in me being kicked out of school... 

You just reminded me of one of mine. I thought it would be so cool and 
impress my 7th grade science teacher, Mr Ragle, by bringing in a
big bottle of hydrogen. I just read about electrolysis of water (I used an 
electric train DC power supply -- that had a 'smelly' Selenium plate dual-diode;
and carbon rods from "D" cells).  He was cool as a cuke, "that's nice", & gave it
 not much concern. You see, the bottle was plastic (shampoo), sealed with a 
work & some wax. So unbeknownst to me, the danger leaked out way before 
I even got to school. He was kind & didnt "leak" this information to me, though. 
  

> work & some wax. So unbeknownst to me, the danger leaked out way before 
* CORK

> Kids are so much more protected now, and so much more afraid.

well to be fair, some parents (mine) had no clue
we were doing these risky things in the basement...
(not that it would've made much difference, in
my case). Although, once I blew out a fuse, & darkened
some rooms (shorting out the AC line - I though carbon 
had more resistance than that...), that get their 
attention.

On Monday, 20 December 2021 at 05:35:31 UTC, Spehro Pefhany wrote:
> On Sun, 19 Dec 2021 16:18:54 -0500, Phil Hobbs
> <pcdhSpamM...@electrooptical.net> wrote: 
> 
> >Jan Panteltje wrote: 
> >> On a sunny day (Sat, 18 Dec 2021 14:27:17 -0800) it happened 
> >> jla...@highlandsniptechnology.com wrote in 
> >> <srnsrglr1qa6arpsb...@4ax.com>: 
> >> 
> >>> On Sat, 18 Dec 2021 16:28:08 -0500, Phil Hobbs 
> >>> <pcdhSpamM...@electrooptical.net> wrote: 
> >>> 
> >>>> jla...@highlandsniptechnology.com wrote: 
> >>>>> On Sat, 18 Dec 2021 08:27:49 -0500, Phil Hobbs 
> >>>>> <pcdhSpamM...@electrooptical.net> wrote: 
> >>>>> 
> >>>>>> Rich S wrote: 
> >>>>>>> On Friday, December 17, 2021 at 10:54:41 PM UTC, John Larkin wrote: 
> >>>>>>>> On Fri, 17 Dec 2021 16:32:48 -0500, Phil Hobbs 
> >>>>>>>> <pcdhSpamM...@electrooptical.net> wrote: 
> >>>>>>>> 
> >>>>>>>>> John Larkin wrote: 
> >>>>>>>>>> I was looking for something else and this showed up: 
> >>>>>>>>>> 
> >>>>>>>>>> https://www.amazon.com/s?k=0751300436685&crid=21WX22FGW2XXG&sprefix=0751300436685%2Caps%2C262&ref=nb_sb_noss 
> >>>>>>>>>> 
> >>>>>>>>>> Amazing. Someone could set up a garage lab and do some serious stuff 
> >>>>>>>>>> really cheap these days. 
> >>>>>>>>>> 
> >>>>>>>>>> 
> >>>>>>>>>> 
> >>>>>>>>>> 
> >>>>>>>>> Potentially pretty useful, especially in a tool bag. 
> >>>>>>>>> 
> >>>>>>>>> Cheers 
> >>>>>>>>> 
> >>>>>>>>> Phil Hobbs 
> >>>>>>>> I could keep one at home. Or in my car. 
> >>>>>>>> -- 
> >>>>>>>> 
> >>>>>>>> If a man will begin with certainties, he shall end with doubts, 
> >>>>>>>> but if he will be content to begin with doubts he shall end in certainties. 
> >>>>>>>> Francis Bacon 
> >>>>>>> 
> >>>>>>> "Debugging Weapon" 
> >>>>>>> finally, Amazon is selling weapons. 
> >>>>>>> Kill those lousy oscillations. 
> >>>>>>> 
> >>>>>> 
> >>>>>> Not with a 100 MHz scope! I did see one at 38 MHz a couple of months 
> >>>>>> ago, but it's more usually 300 MHz or above. (My current record is 14 
> >>>>>> GHz iirc.) It's pretty cool to be able to get magic 60 GHz transistors 
> >>>>>> for 20 cents. 
> >>>>>> 
> >>>>>> I remember designing 70-MHz crystal oscillators with 2N5179s back in the 
> >>>>>> day, because 2N3904s were slightly too slow. (Yikes, that was 40 years 
> >>>>>> ago!) 
> >>>>>> 
> >>>>>> Cheers 
> >>>>>> 
> >>>>>> Phil Hobbs 
> >>>>> 
> >>>>> In my mis-spent youth I designed an RC emitter follower + 7414 schmitt 
> >>>>> gate as a system power-on reset. The 2N2219 oscillated so hard at 100 
> >>>>> MHz it never got the gate input high. 
> >>>>> 
> >>>>> Transistors are so much better now! 
> >>>> 
> >>>> Of course a CK722 would probably have worked too. ;) 
> >>> 
> >>> No, I needed an NPN. 
> >>> 
> >>> But CK722 was my first transistor. It cost $7, a couple of months' 
> >>> allowance. 
> >>> 
> >>> https://www.dropbox.com/s/wuv7xjd5jg1i3lx/Ck722-0A.JPG?raw=1 
> >> 
> >> My first transistor was the OC13 (Philips) Ge PNP 10mA LF 
> >> https://www.radiomuseum.org/tubes/tube_oc13.html 
> >> 
> > 
> >I think the first one I bought was a TR01-C, a TO3-packaged germanium 
> >made by IR. (I think it was germanium, anyway, but I was 11 years old, 
> >so I don't suppose I had any idea of the distinction.) I haven't been 
> >able to pull up a datasheet on it. 
> > 
> >Cheers 
> > 
> >Phil Hobbs
> NTE calls this an equivalent - probably close enough: 
> https://weisd.com/uploads/product/sheet_pdf/3758/NTE121.pdf 
> 
> ft of 300kHz .. it's hard to be worse than a 2N3055 but that does it. 

The early power geraniums were much worse. I guess it's hard to move back & forth under the weight of all those stems.