2026-01-19 01:21:41 <LispBot758  > Chargé 7 commande(s)
2026-01-19 01:48:35 <KipIngram   > tpbsd: When you need matched transistors do you just go through a batch by hand to find a pair that work well together?
2026-01-19 01:48:48 <KipIngram   > Or is it usually just good enough for your cases?
2026-01-19 01:49:29 <tpbsd       > KipIngram, Ive never bothered to match them
2026-01-19 01:49:58 <KipIngram   > I haven't done any audio either, really.  It would be a new experience for me.  I do have an old 1938 radio that belonged to my wife's grandparents - a big floor standing tube based thing - that I intend to restore at some point.  But that's of course not a particularly high fidelity application.
2026-01-19 01:50:49 <KipIngram   > My garage workshop is a mess right now, though - I need to do some serious tidying up on it to get myself some reasonable working space again.
2026-01-19 01:50:50 <tpbsd       > KipIngram, I just use them found in my stock. these days transistors of the same type, purchased in the same lot are very similar
2026-01-19 01:51:21 <KipIngram   > You know, that makes sense - I've probably just read some pretty old books.
2026-01-19 01:51:27 <tpbsd       > same here, my workshop is a mess right now
2026-01-19 01:51:37 <KipIngram   > It does make sense that processes would have gotten more repeatable over time.
2026-01-19 01:52:16 <tpbsd       > if I was making a precision op-amp with BJT's I may possibly categorise them by Hfe
2026-01-19 01:52:47 <tpbsd       > I have the gear to easily do that, but for audio preamp op-amps, I didnt need it
2026-01-19 01:53:59 <tpbsd       > heh, the amp was part of my conversion of valve powered 'watch timing machines' to solid state
2026-01-19 01:55:02 <tpbsd       > at the later stage of the mechanical watch industry, watchmakers were still everywhere and they all had these once very expensive Swiss or Japanese 'watch timers/counters
2026-01-19 01:56:19 <tpbsd       > the first time I was asked to repair one I knew they had to be converted, and that buisness alone kept me going for a few years
2026-01-19 01:57:23 <tpbsd       > the engineering to make a watch timer using only a few valves was amazing, I have so much respect for the EE's of those days
2026-01-19 01:57:51 <KipIngram   > I've never done any tube work either, so that would also be new.  I was able to find schematics for it online, though; it's a fairly straightforward superhet design.  The real challenge will probably be fixing all the mechanicals (there are a bunch of pulleys and cable for the tuning, and there's a push-button preset mechanism that's basically shot, and I expect that to be a fair challenge).
2026-01-19 01:58:01 <KipIngram   > If I can manage it at all.
2026-01-19 01:58:54 <tpbsd       > I grew up with valves, so that part was no problem for me
2026-01-19 01:59:14 <KipIngram   > I'm not going to try to find "proper" replacements for the original wire - it used that old fashioned fabric covered stuff, and all the fabric has rotted.
2026-01-19 01:59:16 <tpbsd       > the problem was that the valves weren't available any more
2026-01-19 01:59:37 <tpbsd       > KipIngram, her is my tip for you
2026-01-19 01:59:39 <KipIngram   > So far as I checked I saw all the ones I'll need at Viva Tubes.
2026-01-19 01:59:48 <tpbsd       > make that wire
2026-01-19 01:59:56 <KipIngram   > Really?
2026-01-19 02:00:03 <tpbsd       > absolutely
2026-01-19 02:00:11 <KipIngram   > Why do you suggest that?  Just for better authenticity?
2026-01-19 02:00:13 <tpbsd       > get some 'builders string'
2026-01-19 02:00:47 <tpbsd       > it's available at hardware stores, it's basically high quality twine, probably cotton based
2026-01-19 02:01:02 <tpbsd       > and get a small pot of Latex rubber
2026-01-19 02:01:13 <tpbsd       > thats easily available also
2026-01-19 02:01:15 <KipIngram   > Wrap the wire with it?
2026-01-19 02:01:47 <tpbsd       > just put a length of the twine in the latex pot and then take it out and hang to dry
2026-01-19 02:02:18 <tpbsd       > Ive done exactly that for motor carriage drive cables, it's supurb
2026-01-19 02:02:29 <tpbsd       > grippy, strong nd very long lasting
2026-01-19 02:03:15 <tpbsd       > I was shown the method by a skilled designer 40 years ago
2026-01-19 02:04:25 <KipIngram   > Hmmm.  I will look into it.
2026-01-19 02:04:34 <tpbsd       > you wont regret it
2026-01-19 02:05:06 <tpbsd       > the only weakness is that latex degrades in the sunlight
2026-01-19 02:05:25 <tpbsd       > but thats not usually a problem in such applications
2026-01-19 02:05:47 <tpbsd       > latex rubber from trees
2026-01-19 02:06:54 <tpbsd       > I wouldnt hesitate to use it for small nc tables as in 3d printers , plotters wtc
2026-01-19 02:06:56 <tpbsd       > etc
2026-01-19 16:57:32 <KipIngram   > You almost make it sound like it's superior to COTS wire in some way.  Are you just liking the idea of "higher authenticity," or is there some actual advantage it has over COTS?
2026-01-19 16:58:39 <KipIngram   > I also like authenticity - more is better - but am also a little sensitive to not excessively magnifying my labor.
2026-01-19 17:01:20 <KipIngram   > I've never been the word's best at this hands-on stuff.  A couple of summers ago we had a lightning bolt hit our house, and among the things it killed was our pool system control board.  I had a guy out to quote fixing it, but all he wanted to do was sell me a brand new $3,000+ system.  I told him thank you I'd think about it and then forgot about him - I made one around a Raspberry Pi.  Hand
2026-01-19 17:01:23 <KipIngram   > wiring - I didn't do a PCB, though I have since then and need to test it at some point.  Anyway, that hand built one is installed and has worked fine for going on two years now, but it's sure nothing pretty to look at.
2026-01-19 17:01:45 <KipIngram   > Thankfully, all that is hidden behind the front panel, but I still know it's there.
2026-01-19 17:01:53 <KipIngram   > The PCB is quite nice, though.  :-)
2026-01-19 17:02:53 <KipIngram   > On-board lightning protection and everything, though you can never count on that sort of thing 100%.
2026-01-19 17:03:58 <KipIngram   > Nice separation between the AC and DC sections, with guard traces, hot 120V confined to internal layers, etc.  You'd have to touch the actual pins of the AC components to get shocked.
2026-01-19 17:04:46 <KipIngram   > And I could probably use some kind of spray to prevent even that, though I probably won't bother.   The silkscreen has clear warnings in that vicinity.
2026-01-19 17:05:34 <KipIngram   > I was conscious of the fact that someone else might own the house someday.
2026-01-19 17:06:27 <KipIngram   > If we do decide to sell I'd probably want to finish out validating the PCB-based controller and swap it in.
2026-01-19 17:08:16 <KipIngram   > I put LEDs on it that should let me almost completely confirm it's operation without it installed.  I could actually run the scheduling software and watch the LEDs tell me what it's doing at any given time.
2026-01-19 17:08:55 <KipIngram   > The whole thing cost about $250.  I liked that a lot better than $3k+.
2026-01-19 17:09:17 <KipIngram   > I still haven't written a web interface for it, though - I really do need to get that done.
2026-01-19 17:09:52 <KipIngram   > I can run it via ssh - it's basically driven by writing to a collection of files.
2026-01-19 17:10:40 <KipIngram   > I tried pretty hard to use the file system as a clean separation between the electrical control and the higher control logic.
2026-01-19 17:11:08 <veltas      > Wow, never had to deal with lightning strike in my home
2026-01-19 17:11:42 <KipIngram   > Ugh - I truly hope you never do.  You see the major damage immediately, but then can just keep on finding little oddball things that no longer work for like weeks.
2026-01-19 17:11:58 <KipIngram   > It hit one of the venilation pipes sticking up through the roof from the AC system.
2026-01-19 17:12:18 <KipIngram   > That pipe had a little "hat" on it to keep rain out - it blew that completely off and we found it lying in the side yard.
2026-01-19 17:12:49 <KipIngram   > Killed the control electronics in both upstairs and downstairs AC systems, and it was Houston summer, so that had to be dealt with right away.
2026-01-19 17:12:57 <KipIngram   > I did have to open my wallet for that.
2026-01-19 17:14:10 <KipIngram   > The rest of it I managed largely on my own.  The pool was the big one, but I also had to replace one of the garage door openers, the "smart" board in our alarm system (I was lucky enough to find that one on eBay), and a whole bunch of "wall wart" units here and there around the house.
2026-01-19 17:14:41 <KipIngram   > Oh, and I had to call AT&T out to replace parts of our internet interface stuff.
2026-01-19 17:15:12 <KipIngram   > So yeah, if it happens, then there's really just no telling where all it finds its way to.  It's a mess.
2026-01-19 17:15:32 <KipIngram   > I used to kind of enjoy thunderstorms, but now I get nervous every time one gets close.
2026-01-19 17:16:24 <KipIngram   > Gave thought to a lightning rod, but that involves the HOA so I've never gotten around to it.
2026-01-19 17:17:56 <KipIngram   > I imagine most people would interpret it as a ham radio antenna, and those just automatically stick in HOA craws, so it feels like an uphill climb.
2026-01-19 17:19:51 <KipIngram   > Mostly it was just that everything other than the AC could wait some reasonable period of time while I figured out how to deal with it.
2026-01-19 17:21:01 <KipIngram   > I will note that in the pool system none of the heavy stuff (the big motor relays and so on on) was hurt at all.  Only the low-voltage stuff.  That helped - the part that died was the part most "up my alley."
2026-01-19 17:23:20 <KipIngram   > Mostly just turning those big relays on and off, which just took one little transistor circuit for each.  The pool/spa mode selection does require switch a 24V AC waveform, so there's a relay on there for that, and those valves know how to stop turning on their own, so other than just switching that relay nothing further was required.
2026-01-19 17:24:12 <KipIngram   > Those valves have three control wires, +, -, and common.  Put 24VAC across +/common and they go one way - put it on -/common and they go the other way.  Pretty simple.