Comment by mikewarot
7 days ago
I've got a friend who has been at this since learning in TV repair shops in the 1950s. His emphasis is always on fast turn-around. He doesn't believe in slowly turning on things with old electrolytic capacitors, for example. I've learned quite a bit from him.
I've learned not to fear B+, but to give very healthy respect to anything more than 500 volts. (Only use 1 hand, keep the other behind you, always have a safety partner, etc)
I've learned to hate Silver Mica capacitors. I've learned how to track down the bad ones that cause the "crashing" sound in old radios.
I've learned that in very old electronics, you can let smoke out, and things will still work. I've gotten good at seeing where the smoke comes from.
You'll definitely need to learn to solder. I'd suggest starting with something like an Arduino starter kit to get a sense of how components actually interact.
But remember, if something is dead, you can't really make it worse. (Just be careful not to make yourself worse along the way)
> give very healthy respect to anything more than 500 volts
Man, I'd say be very respectful to anything that might be running 120-240V, and be very sure about anything higher than that. Anything <50V can often just be fun tinker whatever assuming you're ok with breaking whatever you're playing with, up to a certain max amperage of your power source. High amperage but low voltage can still cause some serious messups if you don't have the right fuses in place. But I get other voltages are common in Europe.
DC, definitely. Above 60V is dangerous.
AC, 120V will 'bite', 240V will make you shaky (remembers id10t maneuver yesterday, first in a decade). And burn you. In damp environments or with corrosion around, much worse things can happen.
i’ve been hit by 350V trying to bias a tube amp but it was low current (B+). Woke me up
Nah, 120v ain't so bad. Hurts less than hitting your finger with a hammer.
I'm not necessarily talking about getting shocked (which can still end up being bad), I'm also referring to the fact a lot of those 120V circuits are probably only protected by something like 12-15-20A of circuit breakers that might take a while to actually blow and unless you're in a kitchen or a bathroom or whatever probably don't have GFCI protection. Messing something up can quickly lead to quite a fire.
1 reply →
I would not want to touch 120V with wet hands, for example...
yeah I just treat any higher voltage like I would a snake, I stay away haha.
> You'll definitely need to learn to solder.
Probably implied here, but learning to desolder is huge too. And there are tricks to it that didn't come easily to me. When you buy your first iron, I think it's worth getting some flux and solder wick as well. Taking circuits apart cleanly and properly can make repairs so much easier.
Me the complete soldering newbie was very surprised when he discovered that desoldering is much more difficult than soldering. Getting a blob of tin to conduct is easy, getting the blob of tin out of there… impossible without tools and technique. Obvious in hindsight.
On that note, is it worth it to get a desoldering iron ? Like, what is essentially a soldering iron and a desoldering pump combined ? I've had little success desoldering in the past, and broke boards because of it.
Yes. If you can afford it (around 100 $€ will get you a basic one) and you expect to use it more than once, it'll save you a lot of grief.
Desoldering is one of those things where the right tool is almost mandatory.
Sure, you can desolder with a cigarette lighter and some luck, but you’ll be much happier with the iron.
Gosh, you don't need to start with dangerous high voltage tube stuff! There are old transistor electronic devices that was built on circuit boards with nice discrete components. You can practice soldering and unsoldering on an old transistor radio.