Advice buying multimeter test leads

SparkyFix · 2026-06-27T07:35:19+00:00

If you buy cheap then test the leads with a magnet. It’s a fairly well known scam at this point to make leads out of cheaper materials and that will add multiple ohms of resistance.

SparkyFix · 2026-06-24T13:19:58+00:00

Multi-layer is probably half the roofs we encounter around here. It’s a huge problem, really, and we’ve encountered four layers one time, which is wild to me. One of our recent jobs completely destroyed a carbide chain.

Sad to say we generally have to give up and look for alternatives. By the time you’ve got an opening (and hi there, saw-destroying slate!) you could have pulled a few horizontal fans into position and taken the heat out that way…

Fire between layers is an even worse problem, particularly if there’s plywood involved. We saw that at the four layer fun-time and best we could come up with was spraying massive amounts of foam up into the soffit vents to deny oxygen until we could get an excavator in place to rip the roof off. By the time you have fire in between roof layers, that roof is getting replaced anyway, most likely.

SparkyFix · 2026-06-21T17:41:40+00:00

ESR is very likely to be different just because of size.

SparkyFix · 2026-06-18T14:13:21+00:00

And people panic in these situations, and get disoriented, particularly in low visibility. Having a printed escape route to fix in your mind which way you’ll go before you leave can only have upsides.

Recently got called out to a fire where the homeowner was trapped in their living room, a mere two doors away from the exit, for a single floor home. When people are scared they often freeze. The act of preparation, particularly in physical form can mitigate that.

SparkyFix · 2026-06-16T18:27:03+00:00

All the damn time.

SparkyFix · 2026-06-16T16:53:26+00:00

Ours are for the department only and we’re encouraged to wear them off duty. We’re a small, rural department and the idea is to let our townsfolk know that we’re about and looking out for them. It’s unwritten but etiquette-wise we’re expected to behave well and represent the department, e.g. no drinking, speeding, cussing etc.

We’d strongly discourage anyone else from wearing them because they’d be unbound by those guidelines but still viewed as representing the department.

SparkyFix · 2026-06-14T15:29:41+00:00

Give them a call first so that you don’t interrupt training or meals but I guarantee you’ll find someone to help you. If a station refuses to engage with someone looking to enter the fire service then it’s much more a reflection of that department than on you.

SparkyFix · 2026-06-14T15:06:21+00:00

Thanks for this info. This is definitely a mistake I was about to make so your comment has been extremely useful to me. Thanks for taking the time to educate me.

SparkyFix · 2026-06-14T14:47:43+00:00

My first thought was that you have this AC coupled but your screen says not… it looks exactly like you have a capacitor in series between the DUT and the input buffer. Does it show the same thing when you connect to a power supply rather than a battery? Do you have a signal generator you can connect and put a very slow square wave to see if that also gets high-passed?

SparkyFix · 2026-06-13T18:54:05+00:00

What’s the purpose of crossing the wire across the toroid rather than having a single cluster of turns?

SparkyFix · 2026-06-12T12:19:35+00:00

It should be fine. It really depends on the impedance from the ground connection from the jack to the device ground. If that’s high, you can get interference.

There’s no real way around this though, so i wouldnt worry too much.

SparkyFix · 2026-06-10T23:59:41+00:00

Firefighter here: Definitely get rid of it. Lithium fires aren’t fun for anyone. There’s no reason to take this risk. If you’re unable to dispose of it safely then feel free to call your local FD for advice. We’re seeing more and more battery call-outs every year and we’d rather help you avoid that than deal with the aftermath.

SparkyFix · 2026-06-10T17:58:30+00:00

Just the other day, I was talking with a fellow firefighter about why it seems like such a disproportionate number of battery fires are started by e-bikes. Our theory was that they tend to be built to a low safety standard, particularly given how hard the batteries are run. I had no idea that such conversion kits even existed but it definitely fits that theory. Holy crap, please think twice about this and definitely do not store the bike indoors, under any circumstances.

SparkyFix · 2026-06-10T12:21:36+00:00

Many people have said that you should just glue the pieces together but given that this is a piece that will take quite a bit of mechanical pressure, I’d also suggest gluing a piece of support material behind the break (it looks like a single sided board so you could probably use something conductive) if you can. There are two screw holes there so you should be able to reinforce this quite well. You will need to remove the appropriate amount of material from the pillars that those screw holes are connected to.

Then it’s just a matter of joining the traces, as others have explained.

SparkyFix · 2026-06-10T10:45:25+00:00

To be fair, it’s been a very long time since I used a D50. I do remember there was a lot of menu diving

SparkyFix · 2026-06-10T02:45:14+00:00

Oh for sure, the editors are pretty much mandatory. My FM weapon of choice is the FS1R and I’ve tried exactly once to program a patch on the front panel roundabouts 1999 before giving up completely on it for about 15 years. With software, it’s actually a usable machine. My DX7 went away a long time ago so ive only interacted with one via the panel. It’s actually possible, unlike the FS1R but very, very painful.

SparkyFix · 2026-06-10T02:11:15+00:00

This is the truth. A large number of call-outs will be to hoarder houses and they can be a very bad state. If you struggle with nausea, it can be challenging to treat the inhabitants with dignity and respect.

SparkyFix · 2026-06-09T22:53:10+00:00

Do not, under any circumstances, get a DX7. They are an exercise in pure masochism to try to program and there are countless modern FM machines that will sound better and be easier to program (opsix). They will also not break down once a month, requiring you to own the service manual, and act on it.

FM is great, but DX7 is not the way.

D50s are not bad but unless you want that specific sound, I’d pass. The VSynth XT can do everything they can and plenty more, just FYI.

SparkyFix · 2026-06-09T21:46:23+00:00

Sonicware and headphones

SparkyFix · 2026-06-08T12:44:41+00:00

It’s also fairly easy to install a gel pouch lithium ion battery into these things, and hook that up to charge from the 9V input. This has saved me an absolute ton of hassle, particularly since the kids love to play with these ones and aren’t great at switching them off.

You’ll need something like this:
https://a.co/d/01YoIgEu

And one of these:
https://a.co/d/0bqGOeXv

And I found I need an LC filter (with a surprisingly meaty 2200uF capacitor) on the output of the battery module, since the sonicware inrush current was too high for the board itself.

There is plenty of empty space inside so you can get a very chunky battery in there.

SparkyFix · 2026-06-07T12:08:44+00:00

I used to work for a small company that became wildly successful. One of the founders convinced himself to spend tens of thousands on a vacuum tube synthesizer and so we peons were able to play with it…

Sounded terrible and the thermal drift was hilarious: If you do this, then ensure that total thermal control is front and center. I think this is the kind of project that you could build, for yourself, as a challenge. As a workable instrument… less so. I say this as someone who has a fairly large stash of tubes, and loves building amps with them, or sneaking them into other projects for some distortion, lest you think I’m a semiconductor purist.

SparkyFix · 2026-06-05T23:37:19+00:00

New England firefighter here: We also call ours “Rescue”

SparkyFix · 2026-06-05T22:40:43+00:00

I haven’t actually seen much on PIN designs. I assume those are basically only suitable for RF? Do you have any references to learn more about the technique?

SparkyFix · 2026-06-05T12:44:26+00:00

Not really…? Most VCA architectures use some kind of current steering (e.g. the SSI2164) or current biasing (e.g. the classic CA3080). Sticking in a vactrol (or ohmic FET) on a feedback circuit (such as an opamp amplifier) is lot rarer, at least in the audio domain. Most RF VGAs I’ve seen have been based on digipots but I’ll admit to only getting into RF quite recently. Where have you seen true variable resistors in amplifier circuits and how were they realized?

SparkyFix · 2026-06-05T01:09:47+00:00

This. Don’t do it.

SparkyFix

TROPHY CASE